7th International Conference on Engineering and Natural Sciences (ICENS). Sarajevo, Bosnia and Herzegovina 23-27 Haziran, 2021, Sarajevo, Bosnia And Herzegovina, 23 - 27 June 2021, pp.6
The effects of washing treatments on removal rates of pesticides residues on gapes (chlorpyrifos-methyl and lambda-cyhalothrin) and peppers (acetamiprid, chlorpyrifos and formetanate hydrochloride) were investigated. For method verification study, blank grapes and pepper samples were spiked with 0.5, 1 and 5 times of MRL, and 0.1, 1.0 and 10.0 times of MRL, respectively. QuEChERS method yielded an overall-recovery of 101% (RSD= 9.31%) and 104.91% (RSD= 13.41%) for grapes and pepper , respectively. These figures were within the SANTE recovery limits (60-140%). Methods revealed that the detection limits of the all pesticides in both matrix were below the MRLs. Grapes, grown in vineyard, were sprayed with pesticides 4 times and harvested 0, 2, 4 and 7 days after the last spray. Capia peppers grown in open fields were sprayed 3 times with pesticides and harvested 0, 2, and 3 days after the last spray. Then the grapes and peppers were subjected to tap water, acetic acid and citric acid washing and ultrasonic cleaning treatments. Based on harvest times and two different washing durations, processing factors (PFs) and reduction rates were calculated for each washing treatment. In grape samples, washing treatments decreased residue levels and level of removal increased with prolonged washing durations. Removal levels also decreased with prolonged harvest durations from the last spray. The citric and acetic acid washing, and ultrasonic-cleaning methods yielded more efficient removals than tap water washing treatments. As to come pepper samples, the residues gradually decreased during washing treatments with increasing process duration. Similarly, a gradual reduction was noted with the progress of harvest times. This in turn corresponded to an increase in PF. Ultrasonic cleaning and citric acid washing were more effective than the others. Non-systemic pesticides (chlorpyrifos) were more readily removed than the systemic ones (acetamiprid). Similarly, highly soluble pesticides exhibited higher reduction.