Headspace‐single drop microextraction with a commercial capillary electrophoresis instrument

Abstract

Automated coupling of headspace-single drop microextraction (HS-SDME) and CE has been demonstrated using a commercial CE instrument. When a drop hanging at the inlet tip of a capillary for CE is used as the acceptor phase, HS-SDME becomes a simple but powerful sample pretreatment technique for CE before injection to facilitate sample cleanup and enrichment. By combining HS-SDME with an on-line sample preconcentration technique, large volume sample stacking using an electroosmotic flow pump, the sensitivity can be improved further. The overall enrichment factors for phenolic compounds were from 1900 to 3400. HS-SDME large volume sample stacking using an electroosmotic flow pump was successfully applied to a red wine sample to obtain an LOD of 4 nM (0.8 ppb) for 2,4,6-trichlorophenol which is a precursor for 2,4,6-trichloroanisole causing the foul odor in wine called cork taint.

On-line Sample Preconcentration by Large-volume Sample Stacking with an Electroosmotic Flow Pump (LVSEP) in Microscale Electrophoresis

“…2). 38 As shown in Fig. 2d, the sensitivity could be improved with the SEFs for phenolic compounds ranging from 1900 to 3400.…”

“…The same research group exhaustively investigated the application of a polymer-coated capillary to LVSEP under the reduced EOF condition. [35][36][37][38] When a reversal potential was applied to a capillary filled with a sample dissolved in distilled water, the reduced but still existing EOF pushed the vacant SM plug out of the capillary. After SM removal, the EOF in the capillary filled with the BGS (pH 6.0) was further reduced due the increased I.…”

“…Hence, the stacked analytes switched the migration direction toward the detector. They employed several coated-capillaries, including 100% dimethyl polysiloxane (DB-1), linear polyacrylamide (LPA), cross-linking and bonding proprietary fluorocarbon polymer (μSIL-FC) and polyethylene oxide (PEO) coatings to preconcentrate and separate amino acids, 35,37 proteins, 36 weak organic acids, 37 chlorophenols 37,38 and nitrophenols 38 at pH 6.0 -11.0. As a unique application, automated coupling of headspace-single drop microextraction (HS-SDME) with LVSEP-CE was demonstrated using a commercial CE instrument.…”

Contemporary sample stacking in analytical electrophoresis

“…Park et al. described an automated coupling of headspace single‐drop microextraction and LVSS‐CE for the determination of phenolic compounds in red wine. With 400 mM borate buffer with 0.02% fluorocarbon polymer neutral at pH 9.2 as the BGE and using UV detection at 214 nm, the reached LOD was 4 nM.…”

Analyte focusing by micelle collapse for liquid extraction surface analysis coupled with capillary electrophoresis of neutral analytes on a solid surface

“…CE is usually used for analyzing liquid samples. By combining headspace extraction, CE can also be used for gaseous substances . However, the analysis of a solid sample involves homogenizing a portion of the sample and reconstituting it in an appropriate solvent, and often requires additional sample pretreatment steps .…”