Variation of pesticide residue levels on grapes depending on time and immersing solution

In the first part of this study, pesticide residue levels in grape and raisin samples obtained from Manisa Viticulture Research Station were investigated. 360 pesticides monitored qualitatively with GC-MS and LC-MS/MS following the QuEChERS extraction to determine the types of pesticide residues in these samples. Quantitative determination of boscalid that determined as used on grapes was carried out depending on the process before drying [drying in the sun after immersion in K2CO3 (%5 w/w) solution before drying and without immersion] and for the future time. The results obtained showed that degradation rate of the pesticide in immersed samples is higher than those of not immersed. However, the second part of the study includes the analysis of pesticide degradation rates that prepared at 3 different concentrations (2, 4 ve 6 mg/L) using water and K2CO3 solutions buffered at 5 different pH (pH=7, 8, 9, 10, 11) with boscalid standart, during 30 days to investigate the relationship between the high degradation rate of the pesticide in immersed media and the effect of alkalinity provided by K2CO3. Correlation coefficients of the calibration curves obtained ranging from 0.9947 to 0.9999 in linearity studies with prepared boscalid standart solutions (1, 2, 4, 6 ve 7 mg/L) for this purpose. Changes in the amount of pesticide was calculated with measuring the absorptions of the prepared solutions ranging from at 234.66 nm to 244.99 nm wavelenghts for the different media using UV-Vis spectrophotometer in preparation day (first day), 3nd day, 7th day, 15th day and 30th day. The results showed that boscalid degradation rate is higher in buffer media. Decreases in the amount of pesticide occured higher especially at pH=8, 9 and 10 buffers than pH=7 and 11.