Laboratory calibration of twelve pesticides using polar organic chemical integrative samplers

Abstract

Passive sampling is an emerging tool for monitoring micropollutants in surface waters and enables the determination of time-weighted average (TWA) concentration over extended sampling periods. For the determination of TWA concentration, the sampling rates (Rs) for the compounds of interest are required. Laboratory calibration experiments were conducted in order to determine the sampling rates of 12 selected pesticides using Polar Organic Chemical Integrative Samplers (pest-POCIS). The experiments were performed on the basis of static renewal exposure of pest-POCIS under stirred conditions for different time intervals up to 28 days. The recoveries of target pesticides ranged between 71 % and 120 % with relative standard deviation (RSD) <18%. Detection limits (LODs) and quantification limits (LOQs) ranged between 0.5 and 6 ng L−1 and 1.6 and 19.7 ng L−1, respectively. The uptake in POCIS for the studied pesticides followed a linear pattern throughout the 28 days of exposure, except for fipronil. The calculated sampling rates ranged from 0.030 L day−1 to 0.223 L day−1. The pesticides pirimiphos methyl, clofentezine, cyprodinil, fipronil and kresoxim methyl have never been studied before in calibration experiments using pest-POCIS passive samplers. Using the described analytical procedure, trace levels (ng L−1) of the target pesticides could be determined in surface waters.