腈吡螨酯在橙汁加工过程中的残留行为

新型杀螨剂腈吡螨酯在柑橘产业中具有良好的应用前景,但也存在一定残留风险。为明确腈吡螨酯在橙汁加工过程中的残留行为,该试验分别在重庆和湖南两地以750 mg a.i./kg(最高推荐施药剂量的5倍)对柑橘喷施30%(质量分数)腈吡螨酯悬浮剂,并进行橙汁商业化加工,使用改进的QuEChERS法结合超高效液相色谱-串联质谱分析了各加工单元的腈吡螨酯残留量。结果表明,初榨果汁、精滤果汁、非浓缩还原汁和浓缩果汁中腈吡螨酯的残留量均显著低于柑橘鲜果中的残留量,加工因子均小于1;柑橘皮渣和皮精油中腈吡螨酯的加工因子>1,表明在加工皮渣和皮精油的过程中腈吡螨酯浓度增大,并且在皮精油中富集倍数较高。研究结果可为柑橘中农药残留的加工因子数据库提供参考,有助于更准确地评估腈吡螨酯的膳食风险,助推该药在柑橘产业中的应用。

GC测定毒死蜱在苹果及其加工制品中的残留

采用田间喷药方式对苹果树喷洒毒死蜱农药，然后模拟苹果汁商业化加工过程进行加工，利用气相色谱对苹果、鲜榨苹果汁以及浓缩果汁中的毒死蜱进行检测，结果表明，果汁商业化榨汁过程可有效降低农药残留，鲜榨果汁中的农药残留仅为原料果中的0．4％～24.2％，而浓缩果汁中由于水分的流失，农药残留会出现大幅的提高。该法加标回收率为81．15％-106．02％，测定结果的相对标准偏差为7．6％～18．6％（n=5）。

Application of Hydrocracking Process for Upgrading Tail Oil Quality in 1.0 Mt/a Hydrocracker Unit at SINOPEC Yangzi Petrochemical Company

This article focuses on the hydrocracking technology for upgrading the quality of tail oil and the first commercial application of the RN-32V/RHC- 1 catalysts in the 1.0 Mt/a hydrocracker at the Yangzi Petrochemical Company, which was started up successfully in September 2008. One month after start-up of the hydrocracking unit, an evaluation opera- tion has been conducted fbr assessing the catalysts performance. The technical calibration results showed that the RN- 32V/RHC-1 catalysts had high activity, and the product yield distribution was reasonable. The hydrocracker can provide abundant feedstocks for the downstream aromatic production unit and ethylene production unit.