Parallel-disposable pipette extraction (Pa-DPX) using cork as a green high-throughput method for the determination of four pesticides in environmental water samples with quantification by HPLC-DAD

This study utilized cork powder as a green alternative for extractor phase using the parallel-disposable pipette extraction (Pa-DPX) method for the determination of pesticides such as atrazine, carbofuran, diuron, and simazine from aqueous environmental samples. The separation/detection was performed by HPLC-DAD. Optimization experimental conditions was achieved through univariate and multivariate designs, resulting in the following parameters: 15 mg of cork as extractor phase, 7 extraction cycles with 7.5% (m/v) NaCl in the sample, and 10 s were fixed per extraction cycle. For the desorption step, 300 mu L of acetonitrile was used as solvent with 1 desorption cycle. The limit of detection and limit of quantification values were 7.5 mu g L-1 and 25 mu g L-1 for atrazine, carbofuran, and diuron, and 15.1 mu g L-1 and 50 mu g L-1 for simazine, respectively. Linear working range varied from 25 to 400 mu g L-1 with coefficients of determination (R2) >= 0.983. The values of intraday precision varied from 4.9 to 18.1%, and those of interday precision varied from 21.3 to 32.2%. The accuracy of the method was determined through relative recoveries and the values ranged from 63.4 to 119.9%. The water environmental samples were collected at two different locations in Florian & oacute;polis, Santa Catarina, Brazil, and showed no detectable pesticides. The method presented here stands out due to the low consumption of sample and reagents, as well as the use of a renewable and biodegradable extraction phase (cork). The method is also a high-throughput alternative, due to the use of the Pa-DPX apparatus, which allows the preparation of up to five samples simultaneously.