色谱-质谱联用技术在食品分析中的应用

综述了近年来色谱-质谱联用技术在食品分析中的应用。这些应用包括气相色谱-质谱联用分析食品中农药残留、兽药残留,以及液相色谱-质谱联用法用于食品中兽药残留,违规食品添加剂、霉菌毒素等的测定。     

全二维色谱飞行时间质谱分析法如何应用于石油地质样品分析

随着我国经济的快速发展,对于石油的需求量也越来越多,在石油的勘测过程中使用全二维气相色谱—飞行时间质谱技术来对开采出来的石油地质样品进行了分析研究,通过使用此项技术来对原油进行分析能够直接显示原油中的组分,各种烃类物质的组成分布在特征区域,此项技术在石油勘探研究中有着非常广泛的的应用。     

气相色谱-质谱联用测定饮用水源中半挥发性有机物

以美国USEPA8270分析方法为基础,参照国内外有关SVOCs分析方法,建立二氯甲烷液液萃取、GC-MS同时定性定量饮用水源中21个组分SVOCs的方法;21种SVOCs的RSD为2.01~8.13%;回收率为40.2~91.5%;方法检出限为0.06~1.00μg/L,均满足地表水环境质量标准(GB3838-2002)中各化合物的标准限值要求;应用于中山市3个饮用水源地样品SVOCs测定,结果满意。     

高纯惰性气体的气相色谱—质谱联用分析

介绍了高纯稀有气体氮、氖、氩、氪、氙的气相色谱－质谱取用分析技术及实验方法。     

清溪乌鳖油脂肪酸的气相色谱-质谱联用分析

采用气相色谱-质谱法对清溪乌鳖油脂中脂肪酸组成进行分析。共检测到22种脂肪酸,其中单不饱和脂肪酸6种,多不饱和脂肪酸9种,饱和脂肪酸7种。清溪乌鳖富含ω-3脂肪酸,含量达16.69%。此外清溪乌鳖油中9-十八碳烯酸（油酸）和9-十六碳烯酸（棕榈油酸）的含量也较高。本研究为清溪乌鳖油在生物制药和营养保健品领域的开发应用提...     

电子轰击离子源脉冲离化电子流的测量

本文讨论了脉冲测量技术在飞行时间质谱计电子轰击离子源中测量脉冲离化电子流的应用 ,分析了平均电流测量方法测量脉冲离化电子流的局限性 ,给出了实际的脉冲测量电路     

气相色谱-质谱联用仪的日常维护

本文作者以型号Agilent 6890 597x四极杆气相色谱-质谱联用仪为例,从载气系统、质谱真空系统、进样系统、色谱柱使用、质谱系统的日常维护等方面进行了较为详尽的阐述与故障分析,以求本文对大家在仪器实际操作过程中能有所帮助.其它型号的气相色谱-质谱联用仪亦可以作参考。     

气相色谱-质谱联用仪信噪比的不确定度评定

信噪比是气相色谱-质谱联用仪的一个重要参数,本文依据JJF1164-2006《台式气相色谱—质谱联用仪校准规范》,介绍台式气相色谱—质谱联用仪信噪比的不确定度评定方法。     

气相色谱-质谱联用内标法测定干性食品包装纸中的N-甲基吡咯烷酮

建立了气相色谱-质谱联用内标法测定干性食品包装纸中N-甲基吡咯烷酮的分析方法。采用超声提取为前处理方式,使用乙醇为溶剂,目标物用GC-MS 进行了测定,内标法定量。探讨了不同萃取溶剂对目标物的提取效率,优选了合适的提取溶剂用量,比较了不同样品的提取方式及条件;甄选出合适的内标物,确定了较佳的特征离子及其丰度比,分析了色谱柱流量、进样量及分流比对目标物分离的影响,得到了合适的色谱分析条件。在优化的实验条件下,目标物N-甲基吡咯烷酮在0. 02745 ~2. 196 mg/ L 范围内具有良好的线性关系,相关系数(R2 )为0. 9999,平均回收率为98. 36 % ~ 108. 29 %,相对标准偏差为3. 71% ~ 6. 05 %,检出限为0. 058mg/ kg,定量下限为0. 194 mg/ kg。该方法简便、快速、灵敏、准确,适合于干性食品包装纸中N-甲基吡咯烷酮的测定。     

Design and Optimization of a Corona Discharge Ion Source for Supercritical Fluid Chromatography Time-of-Flight Mass Spectrometry

The interfacing of capillary column supercritical fluid chromatography (SFC) to time-of-flight mass spectrometry (TOFMS) through atmospheric pressure chemical ionization (APCI) was investigated. An ion source chamber and a new, flexible, and efficient transfer line from the SFC to the TOFMS system were designed to accommodate the requirements of this study. Ionization of analytes was performed using a corona discharge needle. The interface was equipped with two multiple-axis translation stages for positioning of the transfer line tip and the discharge needle inside the ion chamber. The investigations were oriented toward the optimization of parameters which have a strong effect on the intensity and stability of the analyte signal, including background stability, corona discharge needle positioning in the ion source, transfer line tip and discharge needle relative positioning, curtain gas and makeup gas flow interactions, ion chamber temperature, and elution pressure of analytes from the SFC system.     

Polymer Analysis by Liquid Chromatography/Electrospray Ionization Time-of-Flight Mass Spectrometry

Hyphenation of liquid chromatography (LC) techniques with electrospray ionization (ESI) orthogonal acceleration time-of-flight (oa-TOF) mass spectrometry (MS) provides both MS-based structural information and LC-based quantitative data in polymer analysis. In one experimental setup, three different LC modes are interfaced with MS: size-exclusion chromatography (SEC/MS), gradient polymer elution chromatography (GPEC/MS), and liquid chromatography at the critical point of adsorption (LCCC/MS). In SEC/MS, both absolute mass calibration of the SEC column based on the polymer itself and determination of monomers and end groups from the mass spectra are achieved. GPEC/MS shows detailed chemical heterogeneity of the polymer and the chemical composition distribution within oligomer groups. In LCCC/MS, the retention behavior is primarily governed by chemical heterogeneities, such as different end group functionalities, and quantitative end group calculations can be easily made. The potential of these methods and the benefit of time-of-flight analyzers in polymer analysis are discussed using SEC/MS of a polydisperse poly(methyl methacrylate) sample, GPEC/MS of dipropoxylated bisphenol A/adipic acid polyester resin, LCCC/MS of alkylated poly(ethylene glycol), and LCCC/MS of terephthalic acid/neopentyl glycol polyester resin.     

Subattomole-Sensitivity Microchip Nanoelectrospray Source with Time-of-Flight Mass Spectrometry Detection

A microfabricated microfluidic device coupled with a nanospray tip for electrospray ionization of dilute solutions is described. The device has been interfaced with a time-of-flight mass spectrometer and evaluated for sensitive, high-speed detection of peptides and proteins. The electrospray voltage was applied through the microchip to the nanospray capillary that was attached at the end of a microfabricated channel. Fluid delivery rates were 20-30 nL min(-)(1) through the hybridized structure without any pressure assistance. On-line microchip electrophoresis has been demonstrated and the effect of the capillary-chip junction on band broadening examined. Full mass spectra are acquired within 10-20 ms at 50-100 spectra s(-)(1) storage rates. Detection of subattomole levels of sample from a 100 nM solution is demonstrated for infusion experiments.     

Time-of-Flight Mass Spectrometry with a Pulsed Glow Discharge Ionization Source

The pulsed glow discharge (GD) plasma source exhibits several characteristics that make it ideally suited for use with time-of-flight mass spectrometry (TOFMS). TOFMS uniquely affords the ability to monitor a narrow temporal window for a time-varying process such as ion formation in the pulsed glow discharge plasma. Pulsed GD-TOFMS exhibited distinct advantages for the direct determination of trace elements in solid state samples. Initially, the pulse-powered GD-TOFMS system used for these investigations exhibited poor resolution. In an effort to improve resolution, a slit was introduced to narrow the ion beam orthogonally entering the extraction region of the TOFMS. In an effort to determine optimal operating conditions, the influence of slit width on TOF performance was investigated. In the course of this study, the slit width was found to influence isotope ratio accuracy as well as resolution. A slit width of 1.0 mm was determined to provide the best compromise between resolution and isotope ratio accuracy. Pulsed GD-TOFMS affords improved sensitivity and selectivity because Penning ionization is enhanced during the time period immediately following the termination of the discharge power. Ions sampled by an extraction pulse applied after power termination also yield a mass spectrum that is free of contributions arising from electron-ionized interferences. This advantage arises because only ions generated via the Penning ionization mechanism persist after the termination of discharge power. Sampling in the "afterpeak" time regime eliminates the saturation of the detector arising from discharge support gas ion signal.     

猪肉中二溴磷残留量的气相色谱和气相色谱/质谱分析

试样经盐酸酸化,用正己烷提取残留的二溴磷。提取液在-20℃冷冻2小时凝固析出脂肪,净化液经浓缩定容后,用配有电子俘获检测器的气相色谱测定(GC-ECD),外标定量,并用气相色谱—质谱(选择离子监测)(GC/MS(SIM))进行确证。以HP-5大口径毛细管柱和HP-5MS毛细管柱为分离柱,选择出合适的色谱条件,二溴磷的分离效果良好。本方法对猪肉样品的测定低限为0.05mg/kg;添加浓度为0.05mg/kg～1.00mg/kg时,回收率为89％以上;相对标准偏差小于5.0％;标准进样量在0.1～10.0ng范围内,线性关系良好,r=0.9995。样品前处理采用了微量化学法(MiccM)技术,质谱(选择离子监测)确证的监测离子选m/z 301、185、109amu。     

粮谷中嗪草酮残留量的气相色谱和气相色谱-质谱分析

粮谷中嗪草酮残留用苯提取,提取液经浓缩、定容后直接用配有氮磷检测器的气相色谱仪测定,并用气相色谱-质谱(选择离子监测)进行确证。以HP-1大口径毛细管柱和HP-1毛细管柱为分离柱,选择出合适的色谱条件,嗪草酮的分离效果良好。本方法对大米样品的测定下限为0.05mg/kg;添加浓度为0.05mg/kg～1.0mg/kg的嗪草酮,回收率为80％以上;相对标准偏差小于9.5％。样品前处理采用了微量化学法(MiccM)技术,质谱(选择离子监测)确证的监测离子选M/Z103、144、182、198、214amu。     

Laser Time-of-Flight Mass Spectrometry of PAH-Picrate Complexes

The laser desorption/laser ionization time-of-flight (L2ToF), mass spectra of anthracene and the anthracene-picric acid charge transfer (C-T) complex have been compared at a desorption and ionization wavelength of 266 nm. Laser desorption/ionization spectra of anthracene were obtained at low temperatures (-30 °C) to minimize the interference from gas phase ionization. Positive ion mass spectra of the picrate C-T complex at room temperature comprise the parent ion of anthracene and were devoid of signals associated with the picric acid component. The L2ToF analyses of a mixture of volatile and involatile EPA priority PAHs in picric acid show that low molecular weight PAHs form involatile charge transfer complexes. The present method reduces the possibility of volatile PAH loss during mass spectrometric analyses in vacuo.     

配置EI源三重四极杆气相色谱质谱联用仪校准方法研究

讲述了气相色谱-串联质谱联用仪相对于气相色谱-质谱联用仪的优点,通过系统研究及参考JJF1164-2006台式气相色谱-质谱联用仪校准规范,拟定了一套配置电子轰击(EI)源的气相色谱-串联质谱联用仪的校准方法,详述了校准过程。结果数据表明本方法能适用于该类仪器的校准。     

Analysis of Carbendazim in Agricultural Samples by Laser Desorption and REMPI Time-of-Flight Mass Spectrometry

A method has been developed for the analysis of carbendazim in agricultural samples. This has been accomplished by the combination of laser desorption with resonance-enhanced multi-photon ionization (REMPI) coupled to time-of-flight mass spectrometry detection. After the optimization of the experimental conditions and the location of the resonant wavelength of the substance, several samples of pepper extract enriched with carbendazim were analyzed, finding a detection limit of the same order of magnitude as that of current GC and HPLC techniques, but with higher sensitivity and faster sample preparation.