LC/MS/MS法同时测定卷烟主流烟气中4种TSNAs

烟草特有亚硝胺（TSNAs）是存在于、烟草制品和卷烟烟气中的一类有害物质。TSNAs在卷烟烟气中的含量很低,卷烟烟气背景复杂,化学成分达3800多种,卷烟烟气中TSNAs的准确定量难度很大。多年来,TSNAs的测量方法随着分析仪器的进步而不断发展,从薄层色谱到GC、LC,从填充柱到毛细管柱,从FID检测到氮磷检测器检测、热能分析仪检测、质谱检测。     

SPE-LC/MS/MS快速测定卷烟丝中的烟草特有亚硝胺类化合物

建立了卷烟丝中烟草特有亚硝胺类化合物(TSNAs)的SPE-LC/MS/MS分析方法,可一次性对卷烟烟丝中4种TSNAs进行定量分析.该方法弥补了传统的烟丝中TSNAs分析方法样品处理步骤多,检出限高,适应范围窄等缺点.4种TSNA的回收率的范围在95.7%～99.2%之间;相对标准偏差均小于8%;方法检出限均低于1.0 ng/g.可应用于国内外各类型卷烟的分析.     

QuEChERS前处理结合HPLC-Q-TOF/MS非靶向快速筛查凉茶中的非法添加物

建立了QuEChERS法净化,结合高效液相色谱-四极杆-飞行时间质谱法(HPLC-Q-TOF/MS)非靶向快速筛查凉茶中未知非法添加物的方法。凉茶中的非法添加物经0.5%乙酸-乙腈提取,氨丙基粉净化,C_(18)色谱柱(100 mm×2.1 mm,1.7μm)分离,HPLC-Q-TOF/MS测定。利用8种质控化合物建立的筛查方法检出限为2.0～10μg/kg,定量下限为5.0～25μg/kg。3个不同加标水平的平均回收率为75.8%～95.6%,RSD(n=6)为2.1%～6.5%。在该定量方法基础上利用目标化合物特征离子的精确质量数、同位素匹配、二级碎片信息进行数据库匹配,无标准品情况下非靶向筛查非法添加物。结果表明,该方法无需标准品即可快速筛查凉茶中的非法添加西药,能应用于凉茶样品的实际筛查。应用该方法对50份散装凉茶样品进行测定,其中10份凉茶样品检出对乙酰氨基酚,含量为4.14～2 188 mg/kg。该方法快速、准确、分析通量高,可为凉茶中非法添加物的快速筛查和质量控制提供重要依据。     

两种前处理方法对LC - MS/MS测定家兔血清中淫羊藿黄酮类化合物基质效应的影响

考察了两种前处理方法对采用液相色谱-串联质谱联用法( LC - MS/MS)测定家兔血清中淫羊藿黄酮类化合物时基质效应的影响.家兔空白血清分别以乙酸乙酯液-液萃取和C18小柱固相萃取,提取前、后各自加入一定浓度的4种淫羊藿黄酮类化合物的混合对照品溶液(淫羊藿苷、淫羊藿次苷I、淫羊藿次苷Ⅱ、淫羊藿素),评价家兔血清中淫羊...     

高效液相色谱法直接测定血浆中的丝裂霉素C

本实验采用两根反相柱串联而形成的高效液相色谱柱切换装置，直接进样测定血浆中抗癌药物丝裂霉素Ｃ。第一根柱利用胶束流动相进行样品的纯化和富集，第二根柱对药物进行分析。紫外检测波长为３６５ｎｍ。药物的回收率在９５．９％～１００．３％之间，相对标准偏差为２．７６％。用该法对人和狗的局部和全身注射药物的血浆样品进行了测定。     

基于UPLC/Q-TOFMS的大鼠血浆磷脂成分的快速分析

采用超高效液相色谱-四极杆飞行时间高分辨质谱(UPLC/Q-TOF MS)联用技术,对大鼠血浆磷脂提取液进行分析,建立了一种快速、简便、可靠的血浆磷脂鉴别方法。以经典的氯仿甲醇法为磷脂的提取方法,以10 mmol/L甲酸铵水溶液(A)-含10 mmol/L甲酸铵的乙腈-异丙醇(1∶1)混合溶液(B)为流动相,采用ESI源,分别在正、负离子模式下进行数据采集。根据实验结果,结合二级质谱裂解数据、元素组成、数据库匹配,鉴定出81个成分,其中包括7个PE、7个PI和1个SM,其余均为PC。所建立的液相色谱-质谱联用分析方法,可为大鼠血浆中磷脂成分的鉴别提供一种快速、简便、可靠的分析手段,以及为血浆磷脂代谢组学的研究奠定基础。     

LC/MS/MS法测定化妆品中树苔提取物

采用液相色谱-质谱法测定了化妆品中的树苔提取物,建立了化妆品中树苔提取物的检测方法,方法的检出限为10 ng/mL,被测物在10～500 ng/mL范围内线性关系良好.本方法可以用于树苔提取物在化妆品中含量的质量控制.     

LC/MS法分析头孢替坦二钠原料中的杂质

本文应用LC/MS技术对头孢替坦二钠原料中的4种杂质进行了快速鉴定.根据头孢菌素的降解反应机制设计加速实验,确定头孢替坦的2个主要杂质为其碱水解产物;以1%冰醋酸溶液-乙腈-甲醇为流动相,经C18柱分离,通过电喷雾串联质谱负离子检测,获得各杂质的相对分子质量信息和碎片信息,并辅助UV特征对杂质结构进行了鉴定.在所建立的LC/MS条件下,头孢替坦及其杂质得到有效的分离,4个杂质经分析分别为5-巯基-1-甲基-四氮唑、头孢替坦内酯、头孢替坦脱羧物和头孢替坦异构体.本研究表明,利用LC/MS技术可推测头孢菌素类抗生素中杂质的结构,且本方法快速、灵敏、专属性高.     

快速高效液相色谱分离技术在中药分析中的应用

中药化学成分分析是中药药效物质阐明及质量控制的关键问题之一。由于中药化学成分的复杂性,中药成分分析一直存在着分离难度大、分析时间长等问题。为此,针对这些问题发展起来的快速、高效液相色谱技术(主要包括超高压液相色谱、基于整体柱的高效液相色谱和高温液相色谱)备受关注。本文结合本实验室近年的研究,对该技术在中药复杂体系化学成分分析中的应用做简要综述,内容主要包括这些技术的原理、分离性能及其在中药复杂体系中的应用。     

液相色谱-串联质谱法测定地表水中的丙烯酰胺

建立了地表水中丙烯酰胺残留的液相色谱-串联质谱联用测定方法。结果表明,该法的检出限0．1μg,线性范围0．1～100．0μg/L,加标回收率81．7％～86．4％。     

化妆品中碘丙炔醇丁基氨甲酸酯的高效液相色谱检测及质谱确证

建立了高效液相色谱(HPLC)-二极管阵列检测器(DAD)测定化妆品中碘丙炔醇丁基氨甲酸酯的方法.化妆品样品经超声提取后,高效液相色谱-二极管阵列扫描检测,并在235 nm波长进行分析.用保留时间结合紫外光谱定性,外标法定量,并采用液相色谱-质谱法确证.碘丙炔醇丁基氨甲酸酯的回收率为92.7%～99.8%,相对标准偏差在0.8%～2.1%之间,定量限为20 mg/kg.     

Quantification of taraxasterol in rat plasma by LC/MS/MS: application to a pharmacokinetic study

Taraxasterol, a pentacyclic triterpene from Taraxacum officinale, is one of the main active constituents of the herb. This study developed and validated a highly selective and sensitive liquid chromatography/tandem mass spectrometry for the determination of taraxasterol in rat plasma over the range of 9.0–5000 ng/mL. Chromatographic separation was achieved on a C₁₈ (4.6 × 50 mm, 5.0 µm) column with methanol–isopropanol–water–formic acid (80:10:10:0.1, v/v/v/v) as mobile phase with an isocratic elution. The flow rate was 0.7 mL/min. After adding cucurbitacin IIa as an internal standard (IS), liquid–liquid extraction was used for sample preparation using ethyl acetate. The atmospheric pressure chemical ionization source was applied and operated in positive ion mode. Selected reaction monitoring mode was used for the quantification of transition ions m/z 409.4 → 137.1 for taraxasterol and m/z 503.4 → 113.1 for IS. The mean recoveries of taraxasterol in rat plasma ranged from 85.3 to 87.2%. The matrix effects for taraxasterol were between 98.5 and 104.0%. Intra‐ and inter‐day precision were both <11.8%, and the accuracy of the method ranged from ?7.0 to 12.9%. The method was successfully applied to a pharmacokinetic study of taraxasterol after oral administration of 7.75, 15.5 and 31.0 mg/kg in rats. Copyright © 2015 John Wiley & Sons, Ltd.     

Determinations of geniposide using LC/MS/MS methods via forming ammonium and acetate adducts

In this paper, we report method development work to determine geniposide using LC/MS/MS via the formation of positive and negative ion adducts. Geniposide, which has been recognized to have choleretic effects, is the major iridoid glycoside component of Gardenia herbs. To enhance the sensitivity of LC/MS detection of geniposide, a small amount of volatile additives such as ammonium acetate and acetic acid are added into mobile phase solvents to form positive and negative adducts, which can then ionize via electrospray processes. The formation of positive adducts is due to the complexation between geniposide and ammonium ions ([M + NH₄]⁺). The formation of anionic adducts [M + CH₃COO]⁻ is believed to occur via hydrogen bonds bridging acetate ions and glucose groups on the geniposide molecule. Mobile phase solvents containing acetonitrile and aqueous solution (0.2 mM ammonium acetate or 0.1% acetic acid) at the ratio 15: 85 are employed to elute geniposide using C8 reverse phase liquid chromatography columns with electrospray tandem mass spectrometry determinations. Using geniposide standards, the methods are validated at the concentration ranges of 5 to 1000 ng/mL and 20 to 5000 ng/mL using ammonium and acetate adducts respectively. The correlation coefficients of the standard curves are 0.9999 using both ammonium and acetate adducts. The detection limits of using ammonium and acetate adducts are 1 and 5 ng/mL respectively. The measurement accuracy and precision of using ammonium adducts are within 12% and 3% respectively, whereas the accuracy and precision are within 6 and 11% respectively using acetate adducts. When the validated calibration curves of the ammonium adduct of geniposide are used to determine spiked control samples in rat blood dialysates, the determination errors of accuracy and precision are within 12% and 10% respectively.     

Validation and application of a novel LC/MS/MS method for the determination of isoginkgetin in rat plasma

Isoginkgetin is a biflavonoid compound isolated from the leaf extracts of Ginkgo biloba. In this study, an liquid chromatography–tandem mass spectrometry (LC/MS/MS) with liquid–liquid extraction was developed and validated for the analysis of isoginkgetin in rat plasma. In the process of chromatographic separation, selected reaction monitoring transitions for isoginkgetin and IS were m/z 566.8 → 134.7 and m/z 430.8 → 269.3, respectively. The validation parameters including selectivity, linearity, LLOQ, accuracy, precision, matrix effect, stability and recovery were satisfactory. The intra‐ and inter‐batch precision (RSD) were <12.1% in plasma, while the accuracy (RE) was within ±14.3%. This method was employed in a pharmacokinetic study on rats after the intravenous administration of isoginkgetin.     

Applications of LC/MS in structure identifications of small molecules and proteins in drug discovery

With advancements in ionization methods and instrumentation, liquid chromatography/mass spectrometry (LC/MS) has become a powerful technology for the characterization of small molecules and proteins. This article will illustrate the role of LC/MS analysis in drug discovery process. Examples will be given on high-throughput analysis, structural analysis of trace level impurities in drug substances, identification of metabolites, and characterization of therapeutic protein products for process improvement. Some unique MS techniques will also be discussed to demonstrate their effectiveness in facilitating structural identifications.     

Determination of antibacterial agent tilmicosin in pig plasma by LC/MS/MS and its application to pharmacokinetics

A rapid and sensitive high‐performance liquid chromatography–tandem mass spectrometry (LC–MS/MS) method was developed and validated to quantify tilmicosin in pig plasma. Plasma samples were prepared by liquid–liquid extraction. Chromatographic separation was achieved on a C₁₈ column (2.1 × 30 mm, 3.5 μm) using acetonitrile–water (90:10, v /v; water included 0.1% formic acid) as the mobile phase. Mass detection was carried out using positive electrospray ionization in multiple reaction monitoring mode. The calibration curve was linear from 0.5 to 2000 ng/mL (r ² = 0.9998). The intra‐ and inter‐day accuracy and precision were within the acceptable limits of ±10% for all tilmicosin concentrations. The recoveries ranged from 95 to 99% for the three tested concentrations. The LC–MS/MS method described herein was simple, fast and less laborious than other methods, achieved high sensitivity using a small sample volume, and was successfully applied to pharmacokinetic studies of tilmicosin enteric granules after oral delivery to pigs. In comparison with tilmicosin premix, tilmicosin enteric granules slowed the elimination rate of tilmicosin, prolonged its period of action and significantly improved its bioavailability.     

Recently developed GC/MS and LC/MS methods for determining NSAIDs in water samples

Pharmaceuticals have become major targets in environmental chemistry due to their presence in aquatic environments (following incomplete removal in wastewater treatment or point-source contaminations), threat to drinking water sources and concern about their possible effects to wildlife and humans. Recently several methods have been developed for the determination of drugs and their metabolites in the lower nanogram per litre range, most of them using solid-phase extraction (SPE) or solid-phase microextraction (SPME), derivatisation and finally gas chromatography mass spectrometry (GC-MS), gas chromatography tandem mass spectrometry (GC-MS/MS) and liquid chromatography electrospray tandem mass spectrometry (LC-ES/MS/MS). Due to the elevated polarity of non-steroidal anti-inflamatory drugs (NSAIDs), analytical techniques based on either liquid chromatography coupled to mass spectrometry (LC-MS) and gas chromatography coupled to mass spectrometry (GC-MS) after a previous derivatisation step are essential. The most advanced aspects of current GC-MS, GC-MS/MS and LC-MS/MS methodologies for NSAID analysis are presented.     

Simultaneous analysis of 35 specific antihypertensive adulterants in dietary supplements using LC/MS/MS

A sensitive and specific LC/MS/MS method was developed for the simultaneous analysis of 35 compounds used for treating hypertension as adulterants in dietary supplements. The method was validated for specificity, linearity, accuracy, precision, limit of detection, limit of quantitation, stability and recovery. The limit of detection and limit of quantitation ranged from 0.20 to 20.0 and 0.50 to 60.0 ng/g, respectively. The linearity was good (r ² > 0.999), with intra‐ and interday precision levels of 0.43–7.87% and 0.65–9.95% and the intra‐ and interday accuracies of 84.36–115.82% and 83.78–118.69%, respectively. The stability (relative standard deviation) was <14.75%. The mean recovery was 80.81–117.86% (relative standard deviation <10.00%). Ninety‐seven commercial dietary supplements available in South Korea were analyzed. While none contained detectable amounts of the 35 antihypertensive compounds, the developed LC/MS/MS procedure can be used for routine analysis to monitor illegal adulteration in various forms of dietary supplements.