A rapid determination method of residual penicillin G and its two metabolites in citrus was developed and validated by dispersive solid‐phase extraction and ultra‐high performance liquid chromatography–tandem mass spectrometry (DSPE/UPLC–MS/MS). The samples were extracted with 80% acetonitrile and purified with octadecylsilane. High linearity was obtained with correlation coefficients (r²) >0.9981. The limits of quantification were 0.005–0.01 mg/kg. The recoveries of penicillin G and its metabolites spiked in blank citrus were within 76.7–107%, with relative standard deviations of 1.3–9.6%. The dissipation dynamics and distribution of penicillin G in citrus followed first‐order kinetics, with half‐life of 1.7–2.7 days. Penicillin G degraded easily in citrus and the metabolite was mainly penilloic acid, which can exist stably for long time. The terminal residues of penicillin G in pulp, whole citrus and peels were 0.015–0.701, 0.047–7.653 and 0.162–13.376 mg/kg, respectively. The hazard indexes for risk assessment of citrus were significantly <1, suggesting that the health risks to humans after consumption of citrus were insignificant and negligible. These results could provide necessary data for evaluating the safe and proper use of penicillin G in citrus.

中文翻译：

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利用DSPE / UPLC-MS / MS在田间条件下对柑橘中青霉素G及其两种代谢产物的耗散和残留测定。

建立了一种快速测定柑橘中青霉素G及其两种代谢物含量的方法，并通过分散固相萃取和超高效液相色谱-串联质谱（DSPE / UPLC-MS / MS）进行了验证。样品用80％乙腈萃取并用十八烷基硅烷纯化。通过相关系数获得高线性度（r ²）> 0.9981。定量限为0.005-0.01 mg / kg。空白柑橘中加标的青霉素G及其代谢物的回收率在76.7–107％之内，相对标准偏差为1.3–9.6％。柑橘中青霉素G的耗散动力学和分布遵循一级动力学，半衰期为1.7-2.7天。青霉素G在柑橘中易降解，代谢产物主要为戊二酸，可长期稳定存在。纸浆，整个柑橘和果皮中青霉素G的终末残留分别为0.015-0.701、0.047-7.653和0.162-13.376 mg / kg。柑橘风险评估的危害指数显着小于1，表明食用柑橘后对人类的健康风险微不足道且可忽略不计。