Isotachophoretic Separations on a Microchip. Normal Raman Spectroscopy Detection
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-μm-wide and 75-μm-deep separation channels are chemically etched in a serpentine design to 21-cm total length. A 120-μm-thic...
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Published in | Analytical chemistry (Washington) Vol. 70; no. 18; pp. 3766 - 3769 |
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Main Authors | , , , |
Format | Journal Article |
Language | English |
Published |
Washington, DC
American Chemical Society
15.09.1998
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Subjects | |
Online Access | Get full text |
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Summary: | 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-μm-wide and 75-μm-deep separation channels are chemically etched in a serpentine design to 21-cm total length. A 120-μm-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 NdYVO4 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 × 10-7 M (60 ppb paraquat/80 ppb diquat) are presented. |
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Bibliography: | istex:EABCCD97AC779D49FD6B61E91A70BBEE2E229C0B ark:/67375/TPS-38LT1MWM-4 |
ISSN: | 0003-2700 1520-6882 |
DOI: | 10.1021/ac980195h |