Flow-injection analysis in the capillary format using electroosmotic pumping

✍ Scribed by Shaoring Liu; Purnendu K. Dasgupta

• Publisher: Elsevier Science
• Year: 1992
• Tongue: English
• Weight: 580 KB
• Volume: 268
• Category: Article
• ISSN: 0003-2670
• DOI: 10.1016/0003-2670(92)85243-y

✦ Synopsis

AbStlWt

Electroosmotlc flow induced by an electric field m a 75Frn bore fused-silica capillary IS used as the pumping mechanism for flow-mJectlon analysis (FIA) InJection of a sample mto a reagent stream contammg a tamer electrolyte or sequential mJectlon of contiguous reagent, sample and reagent segments mto a carrier electrolyte are accomplished hydrostatically Colorlmetnc detection IS performed by an optical absorbance detector using the diameter of the capillary as the optical path Typical peak area precrslon IS better than 3% m relatrve standard deviation for sample volumes I 20 nl The potential of capillary format electroosmotlcally driven FIA and related techniques IS discussed Keywords Flow mjectlon, Electroosmotlc pumping TissJen [l] was the first to calculate the consequences of downscalmg the radms of a contmuous flow analysis system from the mllhmeter to the micrometer regime and further pomt out the advantages Hungerford [2] has subsequently examined m detail the consequences of such mmlaturuatlon for a short narrow and straight channel, Hu-schfeldt IS credited with the ongmal concept [3] Subsequently Van der Linden [41 enumerated on the theoretical lrmltatlons of ultrammlaturlzatlon

In their acclaimed treatise on flow-mJectlon analysis (FIA) [3], Ruzlcka and Hansen credit Oleslk et al [5] for the fn-st "supermmlatunzed" FIA system These authors used a 250-pm bore s&a capillary and an Infrared absorption detection of 2-~1 volume m a medium of supercrltlcal CO, as the carrier fluid The system studied did not involve a sample-reagent