Miniaturized solid-phase extraction with resin disks.
The properties and advantages of membrane disks for solid-phase extraction (SPE) are described. Miniaturization is a trend in SPE, as well as chemical analysis in general. A semimicro method is reviewed in which an extraction disk 4 mm in diameter is used for SPE. Even smaller scale separations are possible with a device in which a membrane 0.7 mm in diameter was incorporated into the needle of a 50-micro syringe. Aqueous samples containing 10 ppb of eight substituted benzenes were passed through the miniaturized-SPE syringe automatically using a single-syringe infusion pump. Elution volumes of 5 microl provided 500-fold concentrations and delivered average recoveries greater than 90% and an average relative standard deviation (RSD) of 4.6% for the analytes. Direct injection of the 5 microl eluate from the miniaturized-SPE syringe into a gas chromatograph also produced average recoveries greater than 90% and an average RSD of 6.2%.
Fritz
J S
JS
Department of Chemistry and Ames Laboratory, US Department of Energy, Iowa State University, Ames 50011, USA. kniss@ameslab.gov
Masso
J J
JJ
D001555:Benzene Derivatives / Q000032:analysis; D002623:Chemistry Techniques, Analytical / Q000295:instrumentation*; D002849:Chromatography, Gas / Q000379:methods; D002853:Chromatography, Liquid / Q000379:methods; D008904:Miniaturization; D012116:Resins, Plant
D001555:Benzene Derivatives; D012116:Resins, Plant