Analysis of pesticide residues in drinking water samples using solid-phase micro-extraction (SPME) coupled to a gas chromatography-electron-capture detector (GC-ECD) Prashant Chaturvedi, Rupender Kumari, Ramesh Chandra Murthy and Devendra Kumar Patel ABSTRACT The headspace solid-phase micro-extraction (HS-SPME) method with polydimethylsiloxane (PDMS, 100 μm) fiber is a cost-effective technique for the determination of different pesticide residues in environmental and biological samples followed by a gas chromatography-electron-capture detector (GC-ECD). In the present study more than 147 water samples collected in and around Lucknow city were analyzed. The method detection limits and recovery percentages were found in the ranges of 0.05–0.20 μg/L and 87.1–95.3% respectively. The average concentration of organochlorine and organophosphorus pesticides in water samples within the city were ranged between 0.258– 0.829 μg/L and 0.143–0.294 μg/L respectively. Organochlorine and organophosphorus pesticides in highway water samples ranged between 0.261–2.80 μg/L and 0.129–0.53 μg/L. Pyrethroid pesticides were not found in any of the water samples tested. The levels of pesticide residues were compared with their MRL values recommended by the Prevention of Food Adulteration Act (PFA), Government of India (1954). Prashant Chaturvedi Rupender Kumari Ramesh Chandra Murthy Devendra Kumar Patel (corresponding author) Analytical Chemistry Section, CSIR – Indian Institute of Toxicology Research (CSIR – IITR), M.G. Marg, P.O. Box 80, Lucknow 226001, Uttar Pradesh, India E-mail: dkpatel@iitr.res.in Key words | GC-ECD, headspace SPME, Lucknow, pesticides, water ABBREVIATIONS HCH hexachlorocyclohexane α alpha β beta γ gamma δ delta DDE dichlorodiphenyldichloroethylene DDD dichlorodiphenyldichloroethane DDT dichlorodiphenyltrichloroethane PDMS polydimethylsiloxane HS-SPME headspace solid-phase micro-extraction OCs organochlorines OPs organophosphorus GC-ECD electron-capture detector Ni 63 nickel 63 RPM revolutions per minute INTRODUCTION Despite the banning or restriction on the usage of organo- chlorine pesticides (OCs) in developed countries during the 1970s and 1980s, some developing countries are still using them for agricultural and public health purposes because of their low cost and versatility in controlling var- ious insects (Tanabe et al. ). Their easy availability in agricultural areas, high toxicity and the rapid action of these compounds are the main reasons for their use in suicide cases. According to an Indian Pesticide report, it is estimated that India loses approximately 18% of the crop yield (valued at Rs. 900 billion) due to pest attack each year. The consumption of pesticide per hectare is low in India at 381 g when compared with the world average of 500 g. Organophosphorous pesticides are very toxic when absorbed by human organisms because of acetyl- 754 © IWA Publishing 2011 Water Science & Technology: Water Supply | 11.6 | 2011 doi: 10.2166/ws.2011.112