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On‐line preconcentration for capillary electrophoresis‐atomic fluorescence spectrometric determination of arsenic compounds
Author(s) -
Yin XueBo
Publication year - 2004
Publication title -
electrophoresis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.666
H-Index - 158
eISSN - 1522-2683
pISSN - 0173-0835
DOI - 10.1002/elps.200405815
Subject(s) - capillary electrophoresis , chemistry , analyte , chromatography , arsenate , arsenic , detection limit , arsenite , analytical chemistry (journal) , matrix (chemical analysis) , electrophoresis , sample preparation , organic chemistry
An on‐line preconcentration method was developed for capillary electrophoresis (CE) with hydride generation‐atomic fluorescence spectrometric (HG‐AFS) detection of arsenite, arsenate, dimethylarsenic acid, and monomethylarsenic acid. These arsenic species were negatively charged in the sample solution with high pH. When the potential was applied to the electrophoretic capillary, the negatively charged analyte ions moved faster and stacked at the boundary of sample and CE buffer with low pH. So, high sample pH in combination with low buffer pH allowed the injection of large sample volumes (∼ 1100 nL). Comparison of the preconcentration of analyte solution, prepared with doubly deionized water and that prepared with lake or river water, indicated that preconcentration was independent on the original matrix. With injection of ∼1100 nL sample, an enrichment factor of 37–50‐fold was achieved for the four species. Detection limits for the four arsenic species ranged from 5.0 to 9.3 μg·L −1 . Precisions (RSDs, n = 5) were in the range of 4.9–6.7% for migration time, 4.7–11% for peak area, and 4.3–7.1% for peak height, respectively. The recoveries of the four species in locally collected water solution spiked with 0.1 μg·mL −1 (as As) ranged from 83 to 109%.