Increased content of phenolic compounds in pear leaves after infection by the pear rust pathogen

European pear rust induced by the fungus Gymnosporangium sabinae (Dicks) G. causes yellow to bright orange leaf spots on leaves of pear trees. The aim of this study is to identify and quantify polyphenolic compounds found in pear leaf extracts. Identified were: ten hydroxycinnamates, eight flavonols, nine flavan-3-ols and three arbutin derivatives. Polymeric procyanidins were additionally determined by UPLC-FL. The total content of phenolics in the control healthy green leaf extract was 11,889.98 mg but in the infected leaves it reached 28,573.89 mg in the samples with yellow spots and 11,480.06 mg/100 g dry matter (dm) in the green part of leaves. The yellow spots in pear rust leaves were characterized by increased content of flavanol (catechins and procyanidins) and arbutin compounds compared with the green part of the infected leaves and control healthy leaves.     

QuEChERs-LC-MS/MS快速分析稻谷中12种农药残留方法初探

采用乙腈作为提取剂,通过QuEChERs方法净化,LC-MS/MS检测稻谷中12种农药残留量。通过对比选择50 mg无水硫酸镁、50 mg PSA、20 mg C18作为QuEChERs净化方法的吸附剂,采用0.1%甲酸和2 mmol/L乙酸铵混合水溶液和乙腈作为流动相,LC-MS/MS检测。结果表明,目标化合物线性范围良好,R0.99,加标回收率为70.3%~118.5%,相对偏差小于20.0%。可见,该方法不仅操作简单,成本低,效率高,还能最大限度减少有机溶剂的使用,环保节能,能满足稻谷中农药残留的检测以及确证工作。     

基于LC-MS技术高通量筛选产Cardiogenol C的芽胞杆菌

Cardiogenol C是目前治疗心脏疾病的一种重要药物,本研究采用LC-MS的技术高通量从51株芽胞杆菌中筛选产Cardiogenol C的菌株。利用MassHunter软件对分子特征进行提取,根据保留时间及精确分子量等信息在Metlin代谢数据库中进行快速的比对,高通量的对代谢产物进行鉴定。筛选鉴定到1株解淀粉芽胞杆菌FJAT-17934 Bacillus amyloliquefaciens产Cardiogenol C,其相对含量为1.02%,匹配度达到了92.08%,保留时间为3.651 7min。这为微生物源的Cardiogenol C的研发奠定理论基础。     

食糜样本中11种生物胺同步检测方法的建立

旨在建立一种利用液质联用（liquid chromatography mass spectrometry,LC-MS）技术实现对猪肠道食糜中多种生物胺进行同步检测的方法。试验首先优化了丹磺酰氯（dansyl chloride,DNS）对生物胺的衍生条件,并进一步确定了肠道食糜样品中生物胺的最佳净化方法。结果显示,衍生条件在衍生剂浓度为8 mg·mL^-1,衍生温度为40℃的条件下,衍生90 min为最佳。生物胺净化方法确定为先用乙酸乙酯进行提取,衍生结束后再用乙酸乙酯进行萃取的组合方式提取生物胺的效果最好;11种生物胺在5～1 000 μg·L^-1的质量浓度范围内定量结果呈良好的线性关系（R²>0.99）,检出限和定量限分别为0.01～0.23 μg·L^-1和0.03～0.76 μg·L^-1;各生物胺的日内相对标准偏差在0.73%～ 7.92%,日间相对标准偏差在0.07%～8.67%。最后采用本方法对仔猪回肠、盲肠、结肠和直肠食糜样品中的生物胺进行检测,初步确定了11种生物胺在不同肠段食糜中的含量分布。通过对仔猪回肠、盲肠、结肠和直肠中的食糜样品进行检测,发现食糜中的生物胺主要为亚精胺、腐胺、尸胺、精胺和组胺,而酪胺、1,7-二氨基庚烷、5-羟色胺和胍基丁胺4种生物胺含量较少,色胺和苯乙胺未检出。综上所述,本试验建立的方法具有结果准确、灵敏度高、重现性好等优点,可用于仔猪不同肠道段食糜中多种生物胺的同步检测。     

豪猪血蜱卵蛋白成分初步鉴定及其功能分类

旨在探明豪猪血蜱卵原生质蛋白成分,为探索干扰蜱类胚胎发育和新型控蜱策略奠定基础。采用FASP法消化豪猪血蜱卵蛋白提取物,LC/MS/MS法对其进行分析、检测,搜索褐黄血蜱卵巢转录组文库、唾液腺转录组文库和中肠转录组文库,分别检出特异性肽段359、312、357条,鉴定多肽108、170、161条,终而鉴定高可信蛋白103种。豪猪血蜱蜱卵原生质中富含酶类、蛋白酶抑制剂、转运蛋白、细胞骨架蛋白、蛋白质合成与修饰、分泌蛋白以及未鉴定的蛋白共8类蛋白。     

Determination of Indoxacarb Residue in Foodstuffs of Plant and Animal Origin by GC-ECD and LC-MS/MS

An effective method for the trace analysis of indoxacarb residue in foodstuffs of plant and animal origin [grapefruit, ginger, fresh soybean, bamboo shoot, qing-gen-cai （cruciferous vegetable）, chicken, fish, and pork] was developed using gas chromatography （GC-ECD） and liquid chromatography tandem mass spectrometry （LC-MS/MS）. Samples were extracted using acetone and n-hexane mixed solvent （1：2, v/v） and then purified using solid-phase extraction （SPE） columns. The extracts were analyzed using GC-ECD and LC-MS/MS. The multiple reaction monitoring （MRM） scheme used involved transitions of the precursor ions to selected two product ions in which one pair for identification was m/z 529 → 293 and another pair for quantification was m/z 529 → 249. The detection limits （LODs） of the method were 0.0015 and 0.0006 mg kg^-1, and the quantification limits （LOQs） were 0.005 and 0.002 mg kg^-1 for GC-ECD and LC-MS/MS, respectively. The relative standard deviations （RSDs） of recovery for indoxacarb were lower than 15% in 10 types of agro-products. Ten repetitive determinations of recovery achieved good reproducibility for indoxacarb and the recovery ranged from 72.08 to 113.74%. The proposed procedure was applied to the analysis of several real samples of different origin from Fujian Province, China, and 299 samples were screened for indoxacarb residue, of which 5 positive samples were found.     

LC-MS/MS测定鱼肉中的孔雀石绿及其代谢物残留及基质效应分析

应用高效液相色谱—串接质谱联用技术测定了鱼肉中的孔雀石绿(MG)及其代谢物隐色孔雀石绿(LMG)的残留,样品经过缓冲溶液提取后,经二氯甲烷反萃取后浓缩,残渣用乙腈+0.1%甲酸水溶液(1+1)溶解,通过Aglientextend C18色谱柱分离后进质谱测定,采用电喷雾离子源。结果表明,对于LMG,MG质量浓度在0.1~200μg/L内均呈线性关系,MG和LMG的检出限分别为0.01μg/mL和0.001μg/mL。以鲤鱼为基质,采用提取后添加方式配制了与纯标准样品浓度相同的标准曲线,研究了基质效应对LMG,MG的影响,样品基质对LMG,MG响应表现为抑制作用,并且抑制作用随浓度的增加而减弱。在基质效应相同的情况下,MG更容易受基质的影响。在质量浓度1.0,50.0μg/mL的标准加入水平下,采用样品基质提取前添加和样品基质提取后添加的方式,计算了样品提取回收率(RE)和方法前处理效率(PE)。     

液质联用法检测土壤中20种常见农药残留

[目的]建立一种高效液相色谱-串联质谱联用法同时检测土壤中多种农药残留的方法.[方法]样品经调节含水量后使用乙腈振荡提取、盐析离心分层并取上清液经吸附剂净化,用高效液相色谱-串联质谱法测定,内标法定量.[结果]方法的线性范围为10～500 μg/L,检出限为0.2～1.7 μg/kg,加标回收率为76.05％～114.87％.[结论]该方法简单、快速,可实现对土壤中多种农药残留的同时测定.     

环境因子对脱氧雪腐镰刀菌烯醇在小麦中残留降解的影响（英文）

利用三重四级杆液质联用仪LCMSMS研究了环境因子对小麦籽粒中DON毒素的降解影响,不同处理得到的DON毒素降解半衰期范围在54.57~71.44 d,150 d后降解率为78.85%~87.00%,对毒素的降解有加快作用的是自然光强光(10 000 lx)黑暗,90%湿度50%湿度,而高温并不能加快毒素的降解。