超高效液相色谱–电喷雾串联质谱测定蔬菜水果中27种常见农药残留

建立了蔬菜水果中27种常见农药残留超高效液相色谱–电喷雾串联质谱(UPLC–ESI–MS/MS)测定方法。样品用乙腈均质提取,加入无水硫酸镁和氯化钠盐析分层,经CARBON/NH2固相萃取柱净化,乙腈–甲苯(3∶1,v/v)洗脱,旋转蒸发浓缩,用乙腈–0.1%甲酸(1∶1,v/v)溶解,以电喷雾串联质谱在多反应监测模式(MRM)下进行测定。分析方法结果表明,多数组分在5～100μg/L范围内线性良好(r2=0.991～0.999),在10～50μg/kg范围内,27种农药的回收率为65.81%～124.7%,相对标准偏差为3.6%～19.2%。方法的检出限和定量限范围分别为0.05～5μg/L和0.2～18μg/L。该方法操作简便、快捷、灵敏,灵敏度、准确度和精密度均能满足农药多残留检测的技术要求,适用于蔬菜水果中常见农药残留的检测。     

30%稻瘟灵展膜油剂在水稻、田水及土壤中的残留与消解动态分析

[方法]稻瘟灵是我国水稻生产上防治稻瘟病的主要杀菌剂之一。为明确30%稻瘟灵展膜油剂在水稻植株、田水及土壤中的残留与消解动态,分别于2011、2012年在水稻田进行稻瘟病防治试验,并在施药后不同时期采集水稻、田水及土壤样本,通过气谱(配ECD检测器)进行相关样本的药剂残留检测。[结果]2011年,稻瘟灵在水稻植株、田水和土壤中的原始沉积量分别为37.549 0 mg/kg、1.334 6 mg/L和0.130 1 mg/kg,半衰期(t1/2)分别为4.2、5.2、15.6 d;2012年,稻瘟灵在水稻植株、田水和土壤中的原始沉积量分别为26.867 6 mg/kg、0.927 7 mg/L和0.325 4 mg/kg,t1/2分别为4.9、5.0、13.6 d。最终残留试验表明稻瘟灵在糙米、稻壳、稻株和土壤中的最终残留量分别为0.113 0～1.947 4、2.835 6～10.123 6、0.321 7～2.583 7、0.002～0.124 7 mg/kg。[结论]30%稻瘟灵展膜油剂可以在水稻上使用,但施药剂量最高为540 g/hm2,施药1次,采收间隔期为28 d。     

戊唑醇对花生叶斑病菌和豇豆锈病菌的毒力及田间药效评价

测定了戊唑醇对花生叶斑病菌和豇豆锈病菌的室内毒力,并进行了田间药效试验。毒力测定结果表明,戊唑醇对花生叶斑病菌和豇豆锈病菌的EC50分别为1.85mg/L和8.84mg/L,明显高于对照药剂三唑酮和多菌灵。田间药效试验结果表明,25%戊唑醇乳油用量为8.3～16.7g/667m2时,对花生叶斑病和豇豆锈病的防治效果分别为63.09%～77.33%和61.42%～76.40%,且该使用剂量对上述2种作物均安全。     

贵州铜仁植烟土壤高效氯氰菊酯和甲氨基阿维菌素苯甲酸盐残留状况研究

本研究分别建立了气相色谱-质谱法和液相色谱-质谱法测定植烟土壤中高效氯氰菊酯和甲维盐残留的方法,评估了铜仁市植烟土壤中高效氯氰菊酯和甲维盐的残留状况。试验结果表明,高效氯氰菊酯和甲维盐的质量浓度分别为50～1 000μg/L和0.5～20μg/L时,其对应的分析方法具有良好的线性关系,检出限分别为5μg/kg和0.125μg/kg;分别在0.02～0.15μg/g和0.5～80μg/g范围内,平均回收率为83.9%～100.5%和96.4%～102.5%,相对标准偏差为3.96%～6.43%和1.96%～8.79%。55个植烟土壤中未检测到甲维盐,有1个土壤样品中检出了高效氯氰菊酯,残留量为0.44 mg/kg。铜仁烟区土壤中高效氯氰菊酯和甲维盐残留量较低,具有发展低残留优质烟叶的优越条件。     

碘化钾-Cd(Ⅱ)-罗丹明B离子缔合分光光度法测定土壤中微量镉

将0. 5 g土壤进行消解,采用碘化钾-Cd(Ⅱ)-罗丹明B离子缔合分光光度法测定土壤中微量镉,最佳反应条件:加入2 m L浓度1 mol/L H2SO4,20%碘化钾-抗坏血酸溶液3 m L,显色40 min,在波长588 nm处测定离子缔合物吸光度。结果表明,Cd(Ⅱ)浓度在0. 25～2. 0μg/m L范围内符合郎伯-比尔定律。本方法测定结果相对标准偏差小于2%,方法检出限2. 1μg/kg,加标回收率98. 90%～100. 60%。实验表明,校园内土壤镉含量0. 035～0. 050 mg/kg范围内,几乎无金属镉污染。     

野核桃青皮中胡桃醌含量测定及抗菌活性研究

采用高效液相色谱法测定野核桃青皮中的胡桃醌含量,检测条件为:紫外检测器(HPLC-VWD),反相色谱柱Geminu 5U C18110A (250 mm×4. 6 mm,5μm),色谱柱温度30℃,流动相为甲醇(A)∶1%醋酸水溶液(B)=55∶45,流速0. 8 m L/min,总进样时间20 min,进样量10μL。结果显示,野核桃青皮中胡桃醌含量为0. 84 mg/g,高于本地泡核桃和云南泡核桃的胡桃醌含量;胡桃醌进样量在3～50μg/m L的范围内线性良好(R2=0. 996 4),胡桃醌3个水平(5,10,15μg/m L)的回收率在80. 66%～109. 21%范围内,RSD <10%,方法便捷、稳定,适用于野核桃青皮中胡桃醌含量测定。抗菌活性研究表明,胡桃醌对马尾松溃疡病菌的EC50为102. 751 mg/L,对核桃枝枯病的EC50为112. 808 mg/L。     

高效液相色谱法同时测定苦楝子中的三种有效成分

建立了高效液相色谱同时测定苦楝子中的三种有效成分(香草酸、香兰素、阿魏酸)的方法。苦楝子样品用甲醇超声提取,提取液过滤并用甲醇稀释后分析。采用C18反相色谱柱(250×4.6nm,3.5μm),流动相为乙腈和0.1%醋酸水溶液,梯度洗脱。结果显示:三种有效成分的检出限(LOD)分别为2.5μg/m L、0.82μg/m L和1.3μg/m L,定量限(LOQ)分别为8.4μg/m L、2.7μg/m L和3.4μg/m L,加标回收率为94.9%~104.5%,相对标准偏差小于3.4%,苦楝子样品中的香草酸、香兰素、阿魏酸的平均含量分别是67.98 mg/kg、96.14 mg/kg、36.61 mg/kg(n=6),相对标准偏差分别为1.8%、1.1%和0.7%。该方法重复性好、简单、准确,可用于同时测定苦楝子中的香草酸、香兰素、阿魏酸的含量。     

微量QuEChERS/气相色谱质谱法快速测定土壤中15种农药残留

为实现瓜菜种植土壤中常见农药的快速、灵敏测定,以改进的微量QuEChERS(μ-QuEChERS)辅助超声提取法,结合气相色谱质谱(GC-MS)分析,建立了土壤中15种农药残留的同时快速检测方法。土壤中15种农药残留采用含有V(1%乙酸的乙腈)∶V(二氯甲烷)=2∶1的混合溶液提取,上清液经过w(N-丙基乙二胺(PSA))∶w(C_(18))=3∶1混合吸附剂与无水Na_2SO_4净化。目标物在TG-5MS弱极性石英毛细管柱进行GC分离,以电子轰击电离源(EI)、选择离子监测(SIM)模式的外标法定量。结果表明,超过13种有机污染物在1.0～1 000μg/L范围内呈良好线性关系,且相关系数(r)均超过0.990。所建方法的检出限(LOD,S/N=3)为0.1～1.2μg/kg,定量限(LOQ,S/N=10)为0.5～4.3μg/kg。3个不同添加浓度(5.0、50、200μg/kg)的回收率在73.2%～114.5%范围内,相对标准偏差(RSD,n=3)在1.1%～11.4%范围内。将所建方法应用到海南南渡江流域瓜菜产区土壤中农药残留检测中,观察到土壤中均含有滴滴涕(DDT)、六六六(BHC),且均存在农药多残留情况(≥7种),其中联苯菊酯检测浓度最高。方法简单、快速且灵敏,有机试剂种类和用量少,适合土壤中15种常见农药多残留的同时、快速、批量检测。     

高效液相色谱法测定口腔护理产品中卡松含量及质谱确证

建立了口腔护理产品中卡松含量的高效液相色谱分析方法。以水和甲醇溶解,超声提取过滤后,选用C18?(250?mm×4.6?mm,5?μm)色谱柱,流动相为甲醇和水(45∶55,V/V),以275?nm波长在15?min内进行定量分析。甲基异噻唑啉酮(MIT)和甲基氯异噻唑啉酮(CMIT)分离效果良好,其中甲基异噻唑啉酮的线性范围为0.07～10?mg/L(R20.999?0),检出限和定量限分别为0.2和0.7?mg/kg,实际样品中加标回收率和相对标准偏差范围分别为96.1%～101.4%和1.1%～5.6%;甲基氯异噻唑啉酮的线性范围为0.2～30?mg/L(R20.999?0),检出限和定量限分别为0.6和2?mg/kg,实际样品中加标回收率和相对标准偏差范围分别为96.0%～101.8%和1.0%～2.9%。阳性样品可用液相色谱-串联四级杆质谱(HPLC-MS/MS)进行确证。该分析方法简便、准确、快速,适用于口腔护理产品中卡松含量的测定。     

电感耦合等离子体质谱法(ICP-MS)测定阿奇霉素中金属铂的研究

借助ICP-MS,建立了一种简单、快速的阿奇霉素铂含量的分析方法。在0.1~20μg/L浓度范围内,铂含量的响应值与其对应浓度呈线性关系,其相关系数为0.9999;方法检测限和定量限分别为0.0048 mg/kg和0.016 mg/kg;加标回收实验显示,在(0.1μg/L、6μg/L、20μg/L)3种浓度水平下,各回收率均大于70%,符合分析测试要求。     

Sapindaceae,cyanolipids, and bugs

Scentless plant bugs (Heteroptera: Rhopalidae) are so named because adults of the Serinethinae have vestigial metathoracic scent glands. Serinethines are seed predators of Sapindales, especially Sapindaceae that produce toxic cyanolipids. In two serinethine species whose ranges extend into the southern United States,Jadera haematoloma andJ. sanguinolenta, sequestration of host cyanolipids as glucosides renders these gregarious, aposematic insects unpalatable to a variety of predators. The blood glucoside profile and cyanogenesis ofJadera varies depending on the cyanolipid chemistry of hosts, and adults and larvae fed golden rain tree seeds (Koelreuteria paniculata) excrete the volatile lactone, 4-methyl-2(5H)-furanone, to which they are attracted.Jadera fed balloon vine seeds (Cardiospermum spp.) do not excrete the attractive lactone. Loss of the usual heteropteran defensive glands in serinethines may have coevolved with host specificity on toxic plants, and the orientation ofJadera to a volatile excretory product could be an adaptive response to save time.Mention of a commercial product does not consititute an endorsement by the USDA.     

Insect antifeedant properties of anthranoids from the genusVismia

Vismiones and ferruginins, representatives of a new class of lypophilic anthranoids from the genusVismia were found to inhibit feeding in larvae of species ofSpodoptera, Heliothis, and inLocusta migratoria.     

2008～2009年世界塑料工业进展

收集了2008年7月～2009年6月世界塑料工业的相关资料,介绍了2008～2009年国外塑料工业的发展情况,提供了世界塑料产量、消费量及全球各类树脂的需求量及产能情况。按通用热塑性树脂(聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂)、工程塑料(尼龙、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚)、特种工程塑料(聚苯硫醚、液晶聚合物、聚醚醚酮)、通用热固性树脂(酚醛、聚氨酯、环氧树脂、不饱和聚酯树脂)不同品种的顺序,对树脂的产量、消费量、供需状况及合成工艺、产品应用开发、树脂品种的延伸及应用的进一步扩展等技术作了详细介绍。     

Many Drugs of Abuse May Be Acutely Transformed to Dopamine,Norepinephrine and Epinephrine In Vivo

It is well established that a wide range of drugs of abuse acutely boost the signaling of the sympathetic nervous system and the hypothalamic–pituitary–adrenal (HPA) axis, where norepinephrine and epinephrine are major output molecules. This stimulatory effect is accompanied by such symptoms as elevated heart rate and blood pressure, more rapid breathing, increased body temperature and sweating, and pupillary dilation, as well as the intoxicating or euphoric subjective properties of the drug. While many drugs of abuse are thought to achieve their intoxicating effects by modulating the monoaminergic neurotransmitter systems (i.e., serotonin, norepinephrine, dopamine) by binding to these receptors or otherwise affecting their synaptic signaling, this paper puts forth the hypothesis that many of these drugs are actually acutely converted to catecholamines (dopamine, norepinephrine, epinephrine) in vivo, in addition to transformation to their known metabolites. In this manner, a range of stimulants, opioids, and psychedelics (as well as alcohol) may partially achieve their intoxicating properties, as well as side effects, due to this putative transformation to catecholamines. If this hypothesis is correct, it would alter our understanding of the basic biosynthetic pathways for generating these important signaling molecules, while also modifying our view of the neural substrates underlying substance abuse and dependence, including psychological stress-induced relapse. Importantly, there is a direct way to test the overarching hypothesis: administer (either centrally or peripherally) stable isotope versions of these drugs to model organisms such as rodents (or even to humans) and then use liquid chromatography-mass spectrometry to determine if the labeled drug is converted to labeled catecholamines in brain, blood plasma, or urine samples.     

Methyl 2,4,6-decatrienoates Attract Stink Bugs and Tachinid Parasitoids

Halyomorpha halys (Stål) (Pentatomidae), called the brown marmorated stink bug (BMSB), is a newly invasive species in the eastern USA that is rapidly spreading from the original point of establishment in Allentown, PA. In its native range, the BMSB is reportedly attracted to methyl (E,E,Z)-2,4,6-decatrienoate, the male-produced pheromone of another pentatomid common in eastern Asia, Plautia stali Scott. In North America, Thyanta spp. are the only pentatomids known to produce methyl 2,4,6-decatrienoate [the (E,Z,Z)-isomer] as part of their pheromones. Methyl 2,4,6-decatrienoates were field-tested in Maryland to monitor the spread of the BMSB and to explore the possibility that Thyanta spp. are an alternate host for parasitic tachinid flies that use stink bug pheromones as host-finding kairomones. Here we report the first captures of adult and nymph BMSBs in traps baited with methyl (E,E,Z)-2,4,6-decatrienoate in central Maryland and present data verifying that the tachinid, Euclytia flava (Townsend), exploits methyl (E,Z,Z)-2,4,6-decatrienoate as a kairomone. We also report the unexpected finding that various isomers of methyl 2,4,6-decatrienoate attract Acrosternum hilare (Say), although this bug apparently does not produce methyl decatrienoates. Other stink bugs and tachinids native to North America were also attracted to methyl 2,4,6-decatrienoates. These data indicate there are Heteroptera in North America in addition to Thyanta spp. that probably use methyl 2,4,6-decatrienoates as pheromones. The evidence that some pentatomids exploit the pheromones of other true bugs as kairomones to find food or to congregate as a passive defense against tachinid parasitism is discussed.