Development of a new solid phase extraction method for determination of some organophosphorous pesticides with GC-MS in surface waters

In this study, a new solid phase extraction method has been developed for the determination of some organophosphorus pesticides in surface waters by gas chromatography-mass spectrometry (GC-MS). Microspheres were prepared by suspension polymerization technique and characterized by scanning electron microscopy (SEM), infrared spectroscopy (FTIR), elemental analysis, swelling test and Brunauer-Emmett-Teller (BET) nitrogen isotherm method. Methacryloyl-amidotriptophane methyl ester (MATrp) was used as functional monomer, divinylbenzene (DVB) as crosslinker and 2,2-azobis (isobutyronitrile) (AIBN) as initiator. Solid phase extraction (SPE) cartridges were prepared with synthesized microspheres. By using the prepared adsorbent as a solid phase extraction material, the developed method was optimized. Chemometric surface response system and central composite design were used to optimize SPE conditions. Desirability factor (D) was used for the simultaneous determination of 11 organophosphorus pesticides by GC-MS. In the study, LOD values were found in the range of 0.002-0.597 μg / L for 11 organophosphorus pesticides. Correlation coefficient values were in the range of 0.987-0.999, and percent relative standard deviation (RSD) data were between 0.69-4.27% for intraday studies and 0.60-4.94% for interdisciplinary studies. Comparison studies were made for SPE column and C18 column. Finally, in the application of the method to real samples, tap water and pond water samples were studied. The recovery values for pond and tap water vary between 78-125% and 79-139%, respectively.