1. business and industrial
2. chemicals industry
3. plastics and polymers

Purity by SPE
Oasis® Sample Extraction Products
®
SAMPLE EXTRACTION PRODUCTS
Waters Oasis® Family of Sample Extraction Products
The Oasis® family of sample extraction products is designed to simplify and
improve your sample preparation by combining the right sorbent chemistry, device
format and methodology. Achieve robust, selective, and sensitive solid-phaseextraction [SPE] methods without worrying about low recoveries caused by breakthrough, sorbent drying, pH limitations, and undesirable silanol activity.
Oasis® SPE sorbents—covered by eight U.S. patents*—are unique in their purity,
reproducibility, stability, and retention characteristics. Today, they are the most
widely used polymeric SPE products in bioanalytical laboratories.
Our ongoing goal for nearly three decades has been to provide innovative
and flexible sample preparation tools for the separation scientist. In 1996, we
introduced the first hydrophobic, yet water-wettable, polymeric SPE sorbent,
Oasis® HLB, designed for fast, generic, reversed-phase SPE. A year later, we
introduced advanced, novel, 2-D methodologies using Oasis® HLB to achieve
cleaner, more selective extracts. In 1999, we introduced two mixed-mode strong
ion-exchange chemistries—Oasis® MCX and MAX—enabling highly selective and
sensitive generic protocols for basic and acidic compounds, respectively. In 2004, we
introduced mixed-mode weak ion exchangers—Oasis® WCX and WAX—to extract
selectively strongly basic and strongly acidic compounds, respectively.
In 2005, we introduced the Oasis® 2x4 Method, a simplified strategy for
method development that provides a straightforward approach to the selection
of the SPE sorbent and protocol. The Oasis® 2x4 Method produces the cleanest
extracts for analytic confidence by eliminating effects due to matrix interferences
and sample variability.
We are committed to developing products and procedures that improve
sample preparation performance. When it comes to device design and
development, our goals are innovation and flexibility. Witness our awardwinning Oasis® 96-well plate design**, on-line Oasis® SPE columns, and our
innovative, patented Oasis® µElution plate*** that, for the first time, enables
SPE elution volumes as low as 25 µL.
No matter what your sample prep challenge is,
if you can do it by SPE, Oasis® SPE can do it better!
*U.S. patents 5,882,521; 5,976,367; 6,106,721; 6,254,780; 6,322,695; 6,468,422; 6,726,842; 6,773,583
**R&D 100 Award, 1999
***U.S. Patent No. 6,723,236
Table of Contents
Why Solid-Phase Extraction (SPE)? . . . . . . . . . . . . . . . . . . . . 2
Part I: Chemistry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Oasis® HLB . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Oasis® MCX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Oasis® MAX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Oasis® WCX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Oasis® WAX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Part 2: Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Oasis® Family of SPE Products . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
µElution Plates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Plates and Cartridges . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
On-Line Columns . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Part 3: Methodology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Oasis® 2x4 Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Oasis® 2x4 Optimized Methodology . . . . . . . . . . . . . . . . . . . . . . . 16
Oasis® HLB Generic Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Oasis® HLB Optimized Methodology . . . . . . . . . . . . . . . . . . . . . . 19
Oasis® Advanced Methodology . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Ordering Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Why Solid-Phase Extraction (SPE)?
Sample preparation is a key component of every analytical method (such as
LC/MS/MS). By some estimates, 60-80% of the work activity and operating
cost in the analytical laboratory is spent preparing samples for introduction
into an instrument.
The importance of sample preparation, particularly SPE, stems from four major
concerns—eliminating matrix effects including reducing ion suppression,
concentrating analyte(s) of interest, and improving analytical system performance.
For high sensitivity analyses, such as those employing UPLC™/MS/MS, proper sample preparation can be critical for minimizing
matrix effects and concentrating analytes of interest. Oasis® sample preparation can be used with UPLC™/MS/MS systems
to provide the cleanest extracts. The system shown here integrates the Waters® Quattro Premier™ XE Mass Spectrometer with the
Waters ACQUITY UPLC™ system using MassLynx™ 4.1 Software.
SPE Offers Solutions to These Major Sample Preparation Concerns
Eliminating Matrix Effects
Concentrating Analyte(s) of Interest
Solid-phase extraction (SPE) has proven to be an effective tool for removing
interferences, enabling sensitive, selective, and robust LC/MS/MS analysis.
Frequently, compounds of interest are present at levels too low for accurate and
precise quantitation. SPE enables the enrichment of selected analytes without
concentrating the interferences.
Reducing Ion Suppression
Improving Analytical System Performance
Oasis® SPE products successfully remove phospholipids and lyso-phospholipids,
key contributors to ion suppression in LC/MS/MS analysis. Removal of these
interferences results in an increase in MS response, hence lowering the LOQ.
Advances in SPE technology, combined with robotic automation, make SPE not
only a cost-effective, but also a time-efficient, sample-preparation technique. This
improves analytical system performance by:
• Introducing the analyte(s) in an MS compatible solvent
• Extending analytical column lifetime, reducing system
downtime/maintenance
• Minimizing ion suppression to improve signal response
1
Chemistry
Waters Innovations in Solid-Phase Extraction
In 1996, Waters revolutionized SPE technology with the introduction of Oasis® HLB, the first waterwettable—yet hydrophobic—polymeric sorbent, permanently changing SPE practice. The Oasis® family
includes five patented SPE chemistries for all your sample preparation needs:
Oasis® HLB: Hydrophilic-Lipophilic-Balanced reversed-phase
sorbent for acids, bases and neutrals
Oasis® MCX: Mixed-mode Cation-eXchange
reversed-phase sorbent for bases
Oasis® MAX: Mixed-mode Anion-eXchange
reversed-phase sorbent for acids
Oasis® WCX: Mixed-mode Weak Cation-eXchange reversed-phase
sorbent for strong bases (e.g., quaternary amines)
Oasis® WAX: Mixed-mode Weak Anion-eXchange reversed-phase
sorbent for strong acids (e.g., sulfonates)
Oasis® MAX
Oasis® MCX
Oasis® HLB
pKa <1
1 meq/g
Hydrophilic
Retention of Polars
Oasis® WCX
pKa >18
0.25 meq/g
Lipophilic
RP Retention
Oasis® WAX
Water-wettable
Stable from pH 0–14
No silanol interactions
pKa ~6
0.6 meq/g
pKa ~5
0.75 meq/g
Oasis® HLB Chemistry
Universal Sorbent for Acidic, Neutral,
and Basic Compounds
Oasis® HLB is a Hydrophilic-Lipophilic-Balanced, water-wettable, reversed-phase
sorbent for all your SPE needs. It is made from a specific ratio of two monomers,
hydrophilic N-vinylpyrrolidone and lipophilic divinylbenzene. It provides superior
reversed-phase capacity with a neutral polar ‘hook’ for enhanced retention of
polar analytes.
Unique Water-Wettable Oasis® HLB Copolymer
Waters has built a family of SPE sorbents which inherit some key features of
this unique substrate: stability at pH extremes and in a wide range of solvents,
extraordinary retention of polar compounds, and a relative hydrophobic retention
capacity 3x higher than that of traditional silica-based SPE sorbents like C18.
Water-wettable Oasis® sorbents exhibit excellent retention capacity for a
wider polarity spectrum of analytes, even if the sorbent bed runs dry during
conditioning or sample loading. This means that your SPE methods will be more
rugged and robust, obviating the need for repeat preparation.
N-VINYLPYRROLIDONE
The advantage of having higher retention capacity [k] is that more analytes
are retained with less breakthrough, improving the recovery and overall
reproducibility of your SPE method.
DIVINYLBENZENE
HYDROPHILIC-LIPOPHILIC BALANCE
Specific Surface Area: 810 m2/g, Average Pore Diameter: 80 Å
Total Pore Volume: 1.3 cm3/g, Average Particle Diameter: 30 µm or 60 µm
Available in five particle sizes [60 µm, 30 µm, 25 µm, 15 µm, and 5 µm],
Oasis® HLB sorbent, in cartridge, plate, or column format, allows you to
select the appropriate product based on the volume, viscosity, and turbidity
of your sample.
Exceptional Batch-to-Batch Reproducibility
Effect of Drying on Recovery
Long-term, batch-to-batch reproducibility of traditional silica-based mixed-mode
sorbents may be compromised by hydrolytic instability at pH extremes, relatively
low ionic capacity, and difficulties in bonding. To assure performance consistency
for large projects, careful analysts test for suitability, and then reserve successful,
specific lots of sorbent.
No impact of sorbent drying on HLB
High, consistent recovery
Oasis® HLB Cartridge (30 mg)
C18 Cartridge (100 mg)
100
100
Oasis sorbents have demonstrated excellent long-term, batch-to-batch
reproducibility for over ten years. Our careful process design and stringent
quality controls have set a new standard in batch-to-batch and lot-to-lot
reproducibility for SPE sorbents. Our entire Oasis® family of sorbents and
devices is manufactured in Waters ISO 9000 registered facilities in compliance
with cGMP guidelines of the U.S. Food and Drug Administration for Class 1
medical devices.
®
80
Procainamide
Acetaminophen
Ranitidine
Propranolol
Doxepin
60
40
20
0
0
% Recovery
% Recovery
80
60
40
20
5
10
Drying Time (minutes)
0
0
4
Drying Time (minutes)
Multiple batches of Oasis® HLB, MCX, MAX, WCX, and WAX have each
been used successfully on validated bioanalytical assays in a regulated
laboratory environment.
Batch-to-Batch Reproducibility of Oasis® HLB Sorbent — A Decade of Dramatic Consistency
% Recovery
No Batch Reservations Needed: Consistently high recoveries over more than 10 years of production.
105
95
85
Recovery for:
Procanamide – 1.90% RSD
Ranitidine – 1.68% RSD
Acetaminophen – 1.65% RSD
8
Oasis® MCX Chemistry
Mixed-Mode Cation-eXchange and Reversed-Phase Sorbent
High Selectivity and Sensitivity for Basic Compounds
Oasis® MCX is designed to overcome the limitations of traditional silica-based
mixed-mode SPE sorbents. It is a strong mixed-mode cation exchange, waterwettable, polymeric sorbent made reproducibly by a novel, Waters-patented
process. Oasis® MCX provides dual modes of retention—ion exchange, and
reversed phase—on a single, clean, stable, high-surface-area, organic co-polymer
that is stable from pH 0 to 14.
Drug–Sorbent Interactions on Oasis® MCX Sorbent
Highly selective retention enables much stronger washes,
resulting in very clean extracts.
O
In addition to the pH stability typical of DVB polymers, Oasis® MCX has far greater
binding capacity than that of silica-based mixed-mode SPE sorbents. The ability to
fully manipulate pH [0–14] during the development, optimization, and use of SPE
methods on mixed-mode sorbents enables not only fast, straightforward, method
development, but also ensures very rugged and robust procedures. There is no
N
MCX sorbent
Mixed-mode Cation eXchange
SO–3
SO–3
analyte breakthrough or loss of recovery due to dissolving silica particles at high pH
or cleaving bonded phase at low pH.
Effective use of mixed-mode SPE sorbents for extraction of basic compounds
from biological matrices (such as plasma, urine, bile, and tissue homogenates)
requires high capacity (both reversed-phase for the retention of interferences and
ion-exchange for selective retention of analytes). Typical silica-based mixed-mode
sorbents are synthesized in a complex process that is hard to control, and they
have relatively low exchange capacities, ranging from 0.06–0.2 meq/g.
The novel, well-controlled Waters production process reproducibly delivers
Oasis® MCX with 1.0 meq/g of sulfonic-acid-ion-exchange capacity. Two particle
sizes [60 µm and 30 µm] are available.
Strong cationexchange mode
Best retention at least
2 pH units below pKa
of the analyte
Reversed-phase
interaction
+
N
H H
O
CH 3
OH
Sulfonic-acid-cationexchange capacity:
1.0 meq/g
Oasis® MAX Chemistry
CH 3
Propranolol
(basic drug)
Drug–Sorbent Interactions on Oasis® MAX Sorbent
Mixed-Mode Anion-eXchange and Reversed-Phase Sorbent
Highly selective retention enables much stronger washes,
resulting in very clean extracts.
High Selectivity and Sensitivity for Acidic Compounds
Oasis® MAX is designed to overcome the limitations of traditional silica-based
mixed-mode SPE sorbents. It is a strong mixed-mode anion-exchange, waterwettable, polymeric sorbent stable from pH 0 to 14. Now you can employ
reliable SPE in methods to detect, confirm, or quantify acidic compounds and/
or acidic metabolites in biological fluids. SPE procedures using the selectivity
and ruggedness of Oasis® MAX enable separation of analytes from complex
samples into two fractions: acidic compounds and basic/neutral compounds.
Fractionated extracts can be analyzed by multiple analysis methods or even
multiple techniques [LC/MS and GC/MS].
O
MAX sorbent
Mixed-mode Anion eXchange
N
CH 3
+
CH 2 N C H
4 9
R+
Reversed-phase
retention
The novel, well-controlled Waters production process reproducibly delivers
Oasis® MAX with 0.3 meq/g of quaternary-amine-ion-exchange capacity.
Quaternary-amineanion-exchange capacity:
0.3 meq/g
Two particle sizes [60 µm and 30 µm] are available.
CH 3
COO–
S
O
CH 3
Strong anionexchange mode
Best retention at least
2 pH units above pKa
of the analyte
Suprofen
(acidic drug)
Oasis® WCX Chemistry
Drug-Sorbent Interactions on Oasis® WCX Sorbent
Highly selective retention enables much stronger washes,
resulting in very clean extracts.
Mixed-Mode Weak Cation-eXchange
and Reversed-Phase Sorbent
High Selectivity and Sensitivity for Strongly Basic Compounds
O
Oasis® WCX is designed to provide superior sample preparation for strong bases
and quaternary amines. It is a weak-cation-exchange, mixed-mode, water-wettable,
polymeric sorbent, stable from pH 0 to 14. Oasis® WCX has all the advantages
of Oasis® HLB. Rugged and highly selective SPE methods using Oasis® WCX
detect, confirm and quantify strongly basic compounds and quaternary amines in
biological fluids.
N
WCX sorbent
Weak Cation eXchange
COO Weak cation-exchange
interaction
CH 3 O
The novel, well-controlled Waters production process reproducibly delivers
Oasis® WCX with 0.7 meq/g of carboxylic-acid-ion-exchange capacity. Three
particle sizes [60 µm, 30 µm, and 5 µm] are available.
Reversed-phase
interaction
H3 C
CH 3
O
N
+
CH 3
CH 3
Carboxylic-acid-cationexchange capacity: 0.7 meq/g
Oasis® WAX Chemistry
Drug-Sorbent Interactions on Oasis® WAX Sorbent
Mixed-Mode Weak Anion-eXchange
and Reversed-Phase Sorbent
Highly selective retention enables much stronger washes,
resulting in very clean extracts.
High Selectivity and Sensitivity for Strongly Acidic Compounds
O
Oasis WAX is designed to provide superior sample preparation for strong
acids. It is a weak-anion-exchange, mixed-mode, water-wettable, polymeric
sorbent, stable from pH 0 to 14. Oasis® WAX has all the advantages of
Oasis® HLB. Rugged and highly selective SPE methods using Oasis® WAX
detect, confirm, and quantify strongly acidic compounds in biological fluids.
®
N
WAX sorbent
Weak Anion eXchange
+
NH
The novel, well-controlled Waters production process reproducibly delivers
Oasis® WAX with 0.6 meq/g of piperazine-ion-exchange capacity. Three
particle sizes [60 µm, 30 µm, and 5 µm] are available.
SO–3
Reversed-phase
interaction
Piperazine-anion-exchange
capacity: 0.6 meq/g
+
NH2
Weak anion-exchange
interaction
2
Format
Oasis® Family of SPE Products
The entire Oasis® family of sorbents and devices is manufactured in Waters ISO 9000 registered facilities in
compliance with cGMP guidelines of the U.S. Food and Drug Administration for Class 1 medical devices.
Oasis® µElution Plates
Oasis® 96-Well Extraction Plates
Oasis® Syringe-Barrel Cartridges
Oasis® Glass Cartridges
Oasis® Symbiosis™ Cartridges
Oasis® On-Line Columns
Oasis® Family of SPE Products
Oasis® µElution Plates
• Patented µElution plate design*
• Enabling technology facilitates elution volumes as low as 25 µL
• No evaporation and reconstitution necessary; just elute and shoot
• Ideal for small sample volumes
• Up to a 25x increase in concentration
• Compatible with most liquid-handling robotic systems for
automated, reliable high-throughput SPE (HT-SPE)
* U.S. patent 6,723,236
Oasis® 96-Well Extraction Plates
• Innovative two-stage well design (1999 R&D 100 Award winner)
• High throughput and high recovery
• Available in 5 mg, 10 mg, 30 mg, and 60 mg per well
• Compatible with most liquid-handling robotic systems for
automated, reliable high-throughput SPE (HT-SPE)
Oasis® Syringe-Barrel Cartridges
• Ultra-clean syringe barrel and frits
• Available in cartridges ranging from 1 cc to 60 cc
• Flangeless syringe-barrel cartridges available: 1 cc, 3 cc, 6 cc
• Also available: Plus cartridges with Luer inlet hub and outlet tip, 225 mg
Oasis® Glass Cartridges
• Ultra-clean glass syringe with Teflon® frit
• Endocrine disruptors analysis at part-per-trillion levels
• Available in 5 cc (200 mg) configuration
Oasis® Cartridges for Prospekt™ 2/
Symbiosis™ Systems
• Cartridge format for use with Spark Holland
Prospekt™ 2/Symbiosis™ systems
• Narrow-bore PVDF cartridge, 1 x 10 mm,
contains 2.5 mg of Oasis® sorbent
• Available with all five patented Oasis® sorbents—
HLB, MCX, MAX, WCX and WAX
• High recovery and reproducible results
for a wide range of compounds
Oasis® On-Line Columns
• Rugged, reproducible, ultra-fast, on-line analysis
• Compatible with all on-line analysis systems
• Wide choice of configurations, particle sizes,
and sorbent chemistries
• Sensitivity equal to that of off-line SPE
technique is achievable
Oasis® µElution Plates
Waters Latest Innovation in SPE Technology
• Elute in as little as 25 µL with no evaporation/reconstitution
• Ideal for small sample volumes
• Up to a 25x increase in sensitivity
Combine patented Oasis® µElution plate design, proven Oasis® chemistries,
and detailed protocols to enable elution volumes as low as 25 µL. Now, for the
first time, you can perform SPE cleanup and analyte enrichment on very small
sample volumes.
Oasis® µElution Technology vs. Disk Technology
Comparison of µElution vs. Disk Technology
There are two predominant low-elution SPE technologies in the marketplace
today: SPE Disk and Oasis® µElution. These technologies differ greatly in
performance primarily because of three features: aspect ratio, holdup volume,
and elution volume.
µElution Technology
There is a correlation between a sorbent bed’s aspect ratio [height to diameter,
H/D] and its performance in an SPE device. An H/D ratio less than 1.0 often
compromises extraction efficiency. In SPE disk design (e.g. membrane/glass-fiber
disk), a small mass of sorbent is embedded in a thin support structure having
good flow properties but a small aspect ratio, H/D=0.13. In contrast, the Oasis®
µElution technology uses an internally tapered well, packed with high capacity
Oasis® sorbent, having an aspect ratio, H/D=1.15, nearly 9x that of SPE disk
technology. An Oasis® µElution plate well functions more like a chromatography
column, minimizing loss of analyte during critical steps in the SPE procedure and
enhancing overall extraction efficiency.
Disk Technology
Wide and Short
Sorbent Bed
Narrow and Tall
Sorbent Bed
A small holdup volume is necessary to minimize elution volume. SPE disks have
holdup volumes in the 35–65 µL range, compared to that for an Oasis® µElution
bed plus frits which measures as little as 15 µL. Having 2–4x less holdup volume
minimizes elution volume and reduces analyte loss during elution, improving both
recovery and precision.
Ratio Bed H/D = 1.15
Ratio Bed H/D = 0.13
Vacuum
Vacuum
Recovery Comparison of µElution vs. Disk Technology
Minimizing SPE elution volume is critical for SPE performance, recovery, and
precision. Normal elution volume range for an Oasis® µElution plate is only
The innovative features of the Oasis® µElution plates enable sensitive,
robust, reproducible results without evaporation and reconstitution.
25–50 µL, far lower than the 75–300 µL typical for SPE disk technology.
Reproducible elution in only 25 µL enhances and streamlines SPE methods. SPE
can be performed on very small sample volumes. Sample enrichment increases as
much as 15-fold. A time-consuming step for eluate concentration by evaporation
is no longer needed—neither is evaporation/reconstitution if the eluting
solvent is properly chosen to be compatible with the LC/MS mobile phase.
The innovative features of Oasis® µElution plates enable sensitive, robust,
reproducible results without evaporation and reconstitution. Analytical performance,
in terms of sensitivity, selectivity, and ruggedness, is superior.
Oasis® µElution Technology
Disk Technology
>85% Recovery in 25 µL
Minimum of 100 µL needed for best result
25 µL
100
75 µL
75 µL
Elution Volume
80
% Recovery
75 µL
60
40
20
0
Oasis® HLB
Brand E–C1
Brand E–UR
Brand S–C1
µElution plate
100 µL Spiked Saline
acetaminophen
practolol
10
N-acetylprocainamide
betamethasone
caffeine
naproxen
amitriptyline
propranolol
Oasis® 96-Well Plates
Versatile, High-Throughput Oasis® 96-Well Extraction Plates
Waters award-winning plate design, with five chemistry and four sorbent-mass
options, provides flexible high-throughput SPE in a single device. The Oasis®
96-well plates are designed to be used on many manifold configurations and most
robotic liquid handling systems. Oasis® sorbents’ unique balance of hydrophobicity
and water-wettability means you will never have to worry about poor results if
individual wells of the 96-well plate dry out. As always, you can expect Oasis®
SPE products to perform reliably, delivering high and reproducible recoveries
for a wide range of analytes, including polar and basic compounds, with RSDs
less than 5% [n=96].
Waters 96-Well Plate Design
1999 R&D
100 Award
Two-Stage
Well Design
5 mg
10 mg
30 mg
60 mg
By varying frit size and/or placement, the same plate may be filled
with various quantities of sorbent per well. Our design permits optimal
recoveries, even with low sorbent weights for smaller elution volumes.
Oasis® Cartridges for Prospekt™ 2/Symbiosis™ Systems
On-Line SPE with Oasis® Sorbent in Prospekt™ 2/Symbiosis™ Cartridges
Waters Oasis® sorbents are available in Prospekt™ 2/Symbiosis™ cartridges for
use with Spark Holland Symbiosis™ systems. Each narrow-bore PVDF cartridge is
1.0 mm x 10 mm and contains approximately 2.5 mg of Oasis® sorbent.
The Oasis® sorbents in Prospekt™ cartridges show the same performance
advantages as in other Oasis® formats for pharmaceutical compounds when
compared to silica-based sorbents. Available with all five patented Oasis®
sorbents—HLB, MCX, MAX, WCX, and WAX.
Recovery Comparison: Oasis® HLB vs. Bonded-Silica Symbiosis™ Cartridge
Oasis® HLB
C18
C2
0
20
60
40
80
% Recovery
Clonidine
Terconazole
*Data provided by Dr. Francis Beaudry, Principal Research Scientist,
Phoenix International Life Sciences, Inc., Montreal, Quebec, Canada.
11
100
Oasis® On-Line Columns
Ultra-Fast On-Line SPE for LC/MS/MS
Ultra-fast on-line analysis can improve the speed and throughput of LC/MS
analysis of small molecules from biological sample matrices. There are three Oasis®
On-Line column configurations designed to fit all your on-line-analysis needs.
1
2
• The Oasis® Cartridge Column fits into a Sentry™ holder that features
a finger-tight fitting for fast, convenient replacement [1].
• The Oasis® Direct-Connect Column can be screwed directly into a switching
valve or connected to fittings like those for a conventional HPLC column [2].
3
• The Oasis® Column features traditional HPLC column
fittings and hardware [3].
All of these formats are available with the five Oasis® patented sorbents
(HLB, MCX, MAX, WCX, WAX) in a wide choice of particle sizes and
Ultra-fast on-line analysis of multiple analytes can also be accomplished using the
Oasis® On-Line column combined with appropriate Waters narrow-bore analytical
dimensions. The Oasis® On-Line columns make it possible to analyze a specific
analyte or metabolite in a complex sample matrix (such as plasma or serum).
No off-line sample preparation is needed; just dilute the sample and inject.
columns (such as XBridge™, SunFire™, Atlantis®, XTerra®, or Symmetry® columns).
Ultra-Fast On-Line System Configuration
LOAD
Oasis®
On-Line Column
515
System
POSITION
Waste
10 Port Valve
2 positions
Gradient
HPLC
Narrow Bore
Analytical Column
Waste
10
8
3
7
4
5
6
Mass
Spectrometer
9
2
Waste
Alliance® HT
Mass
Spectrometer
10
1
9
3
8
4
5
6
7
Oasis®
1
2
Oasis®
Isocratic
HPLC
INJECTION
515
System
POSITION
Alliance® HT
Mass
Spectrometer
Analytical
Column
Analytical
Column
Oasis® On-Line Column Lifetime — 1203 Injections of Haloperidol in Plasma
Oasis® HLB 25 µm column
2.1 x 20 mm
Rat plasma sample treatment steps:
protein precipitation with CH3CN [1:3];
using a Sirocco™ Protein Precipitation Plate
50 µL injection
Load in H2O at 4 mL/min
Rapid gradient at 0.4 mL/min
100% A to 100% B in one minute
A: MeOH/2% aq. formic acid 5/95
B: MeOH/2% aq. formic acid 95/5
Injection #
1
1203
Back Pressure
357 psi
1103 psi
Every 100th injection plotted here
0
1
2
Excellent reproducibility
12
3
4 min
3
Methodology
SPE method development starts with knowledge of the sample matrix—the nature and relative concentration of
the analytes of interest as well as of potentially interfering endogenous compounds. Then, judicious choices
of sorbent and solvents for load, wash, and elute steps create rugged, reliable, selective protocols.
Waters application chemists have devised several approaches to streamline this process.
Oasis® 2x4 Method
This novel strategy for piloting SPE protocols for acids, bases, and
neutrals will revolutionize the practice of SPE methods development.
Capitalizing on the capability of ion-exchange sorbents—all of which
are derivatives of HLB [see page 3]—the Oasis® 2x4 Method will
provide high recoveries for most analytes on the first try.
Oasis® 2x4 Optimized Methodology
Systematic optimization of wash and elute steps further
refines the power of the Oasis® 2x4 Method.
Oasis® HLB Generic Method
Isolate a broad range of acidic, basic, and neutral
compounds from a wide spectrum of matrices.
Oasis® HLB Optimized Methodology
Vary pH as well as organic solvent concentration to add a
second dimension for more selective removal of interferences
and to enhance specificity for ionizable compounds.
Oasis® Advanced Methodology
Solve sample preparation problems that were
traditionally considered difficult, if not impossible.
13
3A: Oasis® 2x4 Method
Oasis® 2 4 Method
Only 2 protocols and 4 sorbents to
analyze all types of compounds:
acids, bases, and neutrals
The Oasis® 2x4 Method is a simple, logical approach
to the selection of an SPE sorbent and protocol. Two
protocols and four sorbents provide the flexibility
to extract acids, bases, and neutrals with high SPE
recoveries while removing matrix components that
may interfere with analysis.
Follow the simple steps outlined in this flow chart to
achieve high recoveries and the cleanest extracts:
For Bases
pKa 2-10:
Use Oasis® MCX
• Characterize your analyte [Neutral,
For Strong Acids
pKa < 1:
Use Oasis® WAX
For Acids
pKa 2-8:
Use Oasis® MAX
For Strong Bases
pKa > 10:
Use Oasis® WCX
Acid or Base, pKa].
• Select one of the four Oasis® sorbents.
Apply Protocol 1
Apply Protocol 2
Prepare Sample
Prepare Sample
Condition/Equilibrate
Load Sample
Condition/Equilibrate
Load Sample
Wash:
2% Formic Acid
Wash:
5% NH4OH
• Apply the indicated Protocol [1 or 2].
• Determine SPE recoveries by LC analysis.
Elute 1:
100% MeOH
Weaker
Acids
Elute 2:
5% NH4OH in MeOH
Note that neutral analytes can be isolated from any of
the four sorbents in the Elute 1 step of either protocol.
Choose the particular ion-exchange sorbent that is
best at removing specific matrix interferences. A good
example of this is shown below.
Base
100%
%
50
3.26
3.16
1: MRM of 5 Channels ES+
TIC
2.55e7
3.08
2.52
2.60
Oasis ® MCX — Protocol 1
%
100
Protein
Precipitation
2.50
%
100
2.522.60
Oasis ® WAX — Protocol 1
2.50
2.60
%
100
Oasis ® MAX — Protocol 2
100
Oasis WCX — Protocol 2
®
2.52
2.60
%
0
Monitoring 5 Phospholipid
MRM Transitions
Cleanliness of 100% MeOH Elute 1
100
0
1.75
2.00
2.25
2.50
2.75
3.00
100% Phospholipids
1: MRM of 5 Channels ES+
TIC
2.55e7
2% Phospholipids
1: MRM of 5 Channels ES+
TIC
2.55e7
9% Phospholipids
1: MRM of 5 Channels ES+
TIC
2.55e7
11% Phospholipids
1: MRM of 5 Channels ES+
TIC
2.55e7
12% Phospholipids
3.25
3.50
O
3.75 4.00 Min
O
Recovery is high on all four Oasis® sorbents, but removal of
phospholipids, a primary cause of matrix ion suppression,
is best on Oasis® MCX. Protein precipitation is a poor choice
for sample preparation prior to LC/MS/MS analysis.
H
Strong Base
Oasis® Sorbent Selection Plate:
Evaluating Oasis® 2x4 Method for Cephalexin
OH
0
OH
H
Acid
New Oasis® Sorbent Selection Plate and Cartridge Kits enable rapid
development of SPE methods for LC/MS analysis. Having all four Oasis® ionexchange sorbents [MCX, MAX, WAX and WCX] in a single plate is convenient
for scouting the best ways to accomplish efficient isolation of unknowns, zwitterionic
compounds, or mixtures of analytes with different retention/elution properties.
Example: Prednisone in Plasma
SPE Recovery
Elute 2:
2% Formic Acid in MeOH
Strong Acid
Choosing Optimum Sorbent and Protocol for Neutral Compounds
Weaker
Bases
Elute 1:
100% MeOH
Neutrals
SPE Recovery
50
O
100%
Oasis® MCX
H
O
Protocol 1 – Elute 2
Prednisone
Oasis® WAX
Protocol 1 – Elute 1
Oasis® MAX
Protocol 2 – Elute 2
Oasis® WCX
NH2
pKa = 7.3
H H
N
H
O
S
N
HO
O
pKa = 2.6
Cephalexin
[Cephalosporin antibiotic]
A difficult amphoteric analyte
Protocol 2 – Elute 1
Aliquots of prepared sample processed using Oasis® 2x4 Method protocol designated for each
of 4 sorbents. Eluates from Elute 1 and Elute 2 steps analyzed by LC/MS/MS.
Clearly, Oasis® MCX is the sorbent of choice.
14
Oasis® 2x4 Method—Proof-of-Concept
To demonstrate the logic, simplicity, and effectiveness of the Oasis® 2x4 Method,
five rat plasma samples were prepared, each containing one of these characterized test analytes:
• Imipramine, a base – pKa of conjugate acid = 9.4
The neutral analyte was processed on all four sorbents, as shown on the previous
page. Of the four method options, Oasis® MCX with Protocol 1 proved superior
at removing nearly all the phospholipids, eliminating this major source of matrix
effects, a known cause of ion suppression, loss of sensitivity, and inaccurate
quantitation in LC/MS analysis.
• Ibuprofen, an acid – pKa = 5.2
• Decanesulfonic acid, a strong acid – pKa < 0.5
• Valethamate, a quaternary amine [strong base]
– pKa of conjugate acid > 12
Essentially quantitative recovery and excellent cleanup efficiency were achieved for
each of the ionic or ionizable test analytes when the recommended Oasis® 2x4
Method sorbent/protocol combination was used. These results are shown in the
four figures below.
• Prednisone, a neutral compound
Each plasma sample was diluted [1:1, v/v] and acidified with phosphoric acid
[4% in water]. Respective aliquots were then processed using the protocol and
the Oasis® ion-mixed-mode sorbent designated by the Oasis® 2x4 Method
for the corresponding sample type. LC/MS/MS analysis was used to determine
SPE recoveries.
Oasis® 2x4 Method Test on MCX: Base Isolation
Oasis® 2x4 Method Test on WAX: Strong Acid Isolation
For Bases
pKa 2–10:
Use Oasis® MCX
Oasis® MCX
For Strong Acids
pKa < 1:
Use Oasis® WAX
Oasis® WAX
Protocol 1
Protocol 1
Imipramine
Decanesulfonic
acid
SPE Recovery: 108%
n=4, 2–18% RSD
SPE Recovery: 94%
n=8, 3–6% RSD
pKa <1
3.19
2.71
pKa ~6
MRM ES+
281.2 > 85.95
4.16e6
N
N
O
Imipramine [pKa = 9.4]
0
1
3
0
1
3
For Strong Bases
pKa > 10:
Use Oasis® WCX
Oasis® WCX
Protocol 2
Protocol 2
Ibuprofen
Valethamate
SPE Recovery: 100%
n=6, 6–13% RSD
SPE Recovery: 106%
n=4, 9–13% RSD
pKa ~5
2.63
2.71
O
MRM ES+
205 > 161
1.34e4
OH
O
N+
Br –
MRM ES+
306.2 > 163
2.10e6
O
Ibuprofen [pKa = 5.2]
0
1
5 min
Oasis® 2x4 Method Test on WCX: Strong Base Isolation
For Acids
pKa 2–8:
Use Oasis® MAX
pKa ~18
O– Na+
Decanesulfonic acid [pKa <0.5]
5 Min
Oasis® 2x4 Method Test on MAX: Acid Isolation
Oasis® MAX
S
MRM ES+
221.1 > 79.8
2.85e3
O
3
Valethamate [pKa >12]
5 min
15
0
1
3
5 min
3B: Oasis® 2x4 Optimized Methodology
Optimization of the Oasis® 2x4 Method on mixed-mode sorbents [MCX, MAX,
WCX, WAX] takes full advantage of two different chromatographic separation
mechanisms: reversed phase and ion exchange. Changes in pH are used to
manipulate the respective ionization states of the exchange sites on the sorbent
and of the acidic or basic moieties in analytes and interferences. In this way,
retention can be directed selectively to occur through either hydrophobic or ionic
interactions. Simultaneously, organic solvent concentration is modified to fine-tune
elution based upon relative hydrophobicity. The result is cleaner extracts that
eliminate matrix effects and enhance the sensitivity of the analytical method.
In the examples that follow, we will demonstrate how straightforward wash-elute
studies, in which the percentage of organic solvent is systematically varied, are
used to determine the optimal composition of SPE mobile phases for selective wash
and elution steps. Similar experiments may be designed for another variable such
as pH or ionic strength.
3B–1: Oasis® MCX 2x4 Method — Optimized for Bases
When the greatest selectivity and sensitivity for basic compounds [pKa 2–10] is
required to achieve the lowest limits of detection [LOD] and quantitation [LOQ],
optimization of Protocol 1 is recommended. As an example, a wash-elute study
was performed to determine the optimal retention and elution parameters for
imipramine on Oasis® MCX [below left]. These experimental data were then used
to optimize a selective Oasis® MCX SPE method [below right] to remove neutral,
acidic, and basic interferences.
Wash-Elute Study
Optimized Oasis® MCX Method for Imipramine
[% MeOH in water] : [conc. NH4OH] 95:5 v/v
Imipramine
N
10%
20%
30%
40%
50%
60%
70%
80%
90%
N
100%
Condition/Equilibrate:
1 mL methanol/water
Basic drug is loaded in
ionized [or neutral] form
if sample was pretreated
with acid [or base]
Load sample:
1 mL plasma or urine
Indicates Peak Area
of Analyte in LC Analysis
of Eluate
Maximum
% Organic Wash
Locks ionized drug on
strong cation-exchange
sites; removes proteins
and salts
Minimum
% Organic Elute
Wash 1:
1 mL 2% HCOOH
Removes interfering
acids [unionized] and
neutral compounds and
acidic interferences
Wash 2:
1 mL 100% MeOH
0
10
20
30
40
50
60
70
80
90
Neutralizes bases;
removes more polar
basic interferences
100
% MeOH in Water
Experiment for Oasis® MCX 96-Well Plate 30 mg
Wash 3:
1 mL 5% NH4OH in MeOH:H2O 55:45
Basic analyte is
eluted; hydrophobic
basic interferences
are retained
Elute:
1 mL 5% NH4OH in MeOH:H2O 95:5
A second example demonstrates the dramatic benefits of an optimized
solution [below left]. In this way, tertiary and aromatic amine interferences were
Oasis® MCX method for determining methamphetamine in urine. A wash-elute
study was used to find the best concentration of triethylamine [TEA] for Wash 3
removed selectively. As shown in the LC/UV data [below right], impressive RSDs
were achieved for quantitation of the primary and secondary amine analytes.
Oasis® MCX Urine Application:
Amphetamine and Methamphetamine
Optimized Oasis® MCX Method for Quantitation of Methamphetamine in Urine
Load:
10 mL spiked urine
(acidified with 100 µL 5 N HCI)
Locks ionized drug on
strong cation-exchange
sites; removes proteins
and salts
Blank without
TEA Wash
2 mL 5% MeOH in 0.1 N HCI
Wash 2:
2 mL 100% MeOH
Weak base removes
tertiary and
aromatic amines
0.01
Wash 1:
AU
Removes interfering
acids [unionized] and
neutral compounds and
acidic interferences
1
0.00
Wash 3:
3
2
1.5 mL 2.5% TEA in MeOH
0
Elute:
2
4
6
Blank with
2.5% TEA Wash
Spiked Sample
with 2.5% TEA Wash
2 mL 5% NH4OH in MeOH
4 µg/mL n=6
1. Amphetamine
2. Methamphetamine
3. Phentermine (I.S.)*
* Internal Standard
16
Results
Recovery
RSD
96.8%
90.4%
—
1.35%
4.01%
—
NH2
Amphetamine
H
N
Methamphetamine
NH2
Phentermine
3B–2: Oasis® WAX 2x4 Method — Optimized for Strong Acids
When the greatest selectivity and sensitivity for strong acids [pKa <1] is required
to achieve the lowest limits of detection [LOD] and quantitation [LOQ], optimization
of Protocol 1 is recommended. As an example, a wash-elute study was performed
to determine the optimal retention and elution parameters for decanesulfonic
acid on Oasis® WAX [below left]. These experimental data were then used to
optimize a selective Oasis® WAX method [below right] to remove neutral, basic, and
acidic interferences.
Wash-Elute Study
Optimized Oasis® WAX Method for Decanesulfonic Acid
[% MeOH in water] : [conc. NH4OH] 95:5 v/v
10%
20%
30%
40%
50%
60%
70%
80%
O
90%
S
O
O– Na+
Decanesulfonic Acid
100%
Condition/Equilibrate:
1 mL methanol/water
Load sample:
1 mL plasma or urine
Indicates Peak Area
of Analyte in LC Analysis
of Eluate
Wash 1:
Maximum
% Organic Wash
1 mL 2% HCOOH
Minimum
% Organic Elute
Removes interfering
bases [ionized] and neutral
compounds [including
unionized acids]
0
10
20
30
40
50
60
70
80
90
100
% MeOH in Water
Wash 2:
1 mL 100% MeOH
Wash 3:
1 mL 5% NH4OH in MeOH:H2O 25:75
Experiment for Oasis® WAX 96-Well Plate 30 mg
Strongly acidic analyte is
eluted; more hydrophobic
acidic interferences
are retained
Ionizes weak anionexchange sites to
lock on analytes; removes
proteins and salts
Elute:
Neutralizes anionexchange sites; removes
more polar strongly
acidic interferences
1 mL 5% NH4OH in MeOH:H2O 80:20
3B–3: Oasis® MAX 2x4 Method — Optimized for Acids
When the greatest selectivity and sensitivity for acidic compounds [pKa 2–8] is
required to achieve the lowest limits of detection [LOD] and quantitation [LOQ],
optimization of Protocol 2 is recommended. As an example, a wash-elute study
was performed to determine the optimal retention and elution parameters for
ibuprofen on Oasis® MAX [below left]. These experimental data were then used
to optimize a selective Oasis® MAX SPE method [below right] to remove neutral,
basic, and acidic interferences.
Wash-Elute Study
Optimized Oasis® MAX Method for Ibuprofen
OH
[% MeOH in water] : [conc. HCOOH] 98:2 v/v
O
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
Ibuprofen
Condition/Equilibrate:
1 mL methanol/water
Acidic drug is loaded in
ionized [or neutral] form
if sample was pretreated
with base [or acid]
Indicates Peak Area
of Analyte in LC Analysis
of Eluate
Maximum
% Organic Wash
Minimum
% Organic Elute
20
30
40
50
60
70
80
90
Wash 1:
1 mL 5% NH4OH
Removes interfering
bases [unionized] and
neutral compounds
0
10
Load sample:
1 mL plasma or urine
100
Wash 2:
1 mL 100% MeOH
Wash 3:
% MeOH in Water
1 mL 2% HCOOH in MeOH:H2O 45:55
Experiment for Oasis® MAX 96-Well Plate 30 mg
Acidic analyte is eluted;
more hydrophobic acidic
interferences are retained
17
Locks ionized analyte
on strong anion-exchange
sites; removes
proteins and salts
Elute:
1 mL 2% HCOOH in MeOH:H2O 90:10
Neutralizes acids;
removes more polar
acidic interferences
3B–4: Oasis® WCX 2x4 Method—Optimized for Strong Bases
When the greatest selectivity and sensitivity for strong bases such as quaternary
amines [pKa >10] is required to achieve the lowest limits of detection [LOD] and
quantitation [LOQ], optimization of Protocol 2 is recommended. As an example,
a wash-elute study was performed to determine the optimal retention and elution
parameters for valethamate on Oasis® WCX [below left]. These experimental
data were then used to optimize a selective Oasis® WCX SPE method [below
right] to remove neutral, acidic, and basic interferences.
Wash-Elute Study
Optimized Oasis® WCX Method for Valethamate
O
[% MeOH in water] : [conc. HCOOH] 98:2 v/v
10%
20%
30%
40%
50%
60%
70%
80%
90%
O
N+
Br–
100%
Valethamate
Condition/Equilibrate:
1 mL MeOH/H2O
Load sample:
Indicates Peak Area
of Analyte in LC Analysis
of Eluate
1 mL plasma or urine
Maximum
% Organic Wash
Minimum
% Organic Elute
Wash 1:
1 mL 5% NH4OH
0
10
20
30
40
50
60
70
80
90
Removes interfering
acids [ionized] and neutral
compounds [including
unionized bases]
100
% MeOH in Water
Experiment for Oasis® WCX 96-Well Plate 30 mg
Wash 2:
1 mL 100% MeOH
Wash 3:
1 mL 2% HCOOH in MeOH:H2O 25:75
Strongly basic analyte is
eluted; more hydrophobic
basic interferences
are retained
Ionizes weak cationexchange sites to lock on
analytes; removes
proteins and salts
Neutralizes cationexchange sites; removes
more polar strongly
basic interferences
Elute:
1 mL 2% HCOOH in MeOH:H2O 75:25
3C: Oasis® HLB Generic Method
In 1996 Waters introduced Oasis® HLB, the first hydrophilic-lipophilic-balanced
polymeric SPE sorbent. By careful design of its chemical structure and particle
morphology [see page 4], we dramatically elevated the performance of SPE.
• Its higher retention power [3–5x] reduces breakthrough, increases enrichment
factors, and permits finer tuning of gradient steps for more selective washing
and elution sequences. Especially hydrophobic analytes may require stronger
elution solvents. Polar compounds like phenols [> 9x higher k] that interact
via hydrogen bonding with the amide moieties in the HLB backbone may
require a protic solvent [e.g., methanol] rather than an aprotic solvent [e.g.,
acetonitrile] for efficient elution.
When isolating a range of acidic, basic, and neutral compounds, a generic
method using Oasis® HLB is recommended to remove unretained matrix
constituents [e.g., salts, sugars, polar lipids, proteins) while reproducibly retaining,
and subsequently eluting, a broad chromatographic polarity range of acidic, basic,
and neutral analytes.
When transferring methods from C18-bonded-silica phases, consider these three
unique advantages of Oasis® HLB:
• Its excellent stability over a pH range of 0–14 and compatibility with
a broad range of organic solvents facilitates development of rugged,
reliable methods.
• Its higher capacity [2–3x more surface area] means correspondingly less
sorbent weight is required. Bed and elution volumes can be reduced. Smallerscale-device formats are more effective.
Oasis® HLB Generic Method for Acids/Neutrals/Bases
Prepare Sample
(typically acidify)
Condition/Equilibrate:
MeOH/H2O
Load sample solution
Wash:
MeOH:H2O 5:95
Elute:
MeOH
[Optional; e.g.,
often not required in
µElution plate format]
18
Evaporate and Reconstitute
(optional)
[e.g., acidify
to disrupt drug–
protein binding]
3D: Oasis® HLB Optimized Methodology
Chemical and chromatographic principles may be applied to optimize methods on
Oasis® HLB. Selectivity is dramatically enhanced by tuning pH, as well as the ratio
of organic solvent to water, in the mobile phase to manipulate retention.
If analytes or interferences are ionizable, then, as highly polar entities in their
charged states, they may be eluted in weak mobile phases. If, by changing pH,
they are converted to neutral form, they are retained primarily by the strength of
their hydrophobic interaction with the sorbent surface. Stronger mobile phases, with
higher organic solvent concentrations, will then be required for successful elution.
Published work by Waters chemists clearly demonstrates the benefits of such
a 2-D [two-dimensional] process on Oasis® HLB. The theory of retention,
wash-elute studies for verapamil and two of its metabolites, and successive
selectivity improvements made by refining the Oasis® HLB method are
summarized in the figures below.
Theory: Retention Factor [k] vs. pH for Acids, Bases, and Neutrals
Wash-Elute Study for Verapamil and Metabolites in Plasma
40
Acid Retained
2% Acetic Acid Modified Wash
2% NH4OH Modified Wash
Base Retained
3
Acid [HA]
Retention Factor k
32
pKa = 9.0
pKa = 4.8
16
8
0
2
4
pH 8
Recommended pH range for silica
10
12
40
60
% MeOH
CN
H3CO
Low Retention for Acid
6
2
80
H
N
H3CO
0
100
Minimum
% Methanol Elution
OCH3
H3CO
OCH3
H3CO
20
N
80
100
OCH3
OCH3
2. Verapamil
CN
H3CO
Recommended pH range for Oasis® Sorbents
40
60
% MeOH
CN
1. Norverapamil
14
H3CO
0
1
Maximum
% Methanol Wash
0
20
Acid [A–]
Base [BH+]
1
0
0
Low Retention for Base
0
2
Maximum
% Methanol Wash
Neutrals
24
3
indicates
peak area of analyte
in LC analysis of eluate
Base [B]
OCH3
N
OCH3
OCH3
3. Methoxyverapamil
Effect of Method Development Optimization on Chromatography: Verapamil in Plasma
Oasis® HLB Generic Method
Modified Oasis® HLB Generic Method
Optimized Oasis® HLB Method
Prepare sample solution
[acidified to disrupt protein binding]
Prepare sample solution
[acidified to disrupt protein binding]
Prepare sample solution
[acidified to disrupt protein binding]
Condition/Equilibrate:
Condition/Equilibrate:
Condition/Equilibrate:
Load sample:
Load sample:
Load sample:
1 mL MeOH/H2O
1 mL MeOH/H2O
1 mL MeOH/H2O
1 mL plasma
1 mL plasma
1 mL plasma
Wash 1:
Wash 1:
Wash 1:
1 mL 5% MeOH
1 mL 5% MeOH with 2% acetic acid
1 mL 5% MeOH
Elute:
Wash 2:
Wash 2:
1 mL 100% MeOH
1 mL 5% MeOH with 2% NH4OH
1 mL 5% MeOH with 2% NH4OH
Wash 3:
Elute:
1 mL 65% MeOH with 2% NH4OH
1 mL 65% MeOH with 2% acetic acid
Peak
Peak
Peak
Peak
0.004 AU
Elute:
Identification:
1: Norverapamil
2: Verapamil
3: Methoxyverapamil [I.S.]
1 mL 65% MeOH with 2% acetic acid
0.004 AU
1
1
2
3
2
4
6
8
2
1
3
3
Sample
Blank
0
0.004 AU
2
10 min
Sample
Blank
0
2
4
6
19
8
10 min
Sample
Blank
0
2
4
6
8
10 min
3E: Oasis® Advanced Methodology
Waters Oasis® product family of unique, patented sorbents in flexible device
formats and our array of method development strategies simplify and streamline
traditional SPE applications. They also enable you to meet new sample preparation
challenges, no matter whether they have been recently ripped from the headlines or
previously relegated to the unsolvable SPE problem files.
Emerging Contaminants —
Oasis® WAX Method for PFOS/PFOA
Mounting evidence attests to the public health danger posed by persistent pollutants
such as perfluorooctanesulfonic acid—used in stain repellents, fire retardants, and
food packaging—and perfluorooctanoic acid—used in the manufacture of nonstick
cookware, waterproofing products and some fast-food containers. Binding to
proteins, not lipids, in human and animal tissues, these toxic, strong acids threaten
the environment and food safety.
An Oasis® WAX cartridge is the key to successful sample preparation, whether
the matrix is drinking water or animal tissue extracts. A simple modification to the
Oasis® 2x4 Method for strong acids, reducing the concentration of ammonia in the
Elute 2 step, increased the recovery of PFOS dramatically. This method requires no
strong salts or ion-pairing reagents; the final eluent is volatile and MS-compatible.
Plastic containers are used throughout, as surfactants may irreversibly bind to glass
surfaces. UPLC™/MS/MS analysis was done on an ACQUITY UPLC™ BEH
C18 column [2.1 x 50 mm, 1.7 µm]. As shown here, a combination of superior
SPE cleanup, high-resolution UPLC™ separation, and sensitive MS/MS detection
enables a quantitation limit below 100 ppt.
The U.S. EPA has entered into enforceable consent agreements with several
manufacturers, citing the extraordinary combination of persistence, bioaccumulation, and toxicity properties of these acids, estimating a half-life of
4 years for PFOS in humans. Surfactant properties of longer-chain-length
perfluorinated alkyl acids further complicate already difficult attempts to isolate and
analyze them at the lowest possible levels.
Oasis® WAX Results for Perfluorinated Acids
Oasis® WAX SPE Method
For Strong Acids
3 cc 60pKmg
a <Cartridge
1:
Use
Oasis
Modification
of® WAX
Protocol 1
CF3(CF 2) 6COOH
Perfluorooctanoic acid [PFOA]
pKa ~ 1
CF3(CF 2) 7SO3H
Perfluorooctanesulfonic acid [PFOS]
pKa < 1
Analyte concentration: 2 µg/L in well water
Protocol 1
25 mL sample, acidified to pH 3
Prepare Sample
UPLC™/MS/MS of Perfluorinated acids
Condition/Equilibrate
Load Sample
C3 = Perfluoropropanoic acid
C5 = Perfluoropentanoic acid
C4 = Perfluorobutyric acid
C6 = Perfluorohexanoic acid
C4
Wash
2% Formic Acid
C8 = Perfluorooctanoic acid [PFOA]
C9 = Perfluorononanoic acid
C5
C3
Elute 1:
100% MeOH
C7 = Perfluoroheptanoic acid
C7 PFOA
C8
C6
F F F F
F
F F F F
F F F O
C OH
F F F
C9
Elute 2:
1% NH4OH in MeOH
TIC
UPLC™/MS/MS of Perfluorinated sulfonic acids
Perfluorinated
acids
PFBS = Perfluorobutanesulfonic acid
PFBS
By simply reducing NH4OH concentration
in Elute 2 step eluent from 5% to 1%,
recovery of PFOS is dramatically improved.
PFOS = Perfluorooctanesulfonic acid [PFOS]
F F
F F F
F F
F F F
F
F F F O
S OH
F F F O
PFOS
TIC
0.2
0.6
1.0
1.4
1.8
2.2
2.6
3.0
Recovery for PFOS and PFOA is > 85%
LOQ < 0.1 µg/L
20
3.4
3.8 min
Food Safety —
Oasis® MAX Method for Sudan Red
Sudan dyes are synthetic azo dyes used as industrial colorants. Unfortunately,
unscrupulous food processors evidently have used genotoxic, carcinogenic
Sudan dyes to enhance the red color of chili-containing foods intended for human
consumption. Sudan dyes are banned as food additives by the European Union,
so limits of detection for any analytical method should be as low as possible. This,
in turn, requires highly selective sample preparation.
In the sophisticated method outlined below, an acetone extract of chili sauce is
diluted and made basic before loading it onto the Oasis® MAX cartridge. Although
initially retained by reversed-phase interaction, a 1 M NaOH wash ionizes
the phenol, thereby locking it on the strong anion-exchange sorbent. Methanol,
followed by ethyl acetate, effectively removes neutral hydrophobic interferences. The
bound ionized Sudan dyes are then neutralized and eluted with ethyl acetate/
methanol/2% formic acid. After evaporation and reconstitution in mobile phase,
LC/MS analysis is done using positive electrospray ionization. Excellent,
reproducible recoveries at 80 ppb levels and interference-free analyses are easily
obtained, as shown here. With an LOD < 2 µg/kg, this method is 10x more
sensitive than those which rely upon one-dimensional SPE schemes.
Waters chemists have executed several different SPE strategies for the LC/MS
determination of Sudan dyes in chili products, each devised to accommodate
specific matrix properties. An Oasis® MAX SPE procedure proved ideal for waterbased, non-oily matrices such as fresh chilies and chili sauces.
Oasis® MAX Results for Sudan Red Dyes in Chili Sauce
Oasis® MAX SPE Method
3 cc, 60 mg
• Phenol is neutral < pH 7,
fully ionized > pH 12
• Good retention on
Oasis® MAX at pH >12
Sudan I
N
Acetone Extraction:
N
OH
Chili products (1 g) are homogenized
and extracted with 10 mL acetone.
A 1 mL aliquot is diluted to 5 mL and
adj. to pH 11 with aq. 0.1 M NaOH.
pKa ~ 9–10
Condition/Equilibration Steps:
1: 2 mL EtOAc; 2: 2 mL MeOH;
3: 1 mL 0.1 M NaOH; 4: 2 mL H2O
Confirmatory ion 1
SRM (m/z)
277>106
Load:
5 mL of diluted acetone extract
Wash Steps:
1: 2 mL MeOH:H2O 70:30;
2: 1 mL 1 M NaOH in H2O;
3: 2 mL MeOH; 4: 1 mL EtOAc
Elute:
2 mL EtOAc:MeOH:formic acid
89:9:2
Quant ion
SRM (m/z)
277>156
Evaporate and reconstitute:
in 200 µL acetonitrile:H2O 90:10
0
Comments:
Polar phenolics such as capsaicin are not
retained strongly by ion-exchange at pH 11
and are removed with Wash 1. Wash 2
[1 M NaOH] ionizes the retained Sudan
dyes prior to Washes 3 and 4
[these remove non-polar neutrals and bases].
1
2
3
4
Results From Spiked Chili Sauce — 80 µg/kg, n = 6
Sudan
Sudan
Sudan
Sudan
21
I
II
III
IV
83%
83%
77%
75%
recovery
recovery
recovery
recovery
[9%
[1%
[3%
[4%
RSD]
RSD]
RSD]
RSD]
5 min
Orthogonal SPE Using Two Cartridges—Most Powerful Methodology
For very complex matrices, the ultimate way to optimize cleanup and isolation is
to use orthogonal separation modes [e.g., reversed phase and ion exchange] in
tandem. Individual cartridges can be connected with an adapter. By careful
planning of mobile phase compatibility and retention mode sequences, the final
eluate from the first cartridge can be loaded directly into the second cartridge.
Then, after discarding the first cartridge, the second can be washed and eluted
with appropriately scaled volumes of solvent. A larger first cartridge removes
the bulk of matrix interferences. A smaller second cartridge further concentrates
the analyte(s) and maximizes the enrichment factor.
Tandem Oasis® MAX – MCX Results
for Fluoroquinolone Antibiotics in Beef Kidney – spiked at 1 µg/kg
Chromatogram 1: Result from a single Oasis® MAX Cartridge
Ciprofloxacin
Animal tissue homogenates are complex matrices containing a host of endogenous
interferences that may overload the ion-exchange and reversed-phase capacities
of an SPE sorbent. Difficulty is further compounded when analytes, such as
fluoroquinolone antibiotics, are amphoteric. Compared to a single-cartridge
cleanup, the ability of a well-designed tandem Oasis® MAX–MCX method
to conquer such a challenge successfully is dramatic. Chromatograms at right
demonstrate the selective isolation and confident determination of ciprofloxacin
and enrofloxacin at sub-ppb levels.
Enrofloxacin
0
8
16
24 min
Chromatogram 2: Result from Tandem Oasis® MAX + MCX
N
HN
N
pKa of acid ~ 5
pKa of base ~ 8–9
N
N
OH
F
O
8
OH
O
Enrofloxacin
O
Ciprofloxacin
0
N
F
24 min
16
Tandem Oasis® MAX–MCX Method for Amphoteric Fluoroquinoline Antibiotics
Load:
5 mL of prepared sample
Wash 1:
Stage 3:
Attach MCX Cartridge
to outlet of MAX Cartridge;
Elute from MAX into MCX
Condition:
Elute & Wash:
1 mL MeOH
2 mL 0.2 N HCl in MeOH
MAX Cartridge
Condition/Equilibrate:
1 mL MeOH/1 mL 5 N NaOH;
1 mL H2O
Stage 2:
Condition
Oasis® MCX
1 cc 30 mg Cartridge
MCX Cartridge
Stage 1:
Condition, Load, and Wash
Oasis® MAX
6 cc 150 mg Cartridge
Wash 2:
MCX Cartridge
MAX Cartridge
1 mL MeOH
After NaOH treatment,
MAX retains amphoteric
analytes as anions.
Wash steps remove basic
and neutral matrix interferences.
Stage 4:
Discard MAX Cartridge;
Wash & Elute
MCX Cartridge
Wash:
2 mL of MeOH
Elute:
500µL of 10% NH4OH in MeOH
MCX Cartridge
1 mL 5% NH4OH in H2O
HCl converts
amphoteric analytes
to cations.
They elute from MAX
into lower MCX bed where
they are retained. Acidic interferences
are neutralized by HCl and washed
out of both cartridges by MeOH.
22
O
Neutralize eluate with HCOOH
and bring to 1 mL with
buffered mobile phase.
Smaller bed in 1-cc MCX
Cartridge enables elution
in a smaller volume,
increasing enrichment factor.
Ordering Information
Oasis® HLB Sample Extraction Products
Description
Oasis® MCX Sample Extraction Products (Cation Exchange)
Particle
Size
Qty.
Part No.
Oasis® HLB cartridge 1 cc/10 mg
30 µm
Oasis® HLB cartridge
1 cc/30 mg
30 µm
Oasis® HLB flangeless cartridge
1 cc/30 mg
30 µm
Oasis® HLB cartridge with Gilson ASPC™ adapter
1 cc/10 mg
30 µm
Oasis® HLB cartridge with Gilson ASPC™ adapter
1 cc/30 mg
30 µm
Oasis® HLB cartridge
3 cc/60 mg
30 µm
Oasis® HLB cartridge
3 cc/60 mg
30 µm
Oasis® HLB flangeless cartridge
3 cc/60 mg
30 µm
Oasis® HLB cartridge with Gilson ASPC™ adapter
3 cc/60 mg
30 µm
Oasis® HLB cartridge
6 cc/200 mg 30 µm
NEW Oasis® HLB
3 cc/400 mg 60 µm
NEW Oasis® HLB flangeless cartridge
3 cc/540 mg 60 µm
NEW Oasis® HLB cartridge
6 cc/150 mg 30 µm
NEW Oasis® HLB cartridge
6 cc/150 mg 60 µm
Oasis® HLB cartridge
6 cc/500 mg 60 µm
Oasis® HLB cartridge
12 cc/500 mg 60 µm
Oasis® HLB cartridge
20 cc/1 g 60 µm
Oasis® HLB cartridge
35 cc/6 g
60 µm
Oasis® HLB Plus cartridge
225 mg 60 µm
Oasis® HLB Vac RC cartridge
20 cc/30 mg 30 µm
Oasis® HLB Vac RC cartridge
20 cc/60 mg 30 µm
Oasis® HLB glass cartridge
5 cc/200 mg 60 µm
Oasis® HLB Prospekt™ 2/Symbiosis™ cartridge*
1.0 x 10 mm
30 µm
Reservoir 30 cc for Oasis® cartridges
Reservoir 60 cc for Oasis® cartridges
Reservoir adapter for 1 cc, 3 cc, 6 cc cartridges
Reservoir adapter for 12 cc, 20 cc, 35 cc cartridges
Reservoir adapter for 5 cc cartridges, Teflon® 100/box
100/box
100/box
500/box
500/box
100/box
500/box
100/box
500/box
30/box
100/box
100/box
30/box
30/box
30/box
20/box
20/box
10/box
50/box
50/box
50/box
30/box
96/box
48/box
12/box
10/box
10/box
10/pkg
186000383
WAT094225
186001879
186000988
WAT058882
WAT094226
186002002
186001880
WAT058883
WAT106202
186003849
186003852
186003365
186003379
186000115
186000116
186000117
186000118
186000132
186000382
186000381
186000683
186001196
WAT011390
WAT024659
WAT054260
WAT048160
405000934
Oasis® HLB column
2.1 x 20 mm
5 µm
Oasis® HLB column
3.0 x 20 mm
5 µm
Oasis® HLB column
3.9 x 20 mm
5 µm
Oasis® HLB cartridge column
3.9 x 20 mm 5 µm
Oasis® HLB column
4.6 x 20 mm
5 µm
Oasis® HLB column
2.1 x 20 mm
15 µm
Oasis® HLB column
3.0 x 20 mm
15 µm
Oasis® HLB column
3.9 x 20 mm
15 µm
Oasis® HLB cartridge column
3.9 x 20 mm
15 µm
Oasis® HLB column
4.6 x 20 mm
15 µm
Oasis® HLB column 2.0 x 15 mm 25 µm
Oasis® HLB column
2.1 x 20 mm
25 µm
Oasis® HLB cartridge column
2.1 x 20 mm 25 µm
Oasis® HLB column
3.0 x 20 mm
25 µm
Oasis® HLB column
3.9 x 20 mm
25 µm
Oasis® HLB column
4.6 x 20 mm
25 µm
Holder kit for 2.1 x 20 mm cartridge column
Holder kit for 3.9 x 20 mm cartridge column
Extraction column connector
Inline precolumn filter kit
Replacement filters
Replacement steel gaskets
1/pkg
1/pkg
1/pkg
1/pkg
1/pkg
1/pkg
1/pkg
1/pkg
1/pkg
1/pkg
1/pkg
1/pkg
1/pkg
1/pkg
1/pkg
1/pkg
1/pkg
1/pkg
1/pkg
1/pkg
5/pkg
1/pkg
186002034
186002037
186002040
186001413
186002043
186002035
186002038
186002041
186001414
186002044
186001792
186002036
186000706
186002039
186002042
186002045
186000262
WAT046910
WAT082745
WAT084560
WAT005139
WAT084567
Oasis® HLB µElution plate
Oasis® HLB plate
Oasis® HLB plate
Oasis® HLB plate
Oasis® HLB plate
1/pkg 186001828BA
1/pkg 186000309
1/pkg 186000128
1/pkg WAT058951
1/pkg 186000679
96-well
5 mg/96-well
10 mg/96-well
30 mg/96-well
60 mg/96-well
30 µm
30 µm
30 µm
30 µm
60 µm
* For use with Spark Holland Prospekt™ 2 and Symbiosis™ systems
23
Description
Particle
Size
Qty.
Oasis® MCX cartridge Oasis® MCX flangeless cartridge
Oasis® MCX cartridge
Oasis® MCX cartridge
Oasis® MCX flangeless cartridge
Oasis® MCX cartridge
Oasis® MCX cartridge
Oasis® MCX cartridge
Oasis® MCX cartridge
Oasis® MCX cartridge
Oasis® MCX cartridge
NEW Oasis® MCX Plus cartridge
Oasis® MCX Vac RC cartridge
Oasis® MCX Vac RC cartridge
Oasis® MCX Prospekt™ 2/Symbiosis™ cartridge*
1 cc/30 mg
1 cc/30 mg
1 cc/60 mg
3 cc/60 mg
3 cc/60 mg
3 cc/60 mg
6 cc/150 mg 6 cc/150 mg
6 cc/500 mg
20 cc/1 g
35 cc/6 g
225 mg 20 cc/60 mg
20 cc/60 mg
10 x 1 mm
30 µm
30 µm
60 µm
30 µm
30 µm
60 µm
30 µm
60 µm
60 µm
60 µm
60 µm
60 µm
30 µm
60 µm
30 µm
100/box
100/box
100/box
100/box
100/box
100/box
30/box
30/box
30/box
20/box
10/box
50/box
50/box
50/box
96/box
186000252
186001881
186000782
186000254
186001882
186000253
186000256
186000255
186000776
186000777
186000778
186003516
186000261
186000380
186002098
Oasis® MCX direct connect column
Oasis® MCX column
Oasis® MCX cartridge column
Oasis® MCX column
Oasis® MCX column
Oasis® MCX column
2.1 x 15 mm
2.1 x 20 mm
2.1 x 20 mm
3.0 x 20 mm
3.9 x 20 mm
4.6 x 20 mm
30 µm
30 µm
30 µm
30 µm
30 µm
30 µm
1/pkg
1/pkg
1/pkg
1/pkg
1/pkg
1/pkg
186002050
186002046
186002051
186002047
186002048
186002049
Oasis® MCX µElution plate
Oasis® MCX plate
Oasis® MCX plate
Oasis® MCX plate Oasis® MCX plate
96-well
10 mg/96-well
30 mg/96-well
30 mg/96-well
60 mg/96-well
30 µm
30 µm
30 µm
60 µm
60 µm
1/pkg 186001830BA
1/pkg 186000259
1/pkg 186000248
1/pkg 186000250
1/pkg 186000678
Part No.
Ordering Information
Oasis® MAX Sample Extraction Products (Anion Exchange)
Oasis® WCX Sample Extraction Products
(Weak Cation Exchange)
Description
Particle
Size
Oasis® MAX cartridge Oasis® MAX flangeless cartridge
1 cc/30 mg
1 cc/30 mg
30 µm
30 µm
100/box 186000366
100/box 186001883
Oasis® MAX cartridge Oasis® MAX cartridge Oasis® MAX flangeless cartridge
Oasis® MAX cartridge Oasis® MAX cartridge Oasis® MAX cartridge
NEW Oasis® MAX Plus cartridge
Oasis® MAX Vac RC cartridge
Oasis® MAX Vac RC cartridge
Oasis® MAX Vac RC cartridge
Oasis® MAX Prospekt™ 2/Symbiosis™ cartridge*
Oasis® MAX direct connect column
Oasis® MAX column
Oasis® MAX cartridge column
Oasis® MAX column
Oasis® MAX column
Oasis® MAX column
3 cc/60 mg
3 cc/60 mg
3 cc/60 mg
6 cc/150 mg 6 cc/150 mg
6 cc/500 mg
225 mg 20 cc/30 mg
20 cc/60 mg
20 cc/60 mg
10 x 1 mm
30 µm
60 µm
60 µm
30 µm
60 µm
60 µm
60 µm
30 µm
30 µm
60 µm
30 µm
100/box
100/box
100/box
30/box
30/box
30/box
50/box
50/box
50/box
50/box
96/box
186000367
186000368
186001884
186000369
186000370
186000865
186003517
186000372
186000371
186000378
186002099
2.1 x 15 mm
2.1 x 20 mm
2.1 x 20 mm
3.0 x 20 mm
3.9 x 20 mm
4.6 x 20 mm
30 µm
30 µm
30 µm
30 µm
30 µm
30 µm
1/pkg
1/pkg
1/pkg
1/pkg
1/pkg
1/pkg
186002056
186002052
186002057
186002053
186002054
186002055
Oasis® MAX µElution plate
Oasis® MAX plate
Oasis® MAX plate
Oasis® MAX plate
Oasis® MAX plate
96-well
10 mg/96-well 30 µm
30 mg/96-well 30 µm
60 mg/96-well 30 µm
60 mg/96-well 60 µm
1/pkg
1/pkg
1/pkg
1/pkg
1/pkg
186001829
186000375
186000373
186001256
186001205
Qty.
Part No.
Description
Particle
Size
Qty.
Oasis® WCX 1 cc cartridge
30 mg
Oasis® WCX 3 cc cartridge 60 mg
Oasis® WCX 6 cc cartridge 150 mg
Oasis® WCX 1 cc cartridge 30 mg
Oasis® WCX 3 cc cartridge 60 mg
NEW Oasis® WCX Plus cartridge 225 mg Oasis® WCX µElution plate
96-well
Oasis® WCX 96-well plate 10 mg/96-well
Oasis® WCX 96-well plate 30 mg/96-well
NEW Oasis® WCX Prospekt™ 2/Symbiosis™ cartridge* 1.0 x 10 mm
30 µm
30 µm
30 µm
60 µm
60 µm
60 µm
30 µm
30 µm
30 µm
30 µm
100/box 100/box
30/box
100/box
100/box
50/box
1/pkg
1/pkg
1/pkg
96/box
Oasis® WCX 2.1 x 20 mm column
Oasis® WCX 3.9 x 20 mm column Oasis® WCX 2.1 x 20 mm column Oasis® WCX 3.9 x 20 mm column 30 µm
30 µm
5 µm
5 µm
Part No.
186002494
186002495
186002498
186002496
186002497
186003518
186002499
186002501
186002503
186002892
186002505
186002507
186002510
186002512
Oasis® WAX Sample Extraction Products
(Weak Anion Exchange)
* For use with Spark Holland Prospekt™ 2 and Symbiosis™ systems
Description
Particle
Size
Qty.
Oasis® WAX 1 cc cartridge 30 mg
Oasis® WAX 3 cc cartridge 60 mg
Oasis® WAX 6 cc cartridge 150 mg
Oasis® WAX 1 cc cartridge 30 mg
Oasis® WAX 3 cc cartridge 60 mg
NEW Oasis® WAX Plus cartridge
225 mg Oasis® WAX µElution plate
96-well
Oasis® WAX 96-well plate 10 mg/96-well
Oasis® WAX 96-well plate 30 mg/96-well
NEW Oasis® WAX Prospekt™ 2/Symbiosis™ cartridge* 1.0 x 10 mm
30 µm
30 µm
30 µm
60 µm
60 µm
60 µm
30 µm
30 µm
30 µm
30 µm
100/box 100/box
30/box
100/box
100/box
50/box
1/pkg
1/pkg
1/pkg
96/box
Oasis® WAX 2.1 x 20 mm column Oasis® WAX 3.9 x 20 mm column Oasis® WAX 2.1 x 20 mm column Oasis® WAX 3.9 x 20 mm column 30 µm 30 µm
5 µm
5 µm
Part No.
186002489
186002490
186002493
186002491
186002492
186003519
186002500
186002502
186002504
186002893
186002508
186002509
186002511
186002513
NEW Oasis® Method Development Kits
Description
Particle
Size
NEW Oasis® sorbent selection plate
96-well
30 µm 186003249
1 cc/30 mg
30 µm 186003463
3 rows each MCX, MAX, WCX, WAX
NEW Oasis® sorbent selection cartridge kit
10 each MCX, MAX, WCX, WAX
24
Part No.
Manifold for Extraction Plate
Description
Manifold for Extraction Cartridges
Qty
Extraction plate manifold for Oasis 96-well plates
1/box
Extraction plate manifold kit A
(includes extraction plate manifold, reservoir tray,
sealing cap and 350 µL sample collection plate)
Extraction plate manifold kit B
(as kit A, with 1 mL sample collection plate)
Extraction plate manifold kit C
(as kit A, with 2 mL sample collection plate)
Oasis® 96-well µElution Plate
(Requires Manifold Spacer)
Spacer for µElution
Plate (Included
with Manifold Kit)
Collection
Plate
Part No.
Description
186001831
WAT097944
Part No.
Waters extraction manifold, 20-position without rack
(includes 20 needle tips, 25 plugs, and ejector tool)
Waters extraction manifold, 20-position
(complete with rack for 13 x 75 mm tubes)
Waters extraction manifold, 20-position
(complete with rack for 13 x 100 mm tubes)
Waters extraction manifold, 20-position
(complete with rack for 16 x 75 mm tubes)
Waters extraction manifold, 20-position
(complete with rack for 16 x 100 mm tubes)
WAT097945
WAT097946
WAT200677
WAT200606
WAT200607
WAT200608
WAT200609
Oasis® 96-well Plate
(No Spacer Required)
Extraction Plate
Manifold
186001831
Waters Extraction Manifold
Accessories for Extraction Plate Manifold
Description
Accessories for Extraction Columns and Cartridges
Qty
Disposable reservoir tray
25/box
Sample collection plate, 350 µL
50/box
Sample collection plate, 2 mL
50/box
Sealing cap for 96-well collection plate
50/pkg
SPE vacuum pump 115 V 60 Hz
SPE vacuum pump 240 V 50 Hz
NEW Vacuum box gasket kit
Kit includes:
2 foam top gaskets
2 orange O-rings
Description
Part No.
Qty
Holder kit for 2.1 x 20 mm cartridge column
1/pkg
Holder kit for 3.9 x 20 mm cartridge column
1/pkg
Extraction column connector
1/pkg
Inline precolumn filter kit
1/pkg
Replacement filters
5/pkg
Replacement steel gaskets
1/pkg
SPE vacuum pump 115 V 60 Hz
SPE vacuum pump 240 V 50 Hz
Reservoir, 30 cc (for Oasis® Plus, Light, Vac & Classic cartridges)
48/pkg
Reservoir, 60 cc (for Oasis® Plus, Light & Vac cartridges)
12/pkg
Adapter, male-male Luer (for Oasis® Classic cartridges)
100/pkg
Adapter (to attach reservoir to 1, 3 & 6 cc Oasis® Vac cartridges)
12/pkg
Adapter (to attach reservoir to 12, 20 & 35 cc Oasis® Vac cartridges)
10/pkg
WAT058942
WAT058943
WAT058958
WAT058959
725000417
725000418
186003522
25
Part No.
186000262
WAT046910
WAT082745
WAT084560
WAT005139
WAT084567
725000417
725000418
WAT011390
WAT024659
WAT024310
WAT054260
WAT048160
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©2006 Waters Corporation. Waters, Oasis, XTerra, Atlantis and Symmetry are registered trademarks of
Waters Corporation. Quattro Premier, ACQUITY UPLC, MassLynx, Sentry, SunFire, XBridge, Sirocco and
UPLC are trademarks of Waters Corporation. Prospekt and Symbiosis are trademarks of Spark Holland.
Teflon is a trademark of DuPont. All trademarks used are acknowledged. All rights reserved.
720001692EN, 06/06