Determination of 115 pesticide residues in oranges by high-performance liquid chromatography–triple-quadrupole mass spectrometry in combination with QuEChERS method

• QuEChERS LC–MS/MS method for 115 pesticides in orange matrix was validated.
• We determined the presence of pesticides in 400 orange samples from Turkey.
• Chlorpyrifos was detected in 6.25% of oranges analysed.
• The study shows that risk is not significant for orange.

The present study aims to determine 115 pesticide residues in 400 commercially available orange samples in Adana, Mersin and Hatay provinces of Turkey. Pesticide determination was carried out using liquid chromatography–tandem mass spectrometry (LC–MS/MS) method. A modified QuEChERS (quick, easy, cheap, effective, rugged, and safe) sample preparation technique involved acetonitrile-based extraction of the samples, and followed by dispersive solid-phase extraction (d-SPE) cleanup using primary–secondary amine (PSA), was used prior to LC–MS/MS analysis. The method showed satisfactory linearity, specificity, recovery and precision. The limit of detection (LOD) and limit of quantification (LOQ) for target analytes were in the range of 0.001–0.011 mg kg−1 and 0.002–0.030 mg kg−1, respectively. The expanded measurement uncertainty was not higher than 45% for all target analytes. Only one insecticide and two fungicides were detected individually in a total of 30 orange samples. Chlorpyrifos was the predominant pesticide at levels ranging from 0.01 to 0.09 mg kg−1, while imazalil was detected in 3 samples (0.09–0.48 mg kg−1) and azoxystrobin was found in only 2 samples (0.02 and 0.03 mg kg−1).