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SPE Device Formats*
In this database, icons denote the format of the Waters SPE device(s) used in the cited work. A key to the icons and brief descriptions of these formats appear below.
Waters SPE Devices are available in a variety of designs, each offering specific functional benefits. All device types, however, are filled by weight with the same high-quality sorbents. This uniformity of packing chemistry makes transfer of methods from one design to another straightforward and predictable. All cartridges and plates are sealed in special poly-foil pouches to maintain product integrity, packing activity, and purity until the package is opened. Vac and Vac RC cartridges both have integral solvent reservoirs and are principally used with vacuum manifolds and automated SPE instrumentation. Plus, Light, and Classic cartridges are the most versatile units. They attach easily to pumps and syringes for reliable, positive-pressure flow, but, if desired, can also be fitted with removable reservoirs and used on vacuum-assisted flow devices and certain automated systems. Waters patented technologies for radial compression [U.S. #4,250,035] and triaxial compression [U.S. #4,211,658] are used to form homogeneous packed beds, free of voids and channels, in Plus/Light and Classic cartridges, respectively.
Plus cartridges feature a
state-of-the-art packing process as well as a precision
design, suited to robotic applications, that also makes
manual use even more convenient. Certain sorbents are
available in short-body, and others in long-body,
configurations. Both cartridge styles are molded from
high-purity polyethylene with female-Luer inlet and
male-Luer outlet fittings. Packing materials are retained by
20-micron frits made of a blend of HD and UHMW
polyethylenes. Excellent solvent resistance and extremely
low extractable levels are important characteristics of this
design. A color-coded compression ring serves to seal the
cartridge, radially compress the packed bed, and identify
the type of sorbent. Connections can be made to different
types of devices such as positive-flow pumps and syringes,
vacuum manifolds, and some automated sample
processors. Outlet tips feature reduced
internal volume for minimal sample holdup. The fittings also
enable cartridges to be stacked in tandem: with cartridges
of the same type for increased capacity; with cartridges of
different types for sequential adsorption strategies; or
with filter units for isolation or removal of sample
particulates. Plus cartridges can be used
with liquid and gas samples and have the unique capability
for reversing flow direction, a useful feature for trace
enrichment applications. Interstitial volumes and weights of
sorbents in the short- and long-body configurations match
those of corresponding Classic cartridges. Light cartridges are the same
size and have the same features as, but about one-third the
internal volume of, the short-body Plus cartridges. A
distinctive "finned" outer body also features a color-coded
compression ring. This cartridge format allows you to scale
down your sample preparation protocols when sample size is
limited or when excessive dilution is a concern. Fractions
can be eluted in a minimal volume to improve sensitivity and
reduce solvent consumption. Classic cartridges are the
original Sep-Pak® cartridges introduced in
January, 1978. They contain the same high quality packing
materials as the other cartridge types and match the
interstitial volumes of Plus cartridges with corresponding
short (0.5 mL) and long (1 mL) bodies. This means that you
can transfer published methods developed on Classic
cartridges directly to the more versatile Plus
cartridges. Vac cartridges deliver the
option of minimum cost sample preparation. The cartridges
consist of molded, high purity polypropylene
"syringe-barrel" bodies with two polyethylene frits to
contain the packing material. A standard male-Luer tip
permits use with multi-position vacuum manifolds. Cartridge
sizes range from 1 cc to 60 cc and may contain sorbent
weights from 5 mg up to 10 g or more, respectively.
Color-coded printing on the syringe barrels identifies the
brand and sorbent. Vac RC cartridges feature an
integral 20-cc funnel-shaped reservoir and contain 10 to 500
mg of sorbent. They can be used with robotic sample
preparation equipment or with vacuum manifolds. The larger
reservoir permits convenient processing of greater volumes
of samples or solvents. This reduces set-up time and lowers
costs associated with the use of separate reservoirs.
Sorbents are identified by color-coded printing on the
cartridge bodies. Waters Oasis®
sorbents** are available in a unique, multicapacity 96-well
plate format** designed by Waters. Plates are molded from
high purity polypropylene. Wells are filled with the
same high quality sorbents and frits available in the
respective Vac cartridge formats. Fluid capacity above the
top frit in each well is approximately 2 mL. Thus, SPE
protocols developed using Oasis® cartridges
may be transferred directly to 96-well plates containing the
corresponding weight of sorbent in each well [e.g., 5,
10, or 30 mg]. SPE sample throughput using
Oasis® Extraction plates can easily keep pace
with LC/MS or GC/MS systems. * Adapted in
part from: pp 27-29 of Solid
Phase Extraction Applications Guide and Bibliography: a Resource for
Sample Preparation Methods Development,
Sixth Edition, Patrick D. McDonald, Ph.D., and Edouard S.P. Bouvier,
Ph.D., editors, 645 pp, Waters, Milford, 1995 [P/N
52853]. Access Chemical Product Information in the latest Waters Chromatography Columns & Supplies Catalog: PDF Edition
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