Analytical Sciences

Abstract − Analytical Sciences, 30(7), 759 (2014).

Determination of Herbicides and Its Metabolite in Soil and Water Samples by Capillary Electrophoresis-laser Induced Fluorescence Detection Using Microwave-assisted Derivatization
Liwei CAO, Tao DENG, Siliu LIANG, Xiaofang TAN, and Jianxin MENG
Department of Chemistry, College of Life Science and Technology, Jinan University , No. 601, West Huangpu Road, Tianhe District, Guangzhou 510632, P. R. China
Methods were developed to determine glufosinate (GLUF), glyphosate (GLYP) and its metabolite, aminomethylphosphonic acid (AMPA) by capillary electrophoresis-laser induced fluorescence detection using 5-(4,6-dichlorotriazinylamino) fluorescein (DTAF) and fluorescein isothiocyanate (FITC) as the derivatizing reagents. To accelerate the labeling speed, a microwave-assisted derivatization method was adopted. The derivatizing reaction time was reduced to 180 and 150 s for DTAF and FITC, whose reaction time for conventional labeling was 50 min and 5 h, respectively. The optimum separation conditions for derivatives were as follows: a back ground electrolyte (BGE) of 30 mmol L−1 sodium tetraborate containing 15 mmol L−1 brij-35, hydrodynamic injection 15 s and a 10 kV separation voltage. Under these conditions, the LODs (S/N = 3) for DTAF derivatives were 0.32, 0.19 and 0.15 nmol L−1 for GLUF, GLYP, and AMPA, respectively. The LODs (S/N = 3) for FITC derivatives were 2.60, 3.88 and 2.42 nmol L−1 for GLUF, GLYP, and AMPA, respectively. The applicability of the developed method was demonstrated by the detection of the above herbicides and metabolite in water and soil samples.