Determination of chromium(III) and total chromium in water by derivative atomic absorption spectrometry using flow injection on-line preconcentration with a double microcolumn.
A rapid and sensitive method has been proposed for the sequential determination of chromium(III) and total chromium in water samples by flame atomic absorption spectrometry combined with a flow injection on-line preconcentration on a double-microcolumn. The chromium(III) and total chromium in samples were retained on a double-microcolumn with a cation exchange resin, respectively, and eluted directly into a nebulizer by 3 mol L(-1) HNO3. The characteristic concentration (gives a derivative absorbance of 0.0044) and the detection limit (3sigma) for chromium were 0.512 microg L(-1) and 0.647 microg L(-1) for a preconcentration time of 1 min, respectively. This is an improvement of 20 and 14-times than those of conventional FI-FAAS. The proposed method allows the determination of chromium in the range of 0-90 microg L(-1) with a relative standard deviation of 3.63% at the 10 microg L(-1) level. The method has been applied for the analysis of chromium in reference water of National Research Center for Certified Reference Materials (GBW08607) and other water samples with satisfactory results.
Sun
Han-wen
HW
College of Chemistry and Environmental Science, Hebei University, Baoding, 071002, China. hanwen@mail.hbu.edu.cn
Kang
Wei-jun
WJ
Liang
Shu-xuan
SX
Ha
Jing
J
Shen
Shi-gang
SG