气相色谱-质谱联用法测定烟用香精中黄樟素及香豆素

采用气相色谱-质谱(GC-MS)联用分析技术,提出了烟用香精中香豆素、黄樟素的同时测定方法。色谱柱为DB-1 MS石英毛细管柱,电子轰击离子源,选择香豆素质谱图中m/z89,90,118,146;黄樟素m/z104,131,135,162各4个特征离子用于选择离子检测法检测,根据这4个离子的抽出离子色谱图的峰面积比进行目标物确证,以基峰m/z118,162作两成分的定量分析,方法的检出限(3S/N)均为0.1 mg.kg-1。用色谱保留时间、质谱特征离子同时定性,消除了香精样品中复杂基体的干扰,避免了假阳性结果的出现。     

同位素稀释高分辨气相色谱-高分辨质谱法检测烟道气中的低氯代二恶英

建立了同位素稀释高分辨气相色谱-高分辨质谱检测烟道气中痕量低氯代二恶英的分析方法。采用索氏提取富集烟道气样品中的目标物,提取液经过复合硅胶柱和碱性氧化铝柱净化后,进行高分辨气相色谱-高分辨质谱检测。采用DB-5MS毛细管色谱柱（30 m×0.25 mm×0.25 μm）分离,以保留时间和同位素特征离子丰度比定性,以与同位素的峰面积比值定量。实验结果表明,方法的回收率为66.6%~112.5%,相对标准偏差（RSD）的范围为19.9%~40.5%（n=5）,方法的检出限（LOD）为0.027~0.485 μg/L。应用该方法检测了3个焚烧炉烟道气样品,回收率在85.7%~137.0%范围内,样品中目标物含量分布在11.4~9183 pg/Nm³之间。结果表明该方法适合用于烟道气中痕量低氯代二恶英的检测。     

气相色谱–质谱法测定白酒中的邻苯二甲酸酯类

采用气相色谱–质谱法对常见名贵白酒中的16种邻苯二甲酸酯类含量进行测定。将样品提取、净化后,经气相色谱–质谱联用仪进行分离测定。采用特征选择离子检测扫描(SIM),以色谱保留时间和色谱碎片的丰度比定性,以峰面积外标法定量。16种邻苯二甲酸酯类物质的含量与色谱峰面积在0~2.0μg/m L范围内线性良好,线性相关系数均在0.995以上,方法检出限为0.05 mg/L。16种邻苯二甲酸酯含量测定结果的相对标准偏差均小于10%(n=6),加标回收率为91.21%~105.22%。该方法样品前处理简单,灵敏度高,适用于同时定性及定量检测白酒中16种邻苯二甲酸酯。     

高脂肪食品中合成着色剂的检测

建立了高脂肪食品中合成着色剂的高效液相色谱检测方法。在碱性溶液中用正己烷萃取食品中的脂肪,分层后移除脂肪层,从剩余溶液中提取的柠檬黄、苋菜红、靛蓝、胭脂红、日落黄、诱惑红、亮蓝七种水溶性合成着色剂经高效液相色谱分离后,用二极管阵列检测器(DAD)检测,与标准溶液的保留时间、吸收光谱的特征及峰面积比较进行定性、定量;在优化的萃取pH值与色谱分析条件下,平均回收率在92.8%~102.1%之间,检出限为0.1 mg/kg。该法前处理简单,回收率高,操作简便,测定结果令人满意。     

高效液相色谱法测定着色剂食品黄3中6种磺酸类杂质

建立了高效液相色谱法测定着色剂食品黄3中6种磺酸类杂质的分析方法.采用纯水超声提取样品,以乙腈-四丁基溴化铵水溶液为流动相,经Agilent ZORBAX SB-C18(4.6 mm×250 mm,5μm)色谱柱分离后,用二极管阵列检测器(DAD)进行检测.以保留时间和紫外吸收光谱定性,外标法定量.6种磺酸类杂质在相应...     

移动子窗口中搜索法在紫丁香挥发油气相色谱-质谱分析中的应用

基于气相色谱-质谱仪产生的二维数据,采用移动子窗口搜索法,以纯组分峰为标准对同一样品在不同色谱柱上或不同样品在相同色谱柱上所获得的总离子流图的一定保留时间范围内搜索,可以得到目标化合物的流出区域,取其中点作为保留时间,从而计算各化合物在不同极性色谱柱上的程序升温保留指数.采用GC-MS与色谱保留指数相结合的方法,分别在HP-5MS和DB-35MS柱上,于80℃～290℃(4℃/min)的升温程序下,对黑龙江产紫丁香花蕾与花挥发油的分析结果表明,辅以化学计量学方法和双柱色谱保留指数定性比单用GC-MS定性结果更加快速可靠.     

高效液相色谱-二极管阵列检测器同时测定化妆品中的九种染料及中间体

建立了用高效液相色谱-二极管阵列检测器(HPLC-PDA)同时检测9种染料及中间体的系统方法。首先采用超声提取的方法处理样品,对提取溶剂和提取时间进行了选择,确定用甲醇-0.01 mol/L 乙酸铵(体积比为2∶1)作提取溶剂,超声提取20 min。然后,采用C18柱,以甲醇-0.01 mol/L乙酸铵(pH 6.2)为流动相梯度洗脱,用PDA检测。以保留时间定性,并以紫外吸收光谱图辅助定性,以外标法定量。定量检测波长为230 nm,15 min内可对9种目标物同时进行测定,且各化合物都达到基线分离(分离度大于1.5)。经测定,该方法的平均回收率(n=8)为81.0%～105.6%,相对标准偏差（RSD）为0.8%～4.9%,检出限(以信噪比为3计)为0.1～2 μg。该方法简单、快速,能有效提取和分离测定化妆品中9种染料及中间体。将该方法用于实际化妆品样品的检测,结果令人满意。     

在线样品制备技术耦合液相色谱-质谱系统在食品危害物检测中的应用进展

食品安全检测具有重要意义,但食品样品基质复杂,测定其中危害物时,通常需要以下几个步骤：样品制备,即采用适合的样品前处理方法,在不同基质中将目标物分离出来;分离纯化,利用色谱系统进一步分离纯化目标物;定性定量分析,基于目标化合物的性质选择合适的检测器进行分析。其中样品制备是关键步骤之一,将样品制备过程与液相色谱系统耦合可以实现样品的在线自动化分析。与传统人工处理过程相比,在线分析不仅能够减少人工操作误差,保证良好的精密度和重复性,而且可以降低溶剂消耗,避免样品间交叉污染,同时节约分析时间,提高检测效率。本文主要介绍目前常用的在线样品制备技术,包括在线固相萃取(on-line SPE)、管内固相微萃取(in-tube SPME)、湍流色谱法(TFC),详细阐述了其基本原理和耦合设备。在线样品制备技术耦合液相色谱-质谱系统分为两个维度,主要依赖于阀切换技术,将样品制备(第一维度)和液相色谱系统(第二维度)之间建立物理连接,随后采用相应的检测器进行分析。第一维度的作用主要是去除样品杂质,净化分离目标物,为第二维度对目标物进行定性定量检测做准备。此外,文章对3种在线净化系统适用的不同净化填料进行...     

移动子窗口搜索法在紫丁香挥发油气相色谱-质谱分析中的应用

基于气相色谱-质谱仪产生的二维数据，采用移动子窗口搜索法，以纯组分峰为标准对同一样品在不同色谱柱上或不同样品在相同色谱柱上所获得的总离子流图的一定保留时间范围内搜索，可以得到目标化合物的流出区域，取其中点作为保留时间，从而计算各化合物在不同极性色谱柱上的程序升温保留指数。采用GC-MS与色谱保留指数相结合的方法，分别在HP-5MS和DB-35MS柱上，于80℃～290℃（4℃／min）的升温程序下，对黑龙江产紫丁香花蕾与花挥发油的分析结果表明，辅以化学计量学方法和双柱色谱保留指数定性比单用GC-MS定性结果更加快速可靠。     

气相色谱-飞行时间质谱快速鉴定和定量测定烟草中43种农药

建立了烟草中43种农药的气相色谱-飞行时间质谱(GC-TOF MS)分析方法。采用改进的Qu EChERS前处理方法,样品以丙酮-正己烷(1∶1)进行萃取,萃取液经N-丙基乙二胺(PSA)吸附剂分散固相萃取净化后,用GC-NCI-TOF MS进行检测。通过高分辨飞行时间质谱的精确质量数测定,建立了农药的特征离子数据库,结合目标物保留时间、碎片离子的丰度比、裂解规律、同位素离子峰簇等进行目标物定性鉴定。配制基质匹配标准曲线,以磷酸三苯酯(TPP)为内标进行定量测定。43种农药的线性相关系数(r2)均不小于0.993,相对标准偏差不大于9.6%,定量下限为1.3~5.0μg/kg;在3个水平下的加标回收率为76.4%~96.6%。该方法简单快速,准确性和灵敏度高,满足烟草中多农药残留的定性和定量检测要求。     

中药川芎和赤芍配伍规律的方法研究

提出应用HPLC-PAD-MS研究中药配伍多种化学成分的基本思路,指出应用色谱保留时间、紫外光谱及质谱等多信息、综合对照的方法确定合煎液中各峰的归属,从而进一步研究了中药的配伍规律.首先建立了一套稳定、重复而可靠的液相色谱分析方法进行分离,再用统一的分析方法对分离的色谱图进行数据处理.在HPLC-PAD-MS分析中可得到各成分的保留时间、紫外光谱和分子量信息.通过比较合煎液和单煎液中各成分的保留时间及分子量信息可确定合煎液各峰的归属,最后比较了单煎液和合煎液的化学成分变化.结果表明,川芎和赤芍配伍后有一新峰产生,同时有两个成分含量发生变化.     

Simultaneous Qualitative Analysis of Coumarins in the Rhizome of Angelica polymorpha Maxim. by LC?CDAD?CESI?CMS

A novel method has been developed for simultaneous qualitative analysis of coumarins in the rhizome of Angelica polymorpha Maxim. with the use of high-performance liquid chromatography (LC)?Cphotodiode array detection (DAD)?Celectrospray ionization (ESI)?Ctandem mass spectrometry (MS). LC analysis was performed on an Agilent Eclipse XDB-C₁₈ analytical column with a gradient solvent system of water and methanol, ultraviolet (UV) absorption detection was at 300?nm and peak UV spectrum and (+) ESI?CMS data were acquired by DAD and a quadrupole mass spectrometer, respectively. Eight peaks were identified as linear furocoumarins including aviprin, isopimpinellin, bergapten, isooxypeucedanin, gosferol, imperatorin, phellopterin and isoimperatorin by comparing their retention time, UV, and MS spectra with that of the authentic standards, and the analysis of UV spectra and ESI?CMS data of the standards gave the characteristics of UV absorption and ESI?CMS fragmentation. On the basis of the above characteristics, the possible structures of four other linear furocoumarins were deduced in LC. The other chemical structures were proposed as three angular furocoumarins, a simple coumarin, two chromones, and a cinnamic acid by comparing their UV and MS data with that of literature reports. Accordingly, the method we established can simply and accurately identify the key chemical constituents in the rhizome of A. polymorpha.     

GC/MS中保留指数和保留温度回归分析应用于单萜烯结构确认

GC／MS定性分析中,由于同分异构体的质谱图相似,常常出现结构鉴定错误．同分异构体化合物的保留行为具有较大地差别,采用文献保留指数和保留温度测定值回归分析方法对2篇已发表论文进行了研究,发现了对单萜烯类同分异构体结构鉴定中存在的错误,并提出可能的正确结构．文献保留指数和保留温度测定值回归分析方法可以简化GC／MS色谱峰的定性分析过程,提高定性分析的准确性,在样品定性分析中具很强的使用价值．     

Fingerprint Analysis of Euonymus alatus (Thuhb) siebold by LC–DAD and LC–ESI–MS

A liquid chromatography coupled with photodiode array detection and electrospray ionization tandem mass spectrometry method was first developed for a chemical fingerprint analysis of Euonymus alatus (Thuhb) siebold (EAS) and rapid identification of major compounds in the fingerprints. Fingerprint profiles were found to be consistent for the herbs acquired from different locations, but the relative abundance of peaks was varied. Twelve peaks were chosen as the common peaks. Quercetin and rutin were detected by comparing the retention times, MS and UV spectra with the standards. The relative retention time and relative peak area of the 12 peaks in the fingerprint were calculated by setting the quercetin as the reference peak. The experimental data were used for similarity calculation and hierarchical clustering analysis. By comparing the UV and MS spectra data with those of the authentic standards and literature, five main peaks in the fingerprints were identified. Finally, five medicinal portions of the herb (leaf, fruit, stem, pterygium and root) were also analyzed by this method. It was found that there were similar chemical components in different parts of this herb but the contents were very different. The developed fingerprint assay was specific and could be readily utilized for comprehensive evaluation of EAS, as well as to distinguish different medicinal portions.     

Development of high-performance liquid chromatographic fingerprint for the quality control of Rheum tanguticum Maxim. ex Balf

A novel, accurate and valid fingerprint method was developed by using high-performance liquid chromatography-photodiode array detection (HPLC-DAD) to control the quality of Rheum tanguticum Maxim. ex Balf. By comprehensively comparing chromatograms of all samples, our result revealed that the chromatographic fingerprint we developed combining similarity evaluation could efficiently identify and distinguish raw materials of R. tanguticum from different sources. Besides, 21 characteristic peaks in chromatogram of R. tanguticum were unambiguously confirmed by comparison of reference compounds based on their retention time (t(R)) and UV spectra.     

气相色谱-单光子电离飞行时间质谱的联用及在柴油组分表征中的应用

建立了一种气相色谱(GC)与单光子电离-飞行时间质谱(SPI-TOF MS)联用(GC/SPI-TOF MS)的分析方法。首先,设计了一种双层套管的传输管用于连接GC与SPI-TOF MS,实现了GC与单光子电离离子源的无缝连接。在此基础上,以n-十五烷标准品和苯/甲苯/二甲苯的标准气为对象,对电离源的重要电压参数进行了优化,得到了纯净的分子离子峰,实现了对各类有机物的快速和准确定性。最后,将该方法用于分析柴油中的挥发性与半挥发性有机物,获得了柴油组分的二维GC×SPI-TOF MS谱图。不需要复杂的谱图解析和数据处理,根据谱图中离子的质荷比(m/z)归纳了柴油的主要成分,包括脂肪烃、芳香烃和含量很低的苯并吡咯等含氮化合物;根据色谱的保留时间将柴油中的同分异构体区分开来。结果表明GC/SPI-TOF MS法是一种简单、有效的分析方法,非常适于柴油及复杂环境样品等的分析表征。     

A novel collagenase-assisted extraction of active pharmaceutical ingredients from gelatin products for quantitative analysis by high performance liquid chromatography

High performance liquid chromatography (HPLC) is frequently used for quantifying drugs in gelatin capsules. Gelatin has a strong UV absorption that often overlaps with drug absorbances. Therefore, the gelatin capsules must be removed manually before analysis. This study describes a novel extraction method named collagenase-assisted extraction (CAE), which uses collagenase to degrade gelatin into fragments with reduced hydrophobicity, allowing gelatin-related peaks to elute immediately, eliminating interference with the drug peak and enabling use of whole gelatin capsules during drug quantification. Use of CAE eliminates powder loss when opening a gelatin capsule, allows extraction of drugs from the capsule, reduces analytical time, and extends HPLC column life.     

Quality assessment of Fructus xanthii based on fingerprinting using high-performance liquid chromatography

Because almost every traditional Chinese medicine (TCM) is a multicomponent system, QC of TCMs always involves various difficulties. As a current popular quality assessment approach, focusing on qualitative and quantitative analysis of certain compounds contained in herbal medicine has been widely used for the sake of expediency rather than being a practical and realistic way. However, this method does not take the existence of other constituents into account. Comparatively, the chromatographic fingerprint of the components is a more suitable approach to holistically assess the quality of herbal drugs. Fructus xanthii is a well-known herbal drug listed in all editions of the Chinese Pharmacopoeia. However, there is no quality evaluation method given in its monograph, even for the above-mentioned expediency. This paper reports an HPLC fingerprinting method for quality evaluation of F. xanthii. The HPLC profiles of 27 batches of commercial samples were further analyzed using chemometric methods, including similarity evaluation and principal component analysis. As a result, the established HPLC fingerprint contained 23 characteristic peaks; therein, 13 peaks were unambiguously assigned by comparing their retention times and UV spectra with those of reference compounds, and five peaks were tentatively identified on the basis of their MS/MS fragmentation patterns and UV spectra. Moreover, it could be clearly observed that caffeoylquinic acid and its analogs predominate in F. xanthii. Except for three samples identified as outliers, 24 other commercial samples displayed similar HPLC profiles, indicating that the quality of the herbs from different markets is stable and consistent.     

Computerized separation of chromatographically unresolved peaks

A computerized peak deconvolution software and mass spectra were successfully applied for the deconvolution of overlapped peak cluster in the chromatogram obtained separating the complex mixture of pesticides by retention time locking gas chromatography-mass spectroscopy. The method based on the unique fragment ions in the spectra can be used for deconvolution of peak clusters if mass spectra of overlapped peaks differ. This method allows determining actual retention times of overlapped peaks. Peak areas found by this method however, cannot be used naturally for the quantitative purposes as the abundance of fragment ions used for this deconvolution procedure can dramatically differ. Computer assisted deconvolution of peaks in the peak clusters gives more realistic peak area ratios as at this method it is supposed equal response for all peaks overlapped in a cluster.     

Fingerprint developing of coffee flavor by gas chromatography-mass spectrometry and combined chemometrics methods

In this paper, chromatographic fingerprint was firstly used for quality control of tobacco flavors. Based on gas chromatography-mass spectrometry (GC-MS) and combined chemometrics methods, a simple, reliable and reproducible method for developing chromatographic fingerprint of coffee flavor, one of tobacco flavors, was described. Six coffee flavor samples obtained from different locations were used to establish the fingerprint. The qualitative and quantitative analysis of coffee flavor sample from Shenzhen was completed with the help of subwindow factor analysis (SFA). Fifty-two components of 68 separated constituents in coffee flavor sample from Shenzhen, accounting for 88.42% of the total content, were identified and quantified. Then, spectral correlative chromatography (SCC) was used to extract the common peaks from other five studied coffee flavor samples. Thirty-eight components were found to exist in all six samples. Finally, the method validation of fingerprint analysis was performed based on the relative retention time and the relative peak area of common peaks, sample stability and similarity analysis. The similarities of six coffee flavor samples were more than 0.9104 and showed that samples from different locations were consistent to some extent. The developed chromatographic fingerprint was successfully used to differentiate coffee flavor from coco flavor and some little difference sample prepared with coffee flavor and coco flavor by both similarity comparison and principal component projection analysis. The developed method can be used for quality control of coffee flavor.