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安捷伦推出针对GC/MS/MS农药分析的综合参考指南涵盖最新食品检测方法和技术本刊讯(记者逯文娟)安捷伦科技公司于6月20日推出了《GC/MS/MS农药残留分析指南》。该综合参考指南是Excellcon International,LLC.公司总裁Katerina Mastovska博士与加州食品与农业部、佛罗里达州农业与消费者服务部,以及安捷伦科学家的合力之作。     

固相萃取(SPE)和衍生化条件的对GC/MS及LC/MS/MS法检测莱克多巴胺灵敏度的影响(英文)

本实验探讨影响GC/MS以及LC/MS/MS检测灵敏度的影响因素。对GC/MS法的固相萃取(SPE)和衍生化条件进行优化,测试了SPE、加热时间、温度、溶液及碱基化等因素。同时测试这些条件对LC/MC/MC法的灵敏度。结果表明,碱基化为影响GC/MS法灵敏度的主要因素,能提高灵敏度,对衍生化条件也有影响。通过对样本进行固相萃取,碱基化处理,GC/MS法的灵敏度为0.5ng/mL,LC/MC/MC法的为0.25ng/mL。采用这种更灵敏的方法,尿液中莱克多巴胺的测试窗口期可由2d提高到6d。经过优化的GC/MS法及LC/MS/MS方法灵敏度更高,适合猪尿中莱克多巴胺的检测。     

GC-MS测定白酒中氨基甲酸乙酯的不同预处理方法的比较

比较了固相萃取(SPE)、固相微萃取(SPME)、双水相萃取(LLE)作为预处理方法萃取白酒中氨基甲酸乙酯的效率,并联合气相色谱-质谱(GC-MS)对白酒中氨基甲酸乙酯进行测定,通过方法学验证评价各方法的准确度和精密性。结果显示:对于三种香型的白酒来说,SPE-GC/MS法检测精密性最好(1.77%~2.96%)、准确度最高(回收率89.73%~103.51%),检测限最低(1.12μg/L);SPME-GC/MS方法检测清香型白酒的效果优于LLE-GC/MS;LLE-GC/MS方法检测浓香型、酱香型白酒效果优于SPME-GC/MS方法。综合考虑各因素,LLE-GC/MS因其准确度较高、精密度较好、简便快速、成本低经济、有机溶剂用量少环保、易于掌握,满足一般性定量检测要求,适合用于我国白酒中氨基甲酸乙酯含量的常规分析检测。SPE-GC/MS准确度高、精密度良好,但由于操作过程繁琐、成本高、有机溶剂用量多不环保,适用于精密分析。     

食用油脂中3-MCPD脂肪酸酯和缩水甘油脂肪酸酯分析方法研究进展

随着对油脂中3–MCPD脂肪酸酯(ME)和缩水甘油脂肪酸酯(GE)研究和检测技术的不断更新,在精炼棕榈油中发现了ME存在,且在大多数食用油脂中发现了GE存在。ME和GE作为两类食用油脂加工过程中产生的污染物,对人体可能存在致癌性。目前对ME和GE的检测有直接方法和间接方法 2种,直接方法主要是对油样处理或不处理后直接用LC–MS、LC–MS/MS、LC–TOF–MS、GC–MS等进行检测;间接方法是将ME和GE醇解为3–MCPD和缩水甘油酯,苯硼酸或七氟丁酰咪唑衍生化后用GC–MS或GC–MS/MS检测。该文对现有的ME和GE检测方法的样品处理过程、仪器条件、结果等加以比较和分析探讨。     

安捷伦发布最新三重四极杆气质联用系统

2013年9月5日，北京安捷伦科技公司发布7000C三重四极杆气质联用系统（GC/MS/MS）。该系统新增多项功能，可大幅改进系统性能、简化方法优化并显著降低运行成本，成为继业内最畅销的安捷伦7000B之后又一款GC/MS/MS新品。     

甘蔗新品种桂糖48号的组织培养技术研究

甘蔗组织培养技术是加速繁殖新品种和加快新品种大面积推广的主要手段,不同品种的离体培养中其培养基中激素配比存在差异,因此筛选合适培养基是提高品种快繁效率的关键。本文以桂糖48号为材料,以MS基本培养基加外源激素浓度梯度进行试验处理设计,对品种的愈伤组织诱导、愈伤分化、试管苗增殖和生根阶段进行培养基筛选试验,以其筛选出最合适桂糖48号的培养基配方。试验结果表明:诱导愈伤组织培养基为MS+2,4-D 3.0 mg/L;愈伤组织分化培养基为MS+BA 1.0 mg/L;初代增殖培养基为MS+BA 2.0 mg/L+NAA 0.1 mg/L+GA 0.5 g/L;继代培养基为MS+BA 2.0 mg/L+NAA 0.1mg/L;生根培养基为1/2 MS+NAA 12 mg/L。在该培养基下,生根最好,苗绿,比较高,长势好,对加快甘蔗新品种桂糖48号在广西大面积推广起到积极的作用。     

研究人员采用新方法分析干果中多种霉菌毒素

<正>据施普林格全文数据库信息,2014年1月,研究人员采用LC/MS/MS法以及改进的QuEChERS程序分析干果中多种霉菌毒素。近日,研究学者开发出可同时检测干果中16种霉菌毒素的方法,且灵敏度、准确性均很高。此法采用LC/MS/MS以及改进的QuEChERS程序。改进的QuEChERS程序使提取样本中的真菌毒素更快     

塑料包装材料中邻苯二甲酸酯的LC/MS/MS测定方法研究

建立了LC/MS/MS测定塑料包装材料中邻苯二甲酸酯含量的分析方法.将塑料包装材料粉碎后索氏提取,经LC/MS/MS分析在50μg/L～400μg/L范围内呈现良好的线性关系(R2＞0.9985),方法检测限小于35μg,/kg;在50μg/kg、200μ g/kg、400μg/kg三个样品加标水平,PAEs的回收率在91.42％～99.90％之间;方法精密度实验的相对准偏差在5％之内.结果表明该方法准确可靠,精密度较高.     

红宝石无核和SO4单芽茎段的增殖与成苗培养

以葡萄栽培品种红宝石无核和砧木SO4的单芽茎段为材料,研究葡萄的初代培养与增殖培养.结果表明,升汞的最佳消毒时间为12min、13min;红宝石无核最适初代培养基为1/2MS+6-BA1.0mg/L+NAA0.1mg/L,砧木SO4的最适培养基为1/2MS+6-BA1.5mg/L+NAA0.1mg/L;红宝石无核继代增殖的最适培养基为MS+6-BA0.8mg/L+IBA0.2mg/L,砧木SO4为MS+6-BA1.0mg/L+IBA0.2mg/L.两品种最佳生根培养基为1/2MS+IBA0.4mg/L,红宝石无核生根率达98%,而SO4则达100%.     

GC与GC/MS定量分析香料的比较

分别采用气相色谱法(GC)、气相色谱/质谱总离子流法[GC/MS(TIC)]、气相色谱/质谱选择离子法[GC/MS(SIM)]3种仪器测定方式和2种定量方法———峰面积归一化法和内标标准曲线法对13种香料标样进行了定量分析比较。比较的内容包括:测试方法的重复性、内标标准曲线以及应用内标标准曲线的定量结果。结果表明:①对于内标标准曲线法,GC和GC/MS(SIM)分析的13种香料的CV均不大于1%,多数香料的内标法标准曲线的r>0.999,显示出很好的线性关系和重复性,适宜进行准确的定量分析;②GC/MS(TIC)分析的重复性以及所得内标法标准曲线的线性关系一般;③3种仪器测试方式的峰面积归一化法定量结果与实际情况偏差较大,尤其是2种GC/MS方式。     

三聚氰胺检测五LC/MS/MS法分析食品中的三聚氰胺

奶粉类食品前处理 1.所需试剂及耗材 1%三氯乙酸溶液,0.1mol/L盐酸溶液,5%氨水-甲醇溶液,以及Oasis MCX固相萃取柱(60mg/3mL,或相当者),使用前分别用3mL甲醇、3mL0.1mol/L盐酸溶液对固相萃取柱进行预处理,并保持柱体的湿润.     

Determination of aflatoxins in food using LC/MS/MS

 A liquid chromatography/atmospheric pressure chemical ionization tandem mass spectrometric method is described for the determination of aflatoxins B₁, B₂, G₁ and G₂ in food with the use of aflatoxin M₁ as an internal standard. The method works well with matrices such as those of figs and peanuts, but there are problems with spices, due to limitations of the clean-up method used. Received: 15 October 1997     

液相色谱-串联质谱术在生态纺织品检测中的应用

伴随人们环保和安全意识的提高,生态纺织品的安全检测越来越受到人们的关注.本文介绍液相色谱-串联质谱技术在生态纺织品有害物质,如禁用偶氮、致癌致敏染料、烷基酚聚氧乙烯醚、杀虫剂残留测定中的应用.     

Multiresidue method for pesticides and veterinary drugs in bovine milk using GC/MS and LC/MS/MS

A simple, sensitive and selective method with gas chromatography/mass spectrometry (GC/MS) and liquid chromatography/tandem mass spectrometry (LC/MS/MS) has been developed to detect 342 pesticides and veterinary drugs contaminating bovine milk at the maximum residue limits (MRLs) defined in the "positive list system". Sample preparation was performed by extracting the analytes with acetonitrile, followed by salting-out with sodium chloride. For some pesticides, the extract was further cleaned up by n-hexane partitioning and PSA cartridge column chromatography. GC/MS-EI or -NCI was used to determine pesticide residues, while LC/MS/MS-ESI was applicable to the determination of pesticide and veterinary drug residues. The variation of the recoveries of these drugs at MRL was relatively wide; however the relative standard deviations of the recovery of each drug were within 28%, suggesting that the present method is good enough for use as a screening test for contaminants at the MRLs. These results show that this method is useful for multiresidue analysis of numerous pesticides and veterinary drugs in bovine milk.     

Simultaneous determination of quinolones in foods by LC/MS/MS

A simple method was developed for the simultaneous determination of seven quinolones (enoxacin, ofloxacin, ciprofloxacin, danofloxacin, lomefloxacin, enrofloxacin and sarafloxacin) in foods using liquid chromatography coupled with electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS). The seven quinolones were extracted with acetonitrile containing 0.2% formic acid, and the extracted solution was cleaned up on a C18 cartridge. The extract was diluted with 5 mmol/L IPCC-MS3 for injection into the LC-ESI-MS/MS. The LC separation was carried out on an ODS column with gradient elution of 5 mmol/L IPCC-MS3-acetonitrile as the mobile phase. Mass spectral acquisition was done in the positive ion mode by applying selected reaction monitoring (SRM). The recoveries of the seven quinolones were mostly greater than 60% from foods fortified at 10 ng/g. The detection limits in foods were 2 ng/g for enoxacin and ciprofloxacin, and 1 ng/g for the other drugs. Twenty cattle muscle, 7 swine muscle, 9 chicken muscle, 16 milk, 19 prawn and 20 broiled eel samples from retail markets were analyzed by this method. Enrofloxacin and its metabolite ciprofloxacin were detected in 9 broiled eel at the level of trace (tr)-34 ng/g and tr-10 ng/g, respectively.     

Direct nanoHPLC-ESI-QTOF MS/MS analysis of tryptic caseinophosphopeptides

Caseinophosphopeptides (CPPs) were generated following tryptic hydrolysis of sodium caseinate. Hydrolysate peptides were separated and identified using nano-HPLC ESI-QTOF MS/MS. Sequence coverage in the 3 h hydrolysate was 79.4%, 55.6%, 80.9% and 68.1% for α_s1-, α_s2-, β- and κ-casein (CN), respectively. Variable levels of serine phosphorylation in β-CN f1–25 were observed in the 3 h hydrolysate. Analysis of β-CN f1–25 4P demonstrated that this peptide was stable during the course of hydrolysis. The effect of heat treatment (75 °C, 45 min) at pH 6.0, 7.0 and 8.0 on the peptide profile of the 3 h hydrolysate was studied. Compared to pH 6.0 and 8.0, least modification in phosphopeptide profiles was observed for the hydrolysate sample heated at pH 7.0. Different dephosphorylation and oxidation patterns were also observed following heat treatment at the three pH values. These results demonstrate that heat treatment, in addition to pH, has a major effect on both the phosphorylated and non-phosphorylated peptide profiles of CN hydrolysates.     

液相色谱-电喷雾串联质谱法测定豇豆中的水胺硫磷

建立了豇豆中水胺硫磷的液相色谱-电喷雾串联质谱分析方法。样品经乙腈超声提取后进行液相色-电喷雾串联质谱分析。方法检出限为0.1μg/kg(S/N=3)。空白样本添加水平在0.1、1.0、5.0μg/kg时,平均回收率为80.1~87.9%,相对偏差(n=6)为6.7~8.1%。使用MRM-IDA-EPI的模式,一次进样可得到MRM色谱图及MS2质谱图。该方法具有前处理简单、回收率高、精密度好,选择性强,灵敏度高的优点,符合农药残留的分析要求。     

基于UPLC/Q-TOF MS/MS的花生油成分分析

采用超高效液相色谱-串联四级杆飞行时间质谱(UPLC/Q-TOF MS/MS)联用仪对花生油甲醇提取液分离检测,分析花生油成分,并通过二级质谱图和标准品确定物质。结果表明:正离子模式下检出86种化合物,鉴定30种物质,其中芥酸、棕榈酰胺、硬酯酰胺、油酸酰胺、11Z-二十二碳二烯酸为已知的花生油成分,亚油酰乙醇胺、亚油酰胺、鞘氨醇、N-油酰乙醇胺、十八碳四烯酸、顺-4-癸二酸等26种物质均为首次被检出;在负离子模式下,共检出27种化合物,鉴定15种物质,其中包括花生油中常见的7种脂肪酸,首次检出(Z)-13-氧-9-十八烯酸、蓖麻油酸、烯油酸、13-羟基十八酸和2(R)-羟基海藻酸5种脂肪酸和其他3种物质。     

基于UPLC/Q-TOF MS/MS的芝麻油成分分析

为发现芝麻油中新成分,通过UPLC/Q-TOF MS/MS对4种芝麻油甲醇提取液进行检测分析。结果表明：4种芝麻油中共发现143种共同物质,其中正离子模式71种,负离子模式72种。共同物质中鉴定出77种物质,其余66种为未鉴定成分;77种鉴定成分中包括脂肪酸及衍生物(8种)、芝麻素、芝麻林素、硬脂酰胺等12种已知成分,其余65种为新发现成分;新发现成分包括油酸酰胺、棕榈酰胺、亚油酰胺、芥酸酰胺、8-甲基-N-香草基壬酰胺、辣椒酰胺、N-硬脂酰丙氨酸等17种脂肪酸酰胺,十六碳烯酸、十八碳烯酸等22种脂肪酸及衍生物,5-脱氧基维醇、天孢菌素等5种类黄酮,马泰树脂醇、银杏酸等21种其他成分。芝麻油中含有大量新成分和未知成分,富含的脂肪酸、脂肪酸酰胺、类黄酮、木脂素等物质可解释其独特生理功能。