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PubMed · 9751021

Isotachophoretic separations on a microchip. Normal Raman spectroscopy detection.

P A Walker·M D Morris·M A Burns·B N Johnson
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Abstract

Isotachophoretic separations of the herbicides paraquat and diquat are performed in a glass microchip etched channel and monitored on-chip by normal Raman spectroscopy. The 40-micron-wide and 75-micron-deep separation channels are chemically etched in a serpentine design to 21-cm total length. A 120-micron-thick glass cover slip is used to seal the channels. Separation field strengths up to 380 V/cm are used. The microchip is directly coupled to a Raman microprobe. No interfacing is required. Raman spectra are generated with a 2-W, 532-nm NdY-VO4 laser and collected at 8-cm-1 resolution with a holographic transmissive spectrograph and a cryogenically cooled CCD. Data acquisition is at 2-5 spectra/s. Raman isotachopherograms of the pesticides at starting concentrations as low as 2.3 x 10(-7) M (60 ppb paraquat/80 ppb diquat) are presented.

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DiquatElectrophoresisHerbicidesIndicators and ReagentsMiniaturizationParaquatSpectrum Analysis, RamanJournal ArticleResearch Support, U.S. Gov't, P.H.S.

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P A Walker, M D Morris, M A Burns, B N Johnson. 1998-09-15. Isotachophoretic separations on a microchip. Normal Raman spectroscopy detection.. https://doi.org/10.1021/ac980195h

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