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 (R_s) 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.

Keywords:

• passive sampling
• pesticides
• POCIS
• sampling rates

Additional information

Funding

This research project has been co-financed by the European Union (European Regional Development Fund – ERDF) and Greek national funds through the Operational Programme ‘THESSALY – MAINLAND GREECE AND EPIRUS – 2007–2013’ of the National Strategic Reference Framework (NSRF 2007–2013).