Experimental Design for the Determination of Sulfonamide Drugs in Water Using Liquid–Liquid Microextraction Combined with High Performance Liquid Chromatography

With the concept of green analytical chemistry, an experiment on the determination of sulfonamide drugs in water using liquid-liquid microextraction combined with high-performance liquid chromatography(HPLC) was designed for undergraduate experimental teaching. With a small amount of organic solvents in liquid-liquid extraction and ethanol as the green organic mobile phase for chromatographic separation, the extraction and separation conditions were optimized, and a new method of liquid-liquid microextraction combined with HPLC has been developed for determining sulfonamide drugs (sulfaguanidine (SG), sulfamethoxazole (SD), sulfamethoxazole (SDM), sulfamethoxazole (SMZ) and sulfamethoxazole (PST)) and trimethoprim (TMP, a commonly used compatible drug for sulfonamide drugs). The results indicated that the linear measurement ranges were 10−1000 μg/L for SG, SD, SDM and SMZ, 100−1000μg/L for TMP and 50−1000 μg/L for PST, respectively. The detection limits were in the ranges of 50−100 ng/L (S/N=3). The recovery rates of the lake water sample were between 93.6% and 105.2%. This experiment is based on the forefront of analytical chemistry and is moderately difficult. It is suitable as a researching experiment for senior undergraduate students majoring in chemistry, pharmacy and environment, which is beneficial for students to improve their innovation ability, low-carbon awareness and comprehensive quality.