Study on development of an analytical procedure to quantify glyphosate by capillary electrophoresis method and its application for beverage

Abstract

Nowadays, the issue of fresh food, drinks, and residue analysis of toxic compounds in food and drinks is increasingly interested in society. In this study, an analytical procedure for quantitative analysis of the glyphosate residue in beverages such as tea infusion and beer was developed based on the capillary electrophoresis method with capacitively-coupled contactless conductivity detector combined with sample preparation using solid phase extraction technique. The analytical conditions optimised for capillary electrophoresis equipment included: histidine/acetic acid background electrolyte solution with histidine concentration of 1 mM and pH value was adjusted to 2.75 by acetic acid; a separation voltage was 20 kV was applied and a high voltage injection at 20 kV for 10 seconds was chosen. The optimised analytical procedure has resulted in a low detection limit of glyphosate (0.42 µg/l), the repeatability and reproducibility expressed by the relative standard deviation of the peak area and migration time were both less than 10%, a wide linear range, and the obtained recovery efficiency of glyphosate on different drinks were achieved to values ranging from 88.7 to 96.3%.