土壤和沉积物中5种苯胺类化合物的测定——超高效液相色谱-串联质谱法

本方法通过超声波萃取方式提取土壤中的5种苯胺类化合物(苯胺、对-甲基苯胺、对甲氧基苯胺、间甲基苯胺、邻甲基苯胺),经离心、净化、浓缩、定容后,利用超高效液相色谱-串联质谱法进行分离、测定,内标法定量。该方法具有较高灵敏性及良好的精密度,加标回收率范围为91.1%-111%,回收率较好,方法检出限为0.38-0.54μg/kg,测定下限为1.5-2.2μg/kg。可应用于实际的监测工作中。     

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.     

基质辅助激光解吸/电离质谱质量分析器技术综述

基质辅助激光解吸/电离质谱(MALDI-MS)作为一种软电离质谱分析技术,具有灵敏度高、操作简单、适用范围广等特点,可以用于常规离子化方法较难电离样品分析,目前已被广泛应用于蛋白质、多肽、低聚核苷酸、低聚糖、合成聚合物等的分析。近年来MALDI-MS仪器技术有了较大进展,本文主要从MALDI-MS的基本原理、仪器技术研究进展方面进行了综述,对基质辅助激光解吸/电离离子源与多种质量分析器的串联研究进行了讨论。     

Study of the Theophylline Content of Single Coated Particles by Gas Chromatography/Mass Spectrometry

The aim of the present study was to determine by gas chromatography/mass spectrometry (GC/MS) the content uniformity of single theophylline microcapsules of different particle size ranges. Microencapsulation was carried out in a laboratory fluidized bed system using Eudragit L30D aqueous dispersion. Scanning electron microscopy was applied for the characterization of the surface morphology of the prepared theophylline microcapsules of two different particle size ranges. The theophylline content of single particles was determined by GC/MS analysis. It was found that the particle size of microcapsules greatly influenced their theophylline content. The GC/MS analysis was successfully applied to indicate the changes in the content uniformity and thus the interparticular coating distribution of single theophylline microcapsules in the presence of several excipients.     

Study of the Theophylline Content of Single Coated Particles by Gas Chromatography/Mass Spectrometry

The aim of the present study was to determine by gas chromatography/mass spectrometry (GC/MS) the content uniformity of single theophylline microcapsules of different particle size ranges. Microencapsulation was carried out in a laboratory fluidized bed system using Eudragit L30D aqueous dispersion. Scanning electron microscopy was applied for the characterization of the surface morphology of the prepared theophylline microcapsules of two different particle size ranges. The theophylline content of single particles was determined by GC/MS analysis. It was found that the particle size of microcapsules greatly influenced their theophylline content. The GC/MS analysis was successfully applied to indicate the changes in the content uniformity and thus the interparticular coating distribution of single theophylline microcapsules in the presence of several excipients.     

Laser Vaporization/Ionization Interface for Capillary Electrophoresis-Time-of-Flight Mass Spectrometry

Mass spectrometry (MS) is usually coupled on-line with capillary electrophoresis (CE) to analyze biomolecules by using electrospray ionization or continuous-flow fast-atom bombardment. We present a new design for laser vaporization/ionization time-of-flight mass spectrometry. CE, with its low flow rate (<1 μL/min), is highly compatible with MS, even if the total column effluent is introduced directly. A UV laser is used to vaporize and ionize the solution eluting from the column. There is no need to have a makeup solvent. Using this system, we have analyzed a group of amines and peptides. The concentration detection limit of serotonin is in the 10(-)(7) M level. The separation and identification of an amine mixture by CE/MS demonstrates the complementary nature of the information.     

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.     

液相色谱质谱联用仪的使用和保养

液相色谱质谱联用仪因其分析范围广、分离能力强、检测限低、分析快速等优点在生物、医药、化学、化工、环境等学科得到了广泛的应用。本单介绍了液相色谱质谱联用仪的原理、种类及应用范围,着重介绍了液相色谱质谱联用仪在使用及维护保养的要点和注意事项,以及校准仪器的方法。     

三重串联四级杆液质联用仪检测糖果中三聚氰胺

本文建立了高效液相色谱串联质谱检测糖果中三聚氰胺的方法。以糖果为基质,采用三氯乙酸水溶液超声提取目标分析物,提取液经过离心、净化处理后,用强阳离子交换与反相C18混合填料色谱柱分离,乙腈和l0mmol/L乙酸铵作为流动相(1:1),用串联质谱在多级反应监测模式下定量检测。LC-MS/MS定量限为0.01mg/kg,线性范围为10～500μg/L,相关系数r20.99,平均回收率为66.8%～98.7%,相对标准偏差为1.9%～7.6%(n=6)。     

液相色谱-串联质谱法测定茶叶中24种农药残留

本文建立了液相色谱-串联质谱法(LC-MS/MS)快速检测茶叶中24种农药残留的分析方法。样品经含0.1%乙酸的乙腈提取,经无水硫酸镁、石墨化碳黑吸附剂(GCB)、N-丙基乙二胺(PSA)净化,以电喷雾电离正离子(ESI+)、多反应检测模式(MRM)进行检测,外标法定量。24种农药在0.005~0.10 mg/kg范围内线性相关系数均大于0.99。该分析方法简便、快速,通过优化前处理和上机条件,在最优条件下进行测试,方法定量下限(S/N>10)为0.01 mg/kg,方法回收率为67%~99%,相对标准偏差(RSD)为3.0%~10.3%。该方法适用于茶叶中常用农药同时检测。     

策划药物MDPV的检验

本文建立了策划药物亚甲基二氧吡咯戊酮(MDPV)的气相色谱-质谱(GC-MS)联用、液相色谱-质谱(LCMS)联用分析方法。利用GC-MS联用、LC-MS联用分析技术对MDPV进行分析,得到MDPV的GC-MS分析主要特征离子及LC-MS联用分析分子离子峰、二级质谱碎片峰、三级质谱碎片峰,并对各特征离子及碎片峰进行了归属研究,得到了MDPV的GC-MS联用、LC-MS联用分析的质谱裂解规律及特征离子。     

液相色谱/串联质谱法测定茄子中5种拟除虫菊酯类农药残留

建立了茄子中5种拟除虫菊酯类农药(氟氰戊菊酯、甲氰菊酯、氯氟氰菊酯、溴氰菊酯和氟胺氰菊酯)残留的液相色谱/串联质谱检测方法。样品以乙腈提取,采用电喷雾正离子源(ESI+)和多重反应监测(MRM)模式测定,基质匹配标准曲线定量。结果表明:茄子基质中,5种拟除虫菊酯类农药峰面积响应值与其质量浓度呈良好线性关系(r0.995)。氟氰戊菊酯、甲氰菊酯、氯氟氰菊酯、溴氰菊酯和氟胺氰菊酯检测方法线性范围分别为8~100μg/L、2~100μg/L、10~100μg/L、4~100μg/L和4~100μg/L,检出限分别为2.52、0.63、3.14、1.26和1.13μg/kg,定量限分别为8.4、2.1、10.4、4.2和3.7μg/kg;5、50和100μg/kg三个添加水平下,5种拟除虫菊酯类农药的回收率在71.7%~91.1%,相对标准偏差为4.9%~9.3%。该法简单、准确、快速、灵敏,符合法规残留限量监测要求。     

Formation of High Mass Cn clusters (n > 100) by Laser Ablation/Desorption Coupled with Mass Spectrometry

Abstract

The “in-situ” formation of high mass carbon C_n clusters (n>100) is studied by laser irradiation of the fullerenes C₆₀, C₇₀, C76 and C₈₄ in a Laser Microprobe coupled with Mass Spectrometry (LMMS).The fragmentation of the fullerene by loss of C₂ units and the distribution of the obtained coalescence products are strongly depending on the laser power density and the wavelength. This phenomenum is correlated to the reactivity of the C₂ fragments.     

超高效液相色谱串联质谱法检测甘蔗中多种农药残留

针对甘蔗种植过程中常用的几种农药,采用分散固相萃取为前处理手段,建立了超高效液相色谱串联质谱法同时检测多菌灵、呋喃丹、乐果、敌敌畏、敌百虫的方法。甘蔗样品经粉碎后用乙腈超声提取,上清液经Qu EChERS方法净化后,采用UPLC-MS/MS法检测分析,外标法定量。结果表明,5种农药残留在1.0~50.0ng/m L的范围内具有良好的线性关系,其检出限为0.12~0.83μg/kg。方法的平均加标回收率为86.7%~106.8%,相对标准偏差为1.6%~4.3%(n=6)。该方法具有操作简单、快速高效、灵敏度高的优,能有效应对甘蔗种植过程中不同种类农药的同时检测。     

全自动固相萃取/超高效液相色谱串联质谱法检测食品中的9种合成色素

建立了超高效液相色谱串联质谱法检测食品中柠檬黄、苋菜红、胭脂红、日落黄、亮蓝、新红、靛蓝、诱惑红、赤鲜红9种合成色素的快速检测方法。采用反相-弱阴离子交换固相萃取小柱,在Labtech的Speline全自动固相萃取平台上实现对样品的连续、自动化处理过程,极大地提高了工作效率。净化液经Agilent XDB C18色谱柱,以甲醇和10mmol/L乙酸铵溶液为流动相梯度洗脱,6min内实现基线分离。采用电喷雾正离子模式（ESI＋）电离,多反应监测（MRM）模式定量检测。9种合成色素的质量浓度在10-500μg/L的范围内与其响应值呈线性关系,其检出限（3S/N）在0.009-0.044mg/kg之间。将该方法应用于食品中合成色素的测定,其回收率范围为88.8%-108.2%,相对标准偏差（n=6）均小于5%。该方法高效、快速、准确,可满足批量化检测的需求。     

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.     

液相色谱-串联质谱法检测鸡肉中7种糖皮质激素残留量

建立鸡肉中糖皮质激素多残留的液相色谱-串联质谱分析方法。样品经乙酸乙酯提取,正己烷净化,10%乙腈水定容后供高效液相色谱-串联质谱仪(LC-MS/MS)分析,采用C18色谱柱分离,电喷雾离子化负离子方式(ESI-)及多反应监测模式(MRM)进行测定,外标法定量。研究了仪器条件、提取溶剂、净化溶剂等条件对七种目标物分离状况的影响。在优化条件下,该方法在鸡肉样品中泼尼松的的线性范围为0.5~20μg/L,泼尼松龙、甲基泼尼松、地塞米松、氢化可的松、倍氯米松、氢化可的松乙酸盐的浓度范围为0.1~20μg/L,在加标水平1.0~10μg/kg范围内,回收率为83%~104.2%;相对标准偏差为0.92%~4.89%。     

液相色谱-质谱联用检测环境水样中刚果红染料

本文探讨了采用液相色谱-电喷雾质谱法检测环境水样中刚果红染料的方法。流动相为甲醇:水=70:30,色谱柱为ZorbaxXDB-C18(150×4.6 mmid,5μm),流速为0.6 ml·min-1。刚果红的准分子离子为m/z325,方法的检出限为0.1 mg·l-1,线性范围为0.4～100 mg·l-1,相关系数r为0.9915,相对标准偏差范围为8.5%～13.4%,样品的回收率为83.5%～106.4%。该法快速、灵敏度高、重现性好。     

固相萃取-超高效液相色谱-串联质谱法测定花生中10种农药残留

建立了花生中10种农药残留的快速分析方法。样品用乙腈水均质提取,盐析分配,提取液经Envi-18和LC-NH2复合固相萃取小柱净化后供超高效液相色谱-串联质谱仪(UPLC-MS/MS)分析,电喷雾离子化正离子方式(ESI+)及多反应监测模式(MRM)进行测定,基质匹配标准溶液外标法定量。在最优条件下进行测试,所测项目方法的定量限(S/N≥10)均小于0.01 mg/kg。在加标水平为0.01 mg/kg、0.05 mg/kg和0.20 mg/kg时,方法回收率为71.1%～112%,相对标准偏差为4.5%～17.8%。     

超高效液相色谱-串联质谱法测定水产品中三聚氰胺残留量

本文建立超高效液相色谱-串联质谱(UPLC-MS/MS)快速测定水产品中三聚氰胺残留的方法。色谱条件:ACQUITY UPLC BEH HILIC柱(2.1×100 mm,1.7m),流动相:乙腈-0.5 mmol/L乙酸铵溶液(0.1%甲酸),流速:0.3mL/min。采用电喷雾质谱检测,以正离子模式5min就完成了质谱分析。实验结果表明,三聚氰胺在水产品中的检测限为0.05 mg/kg,在0.05~0.50 mg/kg添加水平时加标回收率为63%~90%之间,相对标准偏差(RSD,n=6)均小于7.2%。