以甘蓝和葡萄为基质,建立QuEChERS结合气相色谱-串联质谱(GC-MS/MS)法同时测定水果、蔬菜中虫螨腈、醚菊酯、嘧菌酯、烯酰吗啉的分析方法.2种基质样品分别用乙腈提取,PSA净化,三重四极杆SRM扫描,4种农药在0.005～0.500 mg/L内呈线性,相关系数R2均大于0.995,0.01、0.02、0.10 μg/kg 3个水平的添加回收率均在89.1％～113.1％,各组分定量限为0.01 mg/kg.

建立了 QuEChERS-气相色谱-串联质谱同时测定水产品中12种拟除虫菊酯类农药的检测方法.鱼、小龙虾样品经匀浆和QuEChERS前处理后即可进行气相色谱-串联质谱检测.12种拟除虫菊酯类农药在5～200 μg/L浓度范围内线性良好,相关系数r2≥0.9992,各组分的检出限(LOD)为3 μg/kg,定量限(LOQ)为10 μg/kg,满足国家标准(GB31650-2021)限量值的分析要求.各组分在1LOQ、3LOQ、10LOQ的添加水平下,在鲫鱼、鳊鱼、草鱼和小龙虾中的回收率在81.5％～115.3％,相对标准偏差(RSD,n=3)均小于15％.本方法前处理简单高效,可用于水产品中12种拟除虫菊酯类农药的快速筛查.

建立了超高效液相色谱-四极杆/静电场轨道肼高分辨质谱快速筛查水产品鱼类样品中三种多肽类物质的分析方法.样品用1％甲酸化乙腈-水(体积比7:3)提取,无需净化,直接用C18色谱柱(100 mm×2.1 mm,1.9 μm)分离,用0.1％甲酸水溶液和乙腈为流动相进行梯度洗脱,电喷雾电离正离子模式,以SIM-dd-MS2模式扫描,以提取的保留时间和一级母离子精确质量数实现对样品的快速筛查.三种多肽类物质在相应的浓度范围内线性关系良好,R-均大于0.995,定量限(LOD)为10.0 μg/kg,平均回收率为61.3％～113.9％,相对标准偏差(RSD)为2.1％～14.3％.方法快速简单易操作,数据可靠,可用于鱼类样品的快速定性筛查和定量分析.

建立了小龙虾中去甲万古霉素、杆菌肽的高效液相色谱-串联质谱测定方法.样品经0.04 g/mL三氯乙酸乙腈沉淀蛋白,0.1％(v/v)酸化甲醇水溶液(4:6,V/V)提取,正己烷去脂,经C18(100 mm×2.1 mm,粒径1.9μm)柱分离,0.1％(v/v)甲酸水溶液-0.1％(v/v)甲酸乙腈溶液为流动相梯度洗脱,用电喷雾离子源正离子模式采集,多反应监测模式下检测,外标法定量.结果表明,去甲万古霉素在50～1000μg/L,杆菌肽在10～1000μg/L范围内呈良好线性关系,相关系数(r2)均>0.995,方法检出限分别为3.0μg/kg和0.6μg/kg,定量下限分别为10μg/kg和2.0μg/kg,在低、中、高3个水平添加下,去甲万古霉素的平均回收率为80.8％～96.7％,杆菌肽的平均回收率为99.5％～114％,RSD分别为2.2％～4.3％和1.1％～6.9％.该方法简便、快速,重现性好,可用于小龙虾中去甲万古霉素、杆菌肽的快速筛查.

通过分析我国农产品质量安全检验检测体系建设现状,总结出其中存在的问题,结合问题提出一系列完善农产品质量安全检验检测体系的措施,以期可以为相关人员提供一些有价值的参考.

A method was developed for the determination of paraquat and diquat residues in water by high performance liquid chromatography-tandem mass spectrometry with solid phase extraction.The samples were cleaned up by Cleanert PWCX solid phase extraction,separated on a HILIC column using acetonitrile-5 mmol/L ammonium acetate(pH 3.7 with formic acid) as mobile phase by gradient elution,then detected in SRM mode and quantified by external standard method with the matrixmatched calibrations.The calibration curves for paraquat and diquat showed good linearities in the concentration ranges of 10.0-200.0 μg/L and 1.0-200.0 μg/L,respectively,with correlation coefficients(r2) no less than 0.997.The average recoveries for paraquat and diquat in agricultural environmental water at spiked levels of 30-200 μg/L were in the ranges of 96.8％-125.8％ and 97.2％-118.2％,with intra-assay relative standard deviations (RSDs) of 3.0％-6.3％ and 2.9％-6.0％,and inter-assay relative standard deviations of 3.3％-8.2％ and 2.7％-7.9％,respectively.The limits of detection (LODs) and quantitation (LOQs) of the method were 5.0 μg/L and 0.3 μg/L,and 10.0 μg/L and 1.0 μg/L,respectively.The results indicated that the developed method is easy,fast and sensitive,its indicators such as the linear range,recovery,precision and detection limit could meet the requirements for residue analysis.The method is suitable for the determination of paraquat and diquat in agricultural environmental water

在种植小麦赤霉病高感品种襄麦1321的田间进行施药试验.调查5种药剂:50％多菌灵可湿性粉剂、25％氰烯菌酯悬浮剂、25％咪鲜胺乳油、70％甲基硫菌灵可湿性粉剂、30％福美双可湿性粉剂分别喷施l～4次处理对小麦赤霉病的防治效果.结果表明,施药24h内降雨对氰烯菌酯的防效影响最大;咪鲜胺防效相对较差,不同施用次数的病指防效为42.51％～64.55％;多菌灵、甲基硫菌灵和氰烯菌酯施用3～4次的处理防效较高,病指防效均达70％以上;福美双的防效随施用次数增多而提高,施用4次的处理防效也达70％以上.

Purity, clarity, germination rate and moisture content are four indicators of seed quality. No matter which of them is not up to the national standards,the seed will be clarified to unqualified seed. To ensure accurate, reliable and repeatable results of wheat germination test, we must follow the germination test procedures requested in GB/T 3543.1-1995 Inspection Regulations of Crop Seed, and use operation experiences to reduce error or failure during the germination test. Methods and steps of wheat germination test were summarized in this article.