Zb 5ms plus

For the GC-MS/MS analysis of studied pesticides in livestock products, GCMS-TQ8050 (Shimadzu, Kyoto, Japan) was used. The columns used in the analysis were ZB-5MS Plus (30 m × 0.25 mm, 0.25 µm, Phenomenex Inc., Torrance, CA, USA). The carrier gas was helium at a flow rate of 1.5 mL/min, and the Q2 collision gas was argon. The interface temperature was set at 300 °C for the splitless injection of 2 µL. The oven temperature was initially set at 90 °C, which was maintained for 3 min; it was then increased to 120 °C at a rate of 20 °C/min; and then increased at a rate of 8 °C/min to 300 °C and maintained for 3 min. The GC-MS/MS analytical conditions are presented in detail in Table A2.

VPs were quantitated exactly as previously described using GC–MS/MS [7 (link),10 (link),20 (link)]. In brief, a Trace 130 gas chromatograph equipped with a TSQ9000 triple quadrupole mass spectrometer (GC–MS/MS; both from Thermo Fisher Scientific; Waltham, MA, USA) was used to acquire all date in selected reaction monitoring mode. The GC column used was a Zebron ZB-5MSplus (30 m × 0.25 mm × 0.25 μm; Phenomenex; Torrence, CA, USA) and helium was used as the carrier gas (1.5 mL/min). A split ratio of 1:4 was used and 1 μL was selected as the injection volume. The GC oven and MS system parameters including all transitions were exactly as previously used [7 (link),10 (link),21 (link)]; see Figure S1Supplemental for representative extracted ion chromatograms for all analytes.