毛细管气相色谱法测定热不稳定有机磷农药辛硫磷

 The thermo-labile organophosphorous pesticide Phoxim was determined by capillary gas chromatographywith flame phototnetric detector. When high linear velocity H_2(>200cm/s) was used as carrier gas,the thermo-decomposition of Phoxim was considerably reduced.The most important gas chromatography conditions,injectortempereture and column head pressure,were studied.The thermo-decomposition preducts were identified by gaschromatography-mass spectrometry.     

氯甲辛三元混合制剂中甲基对硫磷和辛硫磷的分析方法研究

 介绍了用高效液相色谱一反相色谱法同时测定氯氰菊酯、甲基对硫磷和辛硫磷三元混合制剂中的甲基对硫磷和辛硫磷。采用C8反相柱,流动相为V（甲醇）：V（水）＝70：30,紫外检测波长为254nm或280nm。并与TLC－GC法测定混合制剂中的甲基对硫磷和TLC-溴化法测定混合制剂中的辛硫磷进行了比较。     

辛硫磷分子印迹聚合物修饰电极的制备及应用研究

以辛硫磷为模板分子,甲基丙烯酸(MAA)为功能单体,乙二醇二甲基丙烯酸酯(EDMA)为交联剂,偶氮二异丁腈(AIBN)为引发剂,在乙腈中沉淀聚合,研究制备了辛硫磷分子印迹聚合物(MIPs),并采用红外光谱、扫描电镜对合成的聚合物进行表征。Scatchard分析表明MIPs对辛硫磷有两种结合方式,最大表观吸附量(Qmax)和平衡解离常数(KD)分别为:Qmax1=70.58μmol/g,KD1=0.72 mmol/L;Qmax2=531.8μmol/g,KD2=7.80 mmol/L。将聚氯乙烯(PVC)5 mg和15 mg印迹聚合物超声分散于20 mL四氢呋喃(THF)中,取32μL分散液涂敷在玻碳电极上制备成辛硫磷分子印迹聚合物修饰电极,线性伏安法(LSV)检测。选择开路富集时间为5min,于0.03 mol/L HCl-0.02 mol/L KCl溶液(pH 2.2)中,辛硫磷在1.2×10-7~6.0×10-3mol/L浓度范围内,其在修饰电极上的还原峰电流与浓度的负对数呈良好的线性关系,检出限为6.0×10-8mol/L。用分子印迹聚合物修饰电极对实际样品进行分析,回收率为93.8%~96.2%。将印迹聚合物修饰电极对辛硫磷及其类似物(如三唑磷、毒死蜱、乐果等)进行检测,该电极对辛硫磷显示了良好的选择性和灵敏度。     

正相高效液相色谱法测定辛硫磷、顺式氰戊菊酯和灭多威

 eterminations of phoxim,esfenvalerate and methomyl were carried out by using normal-phase HPLC in two different mobile phase conditions with UV detector(at 254nm).The results showed that the separation of the above-mentioned compounds was satisfactory.The CV of phoxim,esfenvalerate and methomyl were 0.43%,3.05% and 0. 55% respectively.This method is simple ,rapid ,sensitive,accurate and meets the demand of quantitative analysis.     

纳米氢氧化钴原位修饰碳糊电极固-液微萃取及电化学检测辛硫磷

运用纳米氢氧化钴原位修饰碳糊电极微分脉冲伏安(DPV)法检测了辛硫磷。在外加电位下辛硫磷分子被萃取到电极表面,并与纳米氢氧化钴相互作用形成络合物,在-0.489 V处得到1还原峰,且还原峰电流随扫速线性增长,表明电极上的还原过程受吸附控制。吸附过程满足Temkin等温吸附模型。pH与电位的关系表明辛硫磷的还原过程为1电子1个质子反应。运用交流阻抗方法考察了反应过程,并辅以理论计算,表明反应为自发过程,计算结果与循环伏安法一致。采用该体系检测辛硫磷,其还原峰电流与辛硫磷浓度的对数分别在3.333×10~(-13)～3.333×10~(-8) mol/L和3.333×10~(-8)～3.333×10~(-6) mol/L范围内呈线性关系,检出限(S/N=3)可达3.333×10~(-13) mol/L。该方法具有良好的重现性及选择性,用于菠菜中辛硫磷农药的检测,结果满意。     

纳米SnSe2空心球上乙酰胆碱酯酶的固定及辛硫磷传感器的构建

描述了一种将乙酰胆碱酯酶固定在SnSe2空心球上检测辛硫磷的简单方法,用水热法合成了SnSe2空心球,并用透射电镜对其表征.固定的乙酰胆碱酯酶能保持其生物学活性,催化乙酰胆碱为胆碱,胆碱被氧化产生可检测的信号.基于辛硫磷对乙酰胆碱酯酶活性有抑制作用这个机理,在理想条件下,这种传感器对辛硫磷检测的线性范围是0.008～56μg/mL,检测限为0.004μg/mL.这种新型的传感器有很好的稳定性和重现性.这项工作表明SnSe2空心球可以作为固定乙酰胆碱酯酶的理想载体并用于构建相应的传感器.     

辛硫磷和氯氰菊酯的大口径毛细管气相色谱定量分析研究

对辛硫磷和氯氰菊酯的复配农药——２０％辛氯乳油进行了气相色谱定量分析的研究。以甲基对硫磷为内标，使用大口径毛细管柱，采用快速程序升温、高载气流速等手段，解决了辛硫磷高温易分解与氯氰菊酯色谱流出温度高的矛盾。在相同的色谱条件下对二者进行定量分析，变异系数分别为０．６７％和１．０％。方法简便、快速、准确。     

单扫描极谱法测定果、蔬中有机磷农药残留量

提出了在0．40mol/L氢氧化钠底液中对碱解后的有机磷农药进行单扫描极谱测定的方法。于起始电位－0．30V（vs SCE)进行阴极化扫描时有产生一灵敏导数波,峰电位为－0．53V（vs SCE)。并获得了辛硫磷残留量检测的最佳条件。在此条件下检测有机磷农药的线性范围分别为：辛硫磷0．12－160μg/mL,甲基对硫磷0．5－200μg/mL,水胺硫磷0．20－160μg/mL,甲胺磷0．1－1．0ng/mL,氧化乐果0．09－160μg/mL。     

A liquid chromatography–tandem mass spectrometry method to simultaneously determinate dichlorvos and phoxim in tobacco

A simple pretreatment method with liquid chromatography–tandem mass spectrometry (LC–MS/MS) was developed and validated to simultaneously determine dichlorvos and phoxim in tobacco and soil matrices. Satisfactory linearity (R² ≥ 0.9991) of the method was obtained for both analytes. The limits of detection and limits of quantification for dichlorvos and phoxim in three matrices were 0.0015–0.006 and 0.005–0.02 mg/kg, respectively. Average recoveries were 78.24–92.21% for dichlorvos and 76.62–100.51% for phoxim in soil, green tobacco leaves and cured tobacco leaves. The intra‐ and inter‐day relative standard deviations were <6%. The established method was successfully applied for the residual analysis of dichlorvos and phoxim in real soil and tobacco samples. The results indicated that the established method could be used to detect trace amounts of dichlorvos and phoxim in tobacco. The data could also help the Chinese government establish maximum residue limits of dichlorvos and phoxim on tobacco and establish proper and safe use of dichlorvos and phoxim on tobacco plants in China.     

基质固相分散-高效液相色谱法测定鲫鱼肌肉中残留的辛硫磷

建立了鲫鱼肌肉中残留的辛硫磷的基质固相分散-高效液相色谱-二极管阵列检测(MSPD-HPLC-DAD)的分析方法。通过优化样品处理条件,确定选取0.50 g鲫鱼肌肉样品与1.5 g弗罗里硅土、0.5 g无水硫酸钠混合研磨,并采用丙酮-正己烷溶液(体积比为40:60)为洗脱剂,洗脱剂用量为25 mL。优选的最佳色谱条件为：ODS色谱柱(250 mm×4.6 mm,5 μm),流动相为甲醇-水(体积比为50:50),流速0.6 mL/min,检测波长270 nm,进样量为20 μL。在上述条件下,辛硫磷质量浓度在0.01～10 mg/L范围内与响应信号呈良好的线性关系(r20.9994),检出限为3.3 μg/kg;相对标准偏差为1.1%～6.3%(n7);3个添加水平(0.05,0.1,1 mg/kg)下得到的回收率为88%～112%。该方法操作简单,耗时少,精密度高,符合农残分析的要求。