Investigation of dicofol and endosulfan pesticide levels in Tahtalı Dam Water or drinking water

Abstract

In this study, dicofol (2,2,2-trichloro-1,1-bis (4-chlorophenyl) ethanol) and endosulfan (6,7,8,10,10 - hexachloro - 1,5,5,1,6,9,9a - hexahydro - 6,9 - methano - 2,4,3 benzadioxathiepin 3-oxide) pesticide concentration levels in Tahtalı Dam Water were investigated. Endosulfan pesticide has two forms which are -Endosulfan and Endosulfan. Dicofol and Endosulfan are both organochlorine pesticides. Both of these pesticides are widely used for agricultural purposes in Tahtalı Dam Basin. These pesticides could be carried to the Tahtalı Dam Water, and therefore their concentrations should be controlled. Another reason why these pesticides were selected was that their method of determination is not straightforward and a special determination technique has to be used. That is why these pesticides were not studied extensively for zmir area. For the determination of trace amount of above-mentioned pesticides, gas chromatography-mass spectrometry (GC-MS) was generally preferred as reported in most papers [1-3]. The GC-MS instrument in our laboratory has an Ion Trap (IT) mass analyzer. Operating in Selected Ion Storage (SIS) or Tandem mass (MS-MS) modes can increase the sensitivity and selectivity of this instrument. The matrix effect coming from the aqueous solution was eliminated by GC-SIS-MS and GC-MS-MS. Dicofol did not give stable peaks. So, Dicofol did not investigate in this study. The detection limits of the instrument are 0.083 g/L for -Endosulfan, and 0.662 g/L for -Endosulfan; therefore a preconcentration process was required because the studied concentrations are in 1-3 g/L levels for surface water and 0.1 g/L levels for drinking water. Solid Phase Extraction (SPE) method was used for sample preconcentration. Gas chromatography (GC) - Mass spectrometry (MS) and Tandem mass spectrometry (MS.MS) were employed for the identification and quantification of Dicofol, -Endosulfan, and Endosulfan pesticides. For SPE procedure ENVI-18 Disk was used, optimizing the extraction volume, pH and the salt concentration. In GC.MS.MS, the lowest detectable concentrations for the -Endosulfan and -Endosulfan were found as 0.083 ng/L and 0.662 ng/L, respectively. Recovery of -Endosulfan for SPE was 112 (0.002) % in 500 ml water samples spiked with 1 mg/L pesticides. Recovery of the Endosulfan for SPE was 132 (0.008) % in 500 ml water samples spiked with 1 mg/L pesticides.