超高效液相色谱-串联质谱法快速测定蔬菜中7种氨基甲酸酯类农药残留

采用超高效液相色谱-串联质谱联用(UPLC-MS/MS)技术建立了同时检测蔬菜中7种氨基甲酸酯类农药多残留量的快速检测方法。样品经乙腈提取,氨基固相萃取柱净化,WatersC18超高效液相色谱柱分离,进入电喷雾串联四极杆质谱进行检测,采用多反应监测(MRM)分析,对液质分离条件和样品前处理条件进行了优化。结果表明7种氨基甲酸酯类农药在2～500μg/L范围内线性良好(r≥0.9986)。在0.005～0.01mg/kg范围内,平均加标回收率在72.4%～112.1%之间;相对标准偏差小于13%。该方法检出限范围为1.31～3.72μg/L,测定结果满足多残留农残的检测要求。     

蔬菜中农药残留的分散液相微萃取/气相色谱-质谱联用技术快速分析

建立了分散液相微萃取/气相色谱-质谱快速检测蔬菜中农药残留的新方法.对影响萃取和富集效果的因素进行了优化.在优化的实验条件下,10种目标农药的富集倍数达738 ～895倍,检出限为0.005 ～0.06 mg/kg,线性范围为0.02 ～10 mg/kg,相关系数为0.991 2 ～0.998 7,平均加标回收率为71% ～90%,相对标准偏差为3.1% ～6.9%.该方法已成功用于蔬菜中10种农药残留的测定.     

QuEChERS/超高效液相色谱-串联质谱法测定茶叶中17种氨基甲酸酯类农药及其代谢物残留

建立了检测茶叶中灭多威等17种氨基甲酸酯类农药残留的超高效液相色谱-串联质谱(UPLC-MS/MS)方法。详细讨论了加水对茶叶中氨基甲酸酯类农药提取效率的影响。茶叶样品加水后,用乙腈提取,经QuEChERS方法净化,C18色谱柱分离,三重四极杆电喷雾质谱检测,基质外标法定量。17种氨基甲酸酯类农药残留在各自质量浓度范围内线性关系良好,相关系数(R~2)均大于0. 99。方法检出限(S/N=3)为0. 001～0. 02 mg/kg,定量限(S/N=10)为0. 002～0. 05 mg/kg。在0. 05,0. 5,5. 0 mg/kg 3个添加水平下,17种农药残留平均加标回收率在82. 1%～119. 2%之间,相对标准偏差均小于8. 5%。     

蔬菜中有机磷和氨基甲酸酯类农药残留的气相色谱测定方法探讨

用气相色谱法同时测定蔬菜中的甲胺磷、乙酰甲胺磷、氧化乐果、甲拌磷、甲基对硫磷、对硫磷、毒死蜱等有机磷农残及克百威、抗蚜威等氨基甲酸酯类农残.采用丙酮-二氯甲烷(3:7 v/v)混合溶剂提取蔬菜中有机磷及氨基甲酸酯类农药残留,经中性氧化铝和活性碳净化,DB-IMS石英弹性毛细管柱分离,在氮磷检测器(NPD)上测定.同时讨论了样品前处理方法及其测定的最佳色谱参数的选择.方法对蔬菜空白样品的平均添加回收率为77%～116%,RSD为0.3%～15%.该方法简便、快速,准确,可操作性强.为其它样品的有机磷及氨基甲酸酯类农残的分析测定提供参考依据.     

液下单液滴微萃取/快速气相色谱-质谱联用法测定蔬菜中多种有机磷农药残留

建立了液下单液滴微萃取/快速气相色谱-质谱联用测定蔬菜中多种有机磷农药残留的方法,并对前处理条件进行了优化。采用液下单液滴微萃取技术对样品进行萃取和浓缩,以快速气相色谱-质谱(GCMS)分离检测,内标法定量。在优化条件下,治螟磷、甲拌磷、异稻瘟净、甲基对硫磷、皮蝇磷、马拉硫磷、毒死蜱、水胺硫磷和喹硫磷9种有机磷农药的色谱峰分离良好,相关系数均不低于0.995 8,检出限为0.32~0.91μg/kg,加标回收率为83.2%~134.5%,相对标准偏差(n=5)为3.4%~16.5%。该方法样品前处理简单,分析快速,灵敏度高,能够应用于蔬菜中这9种有机磷农药残留的检测。     

高效液相色谱-串联质谱法测定食品中20种氨基甲酸酯类农药残留

建立了食品中20种氨基甲酸酯类农药残留量的高效液相色谱-串联质谱联用(HPLC-MS/MS)测定与确证方法。20种氨基甲酸酯类农药在0.005～0.1 mg/kg范围内线性良好,相关系数为0.991 7～0.999 6;在0.005～0.025 mg/kg范围内, 20种目标物的回收率为51.2%～125.0%,相对标准偏差为1.4%～19.8%。该方法准确、灵敏、快速,可满足国际上对食品中这20种氨基甲酸酯类农药残留量的检测需要。     

凝胶渗透色谱净化超高效液相色谱-串联质谱法检测甘草及其提取物中的11种氨基甲酸酯类农药残留

建立了甘草及其提取物中11种氨基甲酸酯类农药多残留的超高效液相色谱-串联质谱(UPLC-MS/MS)分析方法。以11种氨基甲酸酯类农药为目标分析物,样品经乙腈超声提取、凝胶渗透色谱(GPC)净化后,用UPLC-MS/MS检测。以甘草及其提取物为例,分别进行了0.02、0.04和0.1 mg/kg 3个添加浓度的11种目标分析物的加标回收率实验,甘草中11种目标分析物的回收率为72.2%～94.0%,相对标准偏差为0.7%～7.8%;甘草提取物中11种目标分析物的回收率为73.8%～94.7%,相对标准偏差为1.5%～12.7%。该方法灵敏度高、准确度好,符合农药多残留检测的技术要求,适用于甘草、黄芪等中药材及其提取物中氨基甲酸酯类农药残留的检测。     

气相色谱-质谱法测定蔬菜与水果中11种三唑类农药残留

建立了蔬菜和水果中11种三唑类农药残留的气相色谱-质谱(GC - MS)测定方法.样品用乙腈均质提取,经石墨化炭黑/氨基复合柱净化,乙腈-甲苯(3:1)洗脱.洗脱液经浓缩、溶剂交换后定容,采用气相色谱-质谱的选择离子监测方式( GC - MSD/SIM)进行测定,内标法定量.方法的线性范围为0.05～5 ng,相关系数...     

土壤中多种有机磷及氨基甲酸酯类农药残留量的气相色谱-质谱法测定

建立了气相色谱-质谱法测定土壤中12种有机磷和氨基甲酸酯类农药残留分析方法。以丙酮-石油醚(4∶1,V/V)为提取剂,采用超声波提取土壤中农药残留,经弗罗里土层析柱净化,气相色谱-质谱(选择离子模式)法同时测定了土壤中多种有机磷和氨基甲酸酯类农药。该法对0.1μg/mL和0.5μg/mL两个浓度添加水平的回收率分别为70.1%~119.0%和78.1%~119.1%,相对标准偏差分别为6.30%~9.80%和5.20%~8.23%。     

中草药中有机磷及氨基甲酸酯类农药残留量的GC-MS测定

气相色谱-质谱法同时测定中草药中多种有机磷及氨基甲酸酯类农药残留量.采用V(乙腈)∶V(丙酮)＝3∶7混合溶剂微波辅助提取,弗罗里硅土和中性氧化铝层析柱净化,气相色谱-质谱(GC-MS)联用检测,农药混标在0.01～1.0 μg/mL范围内线性良好,在0.5、0.1、0.05 μg/mL 3个水平添加平均回收率分别为86.5%～110.6%、81.2%～108.3%和72.9%～122.3%,相对标准偏差分别为2.6%～8.3%、4.6%～9.7%和2.3%～10.7%.     

Regioselectivity of olefin oxidation by iodosobenzene catalyzed by metalloporphyrins : control by the catalyst

The regioselectivity of the oxidation of three monosubstituted olefins, 6-phenoxyhex-1-ene, hex-1-ene and styrene, by iodosobenzene in the presence of various Fe-, Mn- or Cr-tetraaryl-porphyrins, was studied. It was found that, besides epoxides, known products from such systems, allylic alcohols and aldehydes were formed, the latter not being derived from the corresponding epoxides. The relative importance of these reactions greatly depends upon both the metal and porphyrin constituents of the catalyst. More particularly, the competition between epoxidation and allylic hydroxylation can be efficiently controlled by non-bonded interactions between the olefin and porphyrin substituents. No hydroxylation of the aromatic rings and no oxidative dealkylation of the ether function was detected.     

Substitution of 2-phosphaindolizines by bromine and by chlorophosphines

Bromine does not add to phosphorus in a 2-phosphaindolizine 1 but substitutes its 1-position. The 1-bromo derivatives 2 are best prepared with Br₂/NEt₃ or N-bromosuccinimide. Their hydrolysis is remarkable; it involves a debromination of C-1, an oxidation of P and a selective opening of the P/C-3 bond. PCl₃ also causes a substitution of the 1-position. The resulting 1-dichlorophosphino derivatives 5 easily undergo a substituent exchange at the exocyclic phosphorus. More 1-phosphino derivatives are formed in the reaction of 1 with phenyl and diazaphospholyl dichlorophosphine.     

Optimal acidity of complexes by solution of polynomials and by iteration

The methods for optimal acidity of complexes M(x)L(y)(OH)(m)H(n) based on direct iteration or solution of polynomials are described and discussed. Then, by a direct straightforward method of computation (that does not require any iteration) the complexes M(x)L(OH)(m)H(n) and ML(y)(OH)(m)H(n) are treated (where 1 x 3 and 1 y 3). Finally, the conditions leading to formation of polynuclear complexes are shown and discussed. The importance of study of polynuclear complexes for solving of biochemical problems is pointed out. Practical examples are given for each method.     

Synthesis of arylaliphatic chlorosilanes by alkylation of aromatic compounds by alkenylchlorosilanes

Conclusions In combination with HCl or H₂O, EtAlCl₂ is an active catalyst for alkylation of aromatic compounds by alkenylchlorosilanes, and compounds of boron, titanium, and tin are inactive in this reaction.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 7, pp. 1639–1641, July, 1985.