吡噻菌胺及其代谢物在柑橘中的残留行为及膳食风险评估

目的 建立基于超高效液相色谱-串联质谱的柑橘中吡噻菌胺及其代谢物1-甲基-3-（三氟甲基）-1H-吡唑-4-甲酰胺(1-methyl-3-trifluoromethyl-1H-pyrazole-4-carboxamide, PAM)残留分析方法，并开展残留实验，以研究吡噻菌胺及其代谢物在柑橘中的残留行为及膳食风险评估。方法 样品中残留的吡噻菌胺及PAM采用乙腈提取后，经N-丙基乙二胺和无水硫酸镁净化，超高效液相色谱-串联质谱仪检测，基质匹配外标法定量。结果 在0.0005~0.0500 mg/L范围内呈线性关系，相关系数均大于0.999；添加浓度为0.010~1.000 mg/kg时，吡噻菌胺及代谢物在柑橘中平均回收率范围分别为87%~101%和85%~106%，最大相对标准偏差为6.5%，方法定量限(limits of quantification, LOQs)均为0.010 mg/kg；以推荐剂量施药，吡噻菌胺总残留量在柑橘全果中半衰期为18.2 d；末次施药后间隔21 d采集的全果、果肉、果皮中吡噻菌胺总残留量平均值分别为0.277、0.091和0.473 mg/kg。膳食风险评估表明，吡噻菌胺在不同人群中的膳食风险概率均远小于100%。结论 该方法简便、准确、灵敏度高，可用于柑橘中吡噻菌胺及其代谢物的残留检测。最终残留量实验显示，全果、果肉、果皮中吡噻菌胺总残留量均未超过已制定的最大残留限量，对不同人群产生的膳食风险可接受。

Residues behavior and dietary risk assessment of penthiopyrad and its metabolite in Citrus reticulata Blanco

Objective To evaluate the residue behavior and dietary risks assessment of penthiopyrad and its metabolite 1-methyl-3-trifluoromethyl-1H-pyrazole-4-carboxamide (PAM) residues in Citrus reticulata Blanco, a residue analysis method of ultra performance liquid chromatography-tandem mass spectrometry was established and residual field trials were conducted. Methods Penthiopyrad and PAM in Citrus reticulata Blanco were extracted with acetonitrile, cleaned with primary secondary amine (PSA) sorbent and anhydrous magnesium sulfate, detected by UPLC-MS/MS and quantified with matrix matched external standard method. Results The correlation coefficients (r) were larger than 0.999 within the concentration of 0.0005-0.0500 mg/L, which indicated a satisfied linear relation. Meanwhile, the average recoveries of penthiopyrad and its metabolite were 87%-101% and 85%-106% with the maximum RSD of 6.5% at the spiked level of 0.010-1.000 mg/kg in Citrus reticulata Blanco, respectively. The limits of quantification (LOQs) of this method were 0.010 mg/kg for penthiopyrad and PAM. The residual dynamic experiments of Citrus reticulata Blanco treated with recommended doses showed of penthiopyrad that the half life was 18.2 d. The terminal residue experiments revealed that the mean total residues of penthiopyrad in Citrus reticulata Blanco whole fruit, pulp and peel were 0.277, 0.091 and 0.043 mg/kg respectively at the pre-harvest intervals of 21 d when applied penthiopyrad with recommended doses. The dietary risk assessment for the different populations shows that the risk probability of penthiopyrad were far below 100%. Conclusion The method is simple, accurate and sensitive, and can be used for the determination of penthiopyrad and its metabolite residues in Citrus reticulata Blanco. The results of field trials indicate that all the residues in Citrus reticulata Blanco are less than the existed maximum residue limit (MRL) of Japan and South Korea. The dietary risks posed to different populations are acceptable.