2014 Volume 39 Issue 1 Pages 29-35
Eighty apple samples with protected geographical indication (PGI) or designation of origin (PDO) were analyzed for 51 target pesticides using the “quick, easy, cheap, effective, rugged and safe” (QuEChERS) method. Accuracy and precision were evaluated by means of recovery experiments at four concentration levels (10–250 µg/kg). Twelve pesticide residues were detected in 75 positive samples with an average number of detected pesticides per sample equal to 6.0. The highest detection rates were observed for chlorpyrifos (n=75), quinalphos (n=75) and parathion (n=73). Only 2 of the 80 investigated samples contained pesticide residues (parathion-methyl) in levels exceeding the maximum residue limits (MRLs). According to Spearman correlation analysis, the most powerful correlations were obtained between α-endosulfan and β-endosulfan (r=0.823) and between flufenoxuron and penconazole (r=0.683). Principal component analysis revealed similarities in the pesticides levels of all PDO/PGI samples, while the kind of product also significantly impacts its residue content.