The optimization of pyrethroid simultaneous analysis in tropical soil of Indonesian tea plantation: Preliminary study

Abstract

The preliminary study for the simultaneous analysis of five synthetic pyrethroids (lambda-cyhalothrin, permethrin, cypermethrin, fenvalerate, and deltamethrin) in tropical soil of tea plantation has been performed. The objective of this study is to perform an optimum condition for simple method development, based on green analytical chemistry. The concentrations of 0.1 μg.g-1 for all pyrethroids were evaluated using ultrasonic and microwave-assisted extraction. The quantification was performed using gas chromatography-electron capture detection (GC-ECD). Based on the experiment, the 0.5 mm soils size particles and 30 minutes sonication times were set as optimal condition for ultrasonic-assisted extraction with the best recovery yields of spiked soils were from 80 to 105 % for each pyrethroid and repeatability represent by the relative standard deviation (RSD, %) ranging of 1.1 - 4.8 %. Results were comparable with those found by microwave-assisted extraction. The result shows that the reproducibility, which is represented by recoveries obtained, ranged from 151 - 276 %, and were unacceptable because the value was beyond the specific range that was proposed by the Association of Analytical Communities (AOAC) International. The ultrasonic-assisted extraction was applicable for pyrethroids analysis in the real sample, with concentration found was 0.01 to 0.12 μg.g-1.