Human health risk assessment of spiropidion and the main metabolites SYN547305 (spiropidion-enol), SYN 547435, and SYN 548430 in pistachio with UHPLC-MS/MS

This research is aimed at the analysis and risk assessment of spiropidion and the main metabolites in ripe pistachio fruit with unprocessed bark by QuEChERS-Ultra-High Performance Liquid Chromatography-tandem mass spectrometry (UHPLC-MS/MS). All validation parameters were investigated for spiropidion due to a lack of analytical standards for the metabolites. Spiropidion (SYN 546330), spiropidion-enol (SYN 547305) as major metabolite, SYN 547435 and SYN 548430 were quantified with semi-quantitative analysis in multiple reaction monitoring mode (MRM) of UHPLC-MS/MS instrument for pistachio from 2, 4, 5, 6, 7, 8, 9, 10, 11, 15 and 16 weeks after spraying spiropidion (Elestal (R)) on the pistachio orchard. Results show after spraying the main metabolite with the most concentration is spiropidion-enol. All metabolites increased to the 7th week, then reduced until the 10th week. MRL is defined for spiropidion as the sum of the initial compound and the enolic form. The residual values of these two compounds in the 15th and 16th weeks after spraying (when the pistachio fruit has ripened and become nutty) were 0.04 mg kg(-1). This value is less than the default national MRL of Iran, which is 0.05 mg kg(-1), indicating the acceptability of the spiropidion residue in the pistachio product. Results of the residue risk assessment show no evidence of human health threat for adults and children consumers.