葛仙米对丁草胺胁迫的响应

研究了丁草胺对可食用蓝藻葛仙米(Nostoc sphaeroides)生理和代谢活性的影响．用不同浓度的丁草胺处理葛仙米,结果显示低浓度(5 mg·L-1)丁草胺使其光合作用、呼吸作用和光合系统Ⅱ活性增强,高浓度丁草胺(>5 mg·L-1)限制其光合作用、呼吸作用和光合系统Ⅱ活性．同时丁草胺对葛仙米膜结构和功能具有破坏作用,随着丁草胺处理浓度增大,质膜透性不断增大,丙二醛和超氧自由基阴离子含量升高；在低浓度丁草胺处理时,类胡萝卜素含量增加,超氧化物歧化酶(SOD)活性增强,高浓度丁草胺处理时,类胡萝卜素含量降低,SOD活性下降；表明葛仙米对低浓度的丁草胺胁迫具有一定的耐受能力,但高浓度的丁草胺对其生理和代谢构成威胁；针对目前葛仙米野生生境中丁草胺的用量,建议限制丁草胺在葛仙米产地的使用,以保护日益稀缺的葛仙米资源．     

加速溶剂萃取-气相色谱质谱法测定太子参中酰胺类除草剂的含量

建立了太子参中乙草胺、丁草胺和S-异丙甲草胺的加速溶剂萃取-气相色谱/质谱测定的分析方法。对提取溶剂、萃取温度、净化材料、不同冲洗体积和静态萃取时间、循环次数等实验条件进行了优化。用HP-5MS弹性石英毛细管柱经柱程序升温技术分离,并用质谱检测器检测,内标法计算含量。本方法测定太子参中乙草胺、丁草胺和S-异丙甲草胺的检出限分别为0.16 ng/g、0.18 ng/g和0.05 ng/g,精密度分别为2.6%、3.9%和3.1%,回收率为80.2%-104.1%。所测样品不含上述3种除草剂残留。本方法简便、干扰小、检测效果好,可用于太子参药材中此类除草剂残留的分析。     

气相色谱法同时测定西草净、丁草胺和噁草灵

采用气相色谱法,以癸二酸二正丁酯为内标物,对新研制的复合型稻田除草剂26％丁··西乳油进行了一次性定量分析。色谱条件为5％SE-302m×3mm的玻璃柱,柱温为210℃,检测温度为230℃。方法的回收率为98．62％～100．77％,线性相关系数大于0．999。方法准确、简便、快速。     

气相色谱法测定土壤中酰胺类除草剂

建立了从土壤中同时提取甲草胺、乙草胺和丁草胺并采用气相色谱法测定的分析方法。采用丙酮-石油醚(2:1,V/V)为提取液,经弗罗里矽硅土固相萃取柱净化,超声30 min、振荡10 min。测定结果显示,甲草胺、乙草胺、丁草胺的保留时间分别为16.333,16.019,20.249 min;线性相关系数>0.9990;6个平行样品在0.10,0.50,0.90 mg/kg的添加水平回收率在84.9%~101.0%之间;对3种酸碱度不同的土壤样品进行了重复测定,得到相对标准偏差(RSD)在0.88%~4.3%之间。方法的检出限分别为甲草胺300 ng/kg,乙草胺400 ng/kg,丁草胺400 ng/kg。定量限分别为甲草胺3.3μg/kg,乙草胺3.9μg/kg,丁草胺3.9μg/kg。方法可同时检测土壤中甲草胺、乙草胺、丁草胺残留量。     

Cellular toxicity and pharmacokinetic study of butachlor by ultra-performance liquid chromatography-tandem mass spectrometry based on tandem mass spectrometry cubed technique

Butachlor is an aromatic amide compound that plays a role as a herbicide, a xenobiotic, and an environmental contaminant. The aim of this work was to develop a highly selective and sensitive ultra-performance liquid chromatography-tandem mass spectrometry method based on the tandem mass spectrometry cubed technique to determine butachlor in a biological matrix. Butachlor and internal standard acetochlor were separated on a Waters Acquity ultra-performance liquid chromatography BEH C₁₈ column (2.1 × 50 mm, 1.7 μm) with gradient elution using 0.1% formic acid aqueous solution (A) and acetonitrile (B) as mobile phases. The transitions selected for tandem mass spectrometry cubed quantitative analysis in positive ion mode were: for butachlor, mass-to-charge ratio 312.2→238.1→162.1; for acetochlor, mass-to-charge ratio 270.1→224.0→148.1. The total running time for each sample was 5.5 min. The ultra-performance liquid chromatography-tandem mass spectrometry cubed method showed a linear relationship (R² ≥ 0.995) in the concentration range of 0.5–100 ng/ml. The intra and interday accuracies are within the range of -10.6%–4.3% and precisions are between 4.48% and 13.14%. The novelty of the method is the use of tandem mass spectrometry cubed scanning mode, which improves selectivity and sensitivity. The results indicated that butachlor was cellular toxic. The safety of butachlor should be considered when it is used as a herbicide.