超高效液相色谱-质谱/质谱法测定叶菜中11种氨基甲酸酯农药残留

建立了采用固相萃取-超高效液相色谱-质谱/质谱法(SPE-LC-MS/MS)对叶菜中11种氨基甲酸酯农药(克百威、3羟基克百威、甲萘威、仲丁威、异丙威、抗牙威、速灭威、灭多威、涕灭威、涕灭威亚砜、涕灭威砜)残留同时测定的方法。样品用乙腈提取后经氨基固相萃取柱净化处理,经Acquity UPLCTM BEH C18(100 mm×2.1 mm,1.7μm)色谱柱分离后测定,该方法采用多反应监测(MRM)离子扫描模式,外标法进行定量,线性良好(r2>0.994),检出限为0.001～0.004 mg/kg,总体回收率为80.4%～99.8%,相对标准偏差为3.4%～10.8%。该方法的定量限满足目前国内外药物的最大残留限量要求,可作为叶菜中相关药物残留的筛选检测方法。     

The status and development of insecticide resistance in Danish populations of the housefly Musca domestica L

Samples of housefly (Musca domestica) field populations were collected from Danish livestock farms in 1997. The tolerance of the first‐generation offspring was determined for a number of insecticides. Dose‐response values were obtained by topical application for the pyrethroids bioresmethrin and pyrethrum, both synergised with piperonyl butoxide, and the organophosphate dimethoate. The organophosphates azamethiphos and propetamphos and the carbamate methomyl were tested in discriminating dose feeding bioassays. Resistance was low to moderate in most of the populations for most of the compounds tested, but this study also revealed the existence of high resistance to pyrethroid, organophosphate and carbamate insecticides in some populations. The resistance factors at LD₅₀ for bioresmethrin/piperonyl butoxide ranged between 2 and 98, and for pyrethrum/piperonyl butoxide between 2 and 29. Our results indicate that pyrethroid resistance in Denmark is increasing, since four of the 21 farms showed more than 100‐fold resistance at LD₉₅, a level of resistance only observed once before. Resistance factors at LD₅₀ for dimethoate ranged from 9 to 100, and showed two distinct trends: populations with either decreasing or increasing resistance. Resistance to azamethiphos was found to be widespread and high. Although two strains with high methomyl and propetamphos resistance were observed, methomyl and propetamphos resistance is moderate and appears not to be increasing. © 2001 Society of Chemical Industry     

由腈基到氨基甲酸酯的方法

通过H2O2和NaOH作用,先将腈基转化为相应的酰胺,然后在NBS和DBU的条件下,制备出相应的氨基甲酸酯,结构经1HNMR和元素分析确证。这个新方法对含腈基和酰胺的结构改造,开发新型结构具有潜在的应用价值。     

九种农药制剂和一种叶面肥中有机磷和氨基甲酸酯类隐性成分的快速检测

建立了一种针对9种农药制剂和1种叶面肥中隐性添加23种有机磷或氨基甲酸酯类农药的快速检测方法。将农药制剂和叶面肥用磷酸盐缓冲溶液稀释静置后取上清液,加入乙酰胆碱酯酶溶液和显色剂,摇匀后反应5 min,加入底物后通过农药残留速测仪在波长412 nm处测定0~3 min的吸光度变化值。此外,对氧乐果、甲拌磷和甲基对硫磷在9种农药制剂和1种叶面肥中的检出限进行了验证。结果表明:该方法检出限在0.03~4.4 mg/L之间,当在9种农药制剂和1种叶面肥中的添加水平略低于检出限时,其抑制率均50%(为56%~100%)。本方法可用于定性判断农药制剂中是否添加了上述隐性成分。     

竹纤维研究进展

介绍了竹纤维的天然特性与优点,及其在功能性保健纺织品方面上的应用,简要阐述了竹原纤维、竹浆纤维、竹炭、纤维、竹纤维素氨基甲酸酯和纳米改性竹炭的原理及生产工艺流程,对我国竹纤维的发展现状进行了综述,并对未来发展趋势进行了展望。     

高效液相色谱-质谱联用测定红酒中的氨基甲酸甲酯

[目的]建立一种测定红酒中氨基甲酸甲酯(MC)的高效液相色谱-质谱联用法(HPLC-MS)。[方法]对样品采用0.45μm微孔滤膜过滤后,用氨基固相萃取小柱进行提取、纯化和氮吹浓缩处理,然后用HPLC-MS进行定性定量分析。HPLC条件为:色谱柱,氰基农残色谱柱(250 mm×4.60 mm i.d.,5μm);流动相,乙腈-水(0.1%乙酸)80∶20;流速0.8 ml/min;检测波长195 nm;柱温25℃;进样量20μl。质谱条件:离子源为电喷雾离子源(ESI+源),扫描方式为正离子扫描,干燥气流速为8.0 L/min,干燥气温度为350℃,扫描范围为50～200 m/z,雾化气压力为275.8 kPa。[结果]MC在0.1～20μg/ml范围内线性关系良好,相关系数r为0.996 0。平均回收率为83.40%,RSD为6.8%。[结论]所建立的方法具有较好的精密度和准确度,并具有样品处理简单、检测限低、分析时间短等特点,适于红酒中MC的测定。     

2-硫代-1,3-噻唑烷-3-甲酸酯的合成及生物活性

为了寻找新的含噻唑杂环的先导化合物,利用2-硫代-1,3-噻唑烷与氯甲酸酯在三乙胺存在下进行缩合反应,合成了11个2-硫代-1,3-噻唑烷-3-甲酸酯类化合物,并利用1H NMR、IR、 MS及元素分析对其结构进行了表征;通过X-ray单晶衍射测定了2-硫代-1,3-噻唑烷-3-甲酸苯酯( 3i )的晶体结构,证实反应产物为硫酮式而非硫酯式结构。 初步生物活性试验结果表明,在试验浓度下部分目标化合物具有一定的杀菌和杀虫活性,其中 3c、3f、3h、3k 在500 mg/L下对棉红蜘蛛Tetranychus urticae的致死率均在70%以上。     

高效液相色谱法检测防腐橡胶木中的碘代丙炔基丁基氨基甲酸酯

橡胶木中淀粉含量远高于其他树种,易发霉、蓝变。碘代丙炔基丁基氨基甲酸酯（3-iodo-2-propynyl butyl carbamate,IPBC）绿色环保,对霉菌、蓝变菌有特效,尤其适用于橡胶木保护。目前橡胶木中IPBC分析方法的研究报道较少,其防腐处理材的质量监督尚缺乏有效手段。为了准确分析防腐橡胶木中的IPBC,建立了一种高效液相色谱（high-performance liquid chromatography,HPLC）方法,检验了该方法的检出限、加标回收率等性能,并比较了不同提取方法、提取溶剂、木粉粒径等因素对防腐橡胶木中IPBC提取效果的影响。建立的HPLC方法使用C18反相色谱柱,乙腈-水（55︰45,V/V）为流动相,流速1.0 mL/min,检测波长204 nm,IPBC保留时间约6.45 min。在2~80 mg/L浓度范围内,线性关系良好,相关系数0.9998;检出限0.2 mg/L,平均加标回收率99.61%。超声法提取的效果显著优于索氏抽提器法;以甲醇或甲醇-水（9︰1, V/V）混合液为溶剂超声提取的效果较好,乙酸乙酯和石油醚不适于提取木材中的IPBC。以甲醇-水（9︰1, V/V）混合液为溶剂制备样品可改善色谱峰形,有助于提高分析方法的准确性。木粉粒径差异对IPBC超声提取的影响较小。高温条件会导致IPBC降解,严重影响分析结果准确性,因此在整个分析过程中应避免高温条件。本方法检出限低、重现性好,准确性高,适于分析防腐木材中微量的IPBC。     

碘代丙炔基丁基氨基甲酸酯复配制剂用于橡胶木防霉防蓝变效果检测

将具有较好杀菌效果的碘代丙炔基丁基氨基甲酸酯(IPBC)和二癸基二甲基氯化铵(DDAC),用于橡胶木防霉防蓝变处理。室内试验显示,单方IPBC制剂和IPBC与DDAC复配制剂处理的木材,均具有较优的防霉防蓝变性能,且复配制剂处理效果更优;野外试验显示,采用常压处理和真空加压处理后,复配制剂处理材的防霉防蓝变性能可满足橡胶木加工初期生产周转的要求。     

Filariasis vector in China: insecticide resistance and population structure of mosquito Culex pipiens complex

Seven field populations of mosquito Culex pipiens complex (Diptera: Culicidae) were collected from four provinces of China. The resistance status of larvae to dichlorvos, parathion, chlorpyrifos, fenobucarb (BPMC) and propoxur were determined by bioassays, disclosing that they were more resistant to organophosphate (moderate or low resistance) than to carbamate (low or no significant resistance) insecticides. Starch gel electrophoresis confirmed the presence and distribution of overproduced esterases B1, A2-B2, A8-B8 and A9-B9, the frequencies of which varied according to their regional origins. Electrophoretic polymorphism at four putatively neutral loci (got-1, got-2, pgi and pgm) showed that the overall genetic differentiation found across all populations was significantly large (Fst = 0.28, P < 10(-4)), and genetic exchange was slightly restricted by distance isolation (P = 0.018).