固相萃取-气相色谱法测定农产品中嘧霉胺的残留量

建立了青菜、大米、草莓、葡萄和西红柿等样品嘧霉胺残留量的SPE-GC测定方法。样品经乙腈提取,液-液分配和SPE净化,用气相色谱分法(NPD)检测器,外标法定量。实验结果:添加浓度在0.1～2.5mg/kg之间,测得其回收率为83.44%～108.82%之间,方法的检出限为0.05mg/L,同一样品中5次测定嘧霉胺残留量的相对标准偏差小于5%。     

改良QuEChERS法结合气相色谱串联质谱测定果蔬中20种杀菌剂

目的 建立果蔬中20种杀菌剂(三环唑、五氯硝基苯、嘧霉胺、乙烯菌核利、百菌清、三唑酮、戊菌唑、腐霉利、三唑醇、多效唑、稻瘟灵、抑霉唑、咯菌腈、氟硅唑、腈菌唑、肟菌酯、丙环唑、咪鲜胺、腈苯唑、苯醚甲环唑)残留量的QuEChERS-GC/MS快速测定方法。方法 以生菜、毛瓜、葡萄、李子为原料, 样品经乙腈提取, PSA粉50.0 mg、Al2O3粉50.0 mg和NH2粉30.0 mg除杂净化后, 用GC/MS外标法定量。结果 三环唑等20种杀菌剂在0.025~0.250 mg/L的质量浓度范围内线性关系良好, 相关系数为0.9974~1.0000。添加水平为0.05、0.1、0.2 mg/kg时, 除百菌清外, 其余19种杀菌剂平均回收率范围均处于83%~112%之间, 相对标准偏差(RSD)小于11.0%, 方法的检出限(LOD)为0.2~11.8 μg/kg之间。结论 本方法具有灵敏、快速、简便等特点, 能满足果蔬中三环唑等20种农药杀菌剂的检测要求。     

种衣剂中噻菌灵、粉唑醇和抑霉唑的RP-HPLC法快速分析

[目的]提出反相高效液相色谱法快速分析种衣剂中噻菌灵、粉唑醇和抑霉唑含量的方法。[方法]选用美国Angilent 1260高效液相色谱仪(配备瑞典Kromasil 100-5-C18不锈钢色谱柱),以反相高效液相色谱法测定种衣剂中噻菌灵、粉唑醇和抑霉唑含量,流动相:甲醇-水溶液,梯度洗脱;流速1.0 mL/min;柱温35℃;210 nm的检测波长;进样体积20滋L。[结果]在2.5~500 mg/L的范围内噻菌灵、粉唑醇和抑霉唑线性关系良好,平均回收率为101.17%、100.28%和101.21%,噻菌灵的RSD为0.0097%,粉唑醇的RSD为0.0230%,抑霉唑的RSD为0.0167%。[结论]该方法能准确、快速测定种衣剂中噻菌灵、粉唑醇和抑霉唑的含量。     

优化QuEChERS方法测定上海青中的霜脲氰、嘧霉胺、乙嘧酚、乙霉威

QuEChERS在近几年中的食品、环境水和土壤污染的领域广泛应用,该测试方法可以作为一种低成本、速度快的测试方法应用于杀菌剂残留问题。本文建立一种用超高效液相色谱-串联质谱法测定上海青中杀菌剂霜脲氰、嘧霉胺、乙嘧酚、乙霉威含量的方法。上海青样品经20mL乙腈的预处理方法提取后,再以150mg的乙二胺-N-丙基硅烷(PSA)和45mg的石墨化炭黑(GCB)作为固相萃取吸附剂,随后加入90mg无水硫酸镁,涡旋过有机滤膜后上机测试。上海青中霜脲氰、嘧霉胺、乙嘧酚、乙霉威的质量浓度与相应的峰面积间呈现良好的线性发展关系,霜脲氰、嘧霉胺、乙嘧酚、乙霉威残留的平均有效回收率实验均在81%～96%之间,相对标准偏差在2.4%～5.8%之间。验证该方法低成本、速度快,适合于上海青蔬菜中霜脲氰、嘧霉胺、乙嘧酚、乙霉威残量的同时检测。     

固相萃取-反相高效液相色谱法测定红毛丹中抑霉唑的残留动态

建立固相萃取-反相高效液相色谱法测定红毛丹中抑霉唑的残留动态分析的方法。色谱柱为Shim-pack VP-ODS(150mm×4.6mm,5μm),检测波长229nm,流动相为甲醇-离子对溶液(75:25,V/V),流速0.85mL/min,进样量20μL。抑霉唑在15.0～960.0μg/L(r＝0.9994)范围内与峰面积呈良好线性关系,检出限为5μg/L,抑霉唑回收率为86.4%～104.5%,相对标准偏差0.84%～2.87%。同时,还对抑霉唑由红毛丹皮向肉的迁移,在红毛丹体上的降解动态进行分析。该方法操作简便快速,可作为红毛丹中抑霉唑含量监测的方法。     

超高效液相色谱-串联质谱法同时测定水果中10种保鲜剂残留量

建立超高效液相色谱-串联质谱法同时测定水果中咪鲜胺、多菌灵、甲基硫菌灵、噻菌灵、异菌脲、抑霉唑、苯菌灵、腐霉利、百菌清、嘧霉胺10种保鲜剂残留方法。样品用Qu ECh ERS方法处理,经Acquity UPLC BEH C18色谱柱分离,乙腈-0.1%甲酸溶液为流动相梯度洗脱,经超高效液相色谱-串联质谱仪采用电喷雾电离源多反应监测模式检测,基质匹配标准溶液外标法定量。结果表明,10种保鲜剂在各自质量浓度范围内线性良好(r0.992),在3个加标水平下,回收率为75.0%～112%,相对标准偏差(n=6)不大于9.5%。10种防腐保鲜剂的检出限(R_(SN)≥3)为0.02～1.50 μg/kg,定量限(R_(SN)≥10)为0.1～4.1 μg/kg。该方法操作简便,灵敏度高,准确可靠,适用于水果中10种保鲜剂残留量的同时测定。     

液相色谱-串联四极杆质谱法测定鸡蛋中8种三唑类农药残留量

目的建立液相色谱-串联四极杆质谱法测定鸡蛋中丙环唑、三唑酮、烯唑醇、抑霉唑、三唑醇、戊唑醇、氟硅唑和三环唑残留量的分析方法。方法取均质后的鸡蛋样品经乙腈溶液提取,加入无水硫酸镁和氯化钠进行脱水和盐析,高速离心后,取适量上层提取液经0.1%(V:V)甲酸稀释后,用中性氧化铝粉末净化并以10000 r/min离心取上清液,过0.22μm滤膜后上机测定。使用反相色谱柱进行分离,流动相为0.1%甲酸与乙腈,采用梯度程序进行洗脱,串联四极杆质谱法进行定性定量分析。结果 8种农药在2.5~250μg/kg范围内线性关系良好(r≥0.995),方法的检出限为1μg/kg,定量限为2.5μg/kg,添加回收率在78.31%~88.53%内,相对标准偏差低于10%。结论该方法具有较好的准确度与精密度,适用于鸡蛋中丙环唑、三唑酮、烯唑醇、抑霉唑、三唑醇、戊唑醇、氟硅唑和三环唑的残留量测定。     

分散固相萃取-超高效液相色谱-串联质谱法测定马铃薯中的抑芽丹

目的建立超声提取-分散固相萃取-超高效液相色谱-串联质谱(ultra performance liquid chromatography-tandem mass spectrometry,UPLC-MS/MS)法测定马铃薯中的抑芽丹。方法对样品的前处理方法及UPLC-MS/MS分析条件进行优化,样品经乙腈提取、超声、分散固相萃取净化,多反应监测模式(multiple reaction monitoring,MRM)进行测定。结果抑芽丹在0.03~50.0 mg/kg范围内均呈良好的线性关系,相关系数为0.9995;检出限(S/N=3)为0.01 mg/kg,定量限(limit of quantification,LOQ,S/N≥10)为0.03 mg/kg;在加标量为0.01、0.1、50 mg/kg下,回收率为83.7%~92.1%,相对标准偏差为0.8%~4.9%。结论该法简便、快速、结果准确可靠、灵敏度高,可消除马铃薯中复杂基质的干扰,适用于马铃薯中抑芽丹的测定。     

加拿大发布多项农残新限量标准

正3月14日,加拿大发布通报,确定野生树霉中唑草酮(carfentrazone-ethyl)最大残留限量为0.010 mg/kg;甜菜根中氟唑菌苯胺(penflufen)最大残留限量为0.010 mg/kg;蜂蜜中氟氯苯菊酯(flumethrine)最大残留限量为0.003 2 mg/kg;豆类产品中腈菌唑(Myclobutanil)最大残留     

云南省三七花、三七须根中9种杀菌剂含量监测结果分析

目的 了解云南地区三七花、三七须根中丙环唑、噁霜灵、腈菌唑、醚菌酯、腐霉利、多菌灵、嘧霉胺、苯醚甲环唑、甲霜灵9种杀菌剂污染状况。方法 按照《云南省食品安全风险监测方案》中样品采集要求, 在云南8个地区采集62个样品。按照《国家食品污染物和有害因素风险监测工作手册》对多菌灵、嘧霉胺、苯醚甲环唑、甲霜灵进行检测及国家标准GB 23200.113-2018《食品安全国家标准植物源性食品中208种农药及其代谢物残留量的测定》对丙环唑、噁霜灵、腈菌唑、醚菌酯、腐霉利进行检测。结果 9种杀菌剂中, 苯醚甲环唑、嘧霉胺、甲霜灵、多菌灵超标率较高, 分别为16.1%, 14.0%, 12.9%, 4.84%。丙环唑、噁霜灵、腐霉利超标率为3.23%, 腈菌唑、醚菌酯未超标。结论 云南地区三七花、三七须根中杀菌剂污染超标率较高, 应采取措施加以控制。     

异丙威单克隆抗体的制备及鉴定

异丙威是我国农业生产中常见的杀虫剂,在果蔬、粮食和烟草等中都有广泛应用,然而这类农药也具有较强生物毒性。为了制备异丙威单克隆抗体,以实现对农药异丙威药物的快速检测。本文以2-异丙基苯酚等为原料,合成异丙威半抗原及人工抗原,并通过免疫小鼠、细胞融合、克隆、筛选获得单克隆抗体细胞株,经腹水诱导法及辛酸-硫酸铵沉淀法制得异丙威单克隆抗体,通过间接竞争ELISA法对抗体的特异性进行鉴定。结果表明,制备的异丙威单克隆抗体检测范围为1.88~82.80 ng/m L,抗体的IC50为11.70ng/m L,最低检测限为0.54 ng/m L,抗体与克百威、西维因、涕灭威、灭多威、2-异丙基苯酚5种异丙威结构类似物均无明显交叉反应,具有高特异性,能够满足农产品中异丙威残留检测的要求。异丙威单克隆抗体的制备为异丙威快速检测产品的开发奠定了基础。     

氨基甲酸酯类农药半抗原的设计与改造

本研究设计了一种针对氨基甲酸酯类农药半抗原的通用改造,制备了涕灭威和异丙威两种人工半抗原。通过分子模拟手段和制备鼠源多克隆抗体对半抗原改造效果进行评价。结果表明,最终涕灭威抗体效价为5.84×105,对涕灭威的IC₅₀为0.225 μg/mL,对涕灭威半抗原的交叉反应率为107.14%;异丙威抗体效价为4.1×105,对异丙威的IC₅₀为0.4 μg/mL,对异丙威半抗原的交叉反应率为105.26%。经该通用改造后的半抗原可以代替目标药物用于免疫分析方法的建立。     

草莓中嘧霉胺的残留与膳食风险评估

为明确嘧霉胺在大棚草莓中的残留行为及其可能产生的膳食摄入风险,进行了规范的田间残留试验及对不同人群的膳食暴露及风险评估。结果表明:大棚条件下,嘧霉胺在草莓果实上的消解速率符合一级动力学方程,半衰期为4.28 d。400 g/L嘧霉胺悬浮剂以有效成分用量562.5 g a.i./ha和843.75 g a.i./ha施药,分别设置喷施2次和3次,施药间隔期7 d。在最后一次喷药后3、5和7 d采收的草莓中,嘧霉胺最终残留量均不超过我国规定的其在草莓中的最大残留限量值(3 mg/kg)。基于残留试验数据和日平均膳食摄入量及每日允许摄入量(ADI),计算得到我国各类人群中嘧霉胺暴露的风险商(RQ)。结果表明,喷施嘧霉胺后3~7 d内的草莓对2~4岁、18~30岁和60~70岁人群的膳食摄入风险都很低,均在可接受范围之内。     

Processing factors and variability of pyrimethanil, fenhexamid and tolylfluanid in strawberries

An HPLC-MS/MS method for the analysis of three pesticides in strawberries was developed and validated. Recoveries were measured at three spiking levels and ranged from 85 to 99% (mean recoveries). The effects of processing of strawberries ranging from rinsing to jam production were investigated for the three fungicides tolylfluanid, fenhexamid and pyrimethanil, which were applied under field conditions. Kresoxim-methyl was also applied in the field, but was not found in any of the samples investigated. The effect of parameters such as preharvest interval, dose, harvest time and observed pesticide concentration after harvest (initial concentration, mg kg^-1), were examined with respect to possible reduction of the pesticides. The results from rinsing showed that all three pesticides were reduced on average by 37% for tolylfluanid, by 34% for fenhexamid and by 19% for pyrimethanil. For tolylfluanid and fenhexamid, the initial concentration significantly affected the reduction. For fenhexamid, dose could also have a minor influence on reduction. For pyrimethanil, none of the parameters significantly influenced the reduction. For jam production, cooking significantly reduced tolylfluanid by an average of 91%. For fenhexamid and pyrimethanil, a smaller reduction was seen, 25% and 33%, respectively. The reduction of tolylfluanid and pyrimethanil was affected by the preharvest interval, while fenhexamid was affected by the initial concentration. The unit-to-unit variability of fungicide contents was also investigated and the variability factors for the three fungicides were from 1.9 to 2.8.     

基质固相分散-高效液相色谱法测定食物中痕量异丙威和溴氰菊酯

本文研究了应用基质固相分散(MSPD)处理复杂样品技术与高效液相色谱法相结合测定食物中痕量异丙威和溴氰菊酯残留物的新方法。介绍了MSPD技术进行前处理的实验条件并讨论了与传统残留分析的区别。本文将MSPD技术用于水果、粮食等食物中异丙威和溴氰菊酯残留物的高效液相色谱分析,并对定量检测条件作了详细的研究。     

Development of a liquid–liquid extraction method for the determination of pyrimethanil,metalaxyl, dichlofluanid and penconazol during the fermentative process of must by GC‐NPD

BACKGROUND: A rapid, selective and sensitive gas chromatographic method is described for the analysis of four fungicides—pyrimethanil, metalaxyl, penconazol and dichlofluanid, widely used in vineyards—in must and wine, as well as samples during alcoholic fermentation. The effect of alcoholic fermentation on pyrimethanil concentration in synthetic and real musts was studied. RESULTS: The proposed method was based on liquid–liquid extraction followed by gas chromatography with nitrogen–phosphorus detector. n‐Hexane was the most appropriate solvent for extracting the target fungicides in synthetic and real samples. Quality parameters of the proposed method presented good recovery (ca 78.3% for almost all compounds) and precision (between 1.4% and 6.1%), and quantification limits lower than maximum residue limits. However, for dichlofluanid recovery levels of well over 100% were found. CONCLUSIONS: There was no matrix effect in the analysis of pyrimethanil, metalaxyl or penconazol, but this effect was observed for dichlofluanid in synthetic and real matrices. The application of the fermentative process on pyrimethanil fungicide caused a high decrease in the concentration of this compound, and no product appeared in degradation. The decrease of pyrimethanil in fermented samples was similar in both synthetic and real samples. Copyright © 2009 Society of Chemical Industry     

一种异丙威胶体金免疫快速检测试纸条的研制

农产品的农药残留检测方法较多，异丙威作为速效性农药，应用较为广泛，但是检测异丙威的快速检测方法极少。该研究通过制备异丙威半抗原，研制出一种能够检测蔬菜、水果中异丙威的胶体金免疫层析试纸条。结果表明，该试纸条对蔬菜、水果等农产品中异丙威的最低检出限为10 μg/kg，检测时间仅为15 min，假阳性率和假阴性率均为0。与甲草胺、亚胺菌、乙霉威和异丁草胺等药物无交叉反应，技术指标均符合《农残办技术材料要求及审查程序》要求。该试纸条检测快速、便捷，能够应用到基层实验室的大批量样本检测，具有实际意义。     

Residues of azoxystrobin, fenhexamid and pyrimethanil in strawberry following field treatments and the effect of domestic washing

Residues of the pesticides azoxystrobin, fenhexamid and pyrimethanil were determined in strawberry after field treatment. The effect of 'home' washing with tap water and a commercially available vegetable detergent on residue levels was also studied. After treatment, azoxystrobin and pyrimethanil residues on strawberry were on average 0.55 and 2.98 mg kg^-1, respectively, values below the maximum residue level (MRL) fixed by the European Union (2.0 and 5 mg kg^-1, respectively), while fenhexamid residues were on average 2.99 mg kg^-1, which is very close to the MRL of 3.0 mg kg^-1, but some samples were over the MRL. Thereafter, all residues declined, with a half-life of about 8 days (azoxystrobin and fenhexamid) and 4.8 days (pyrimethanil). Washing the fruit with tap water reduced the residues of azoxystrobin and fenhexamid but did not affect pyrimethanil residues. Finally, when fruits were washed with a commercial detergent, greater amounts were removed (about 45% of azoxystrobin and pyrimethanil and 60% of fenhexamid).     

高效液相色谱法测定牛奶中速灭威、克百威、异丙威农药残留

建立了牛奶中速灭威、克百威（呋喃丹）、异丙威的高效液相色谱测定与确证方法。3种氨基甲酸酯类农药标准曲线线性关系良好;相关系数R2为0.990～0.996;检出限为6.13～7.87 μg/kg;回收率为70.4%～102.5%。该方法准确、灵敏、快速,可满足检测需要。