Determination of sterols in tobacco leaves by gas chromatography-tandem mass spectrometry

The purpose of the study was to establish an analytical method to simultaneously determine multiple sterols in tobacco leaves rapidly and accurately.In this gas chromatography-triple quadruple tandem mass spectrometry(GC-MS/MS)based method,various conditions for sterols extraction were assessed and the instrumental operation parameters were optimized with 5α-cholane as an internal standard.Using this method,eight plant sterols,namely lanosterol,campesterol,chenodeoxycholic acid,cholesterol,β-sitosterol,stigmasterol,dihydrotachysterol and ergosterol,were separated in less than 30 min.The linear correlation coefficients were over 0.998 9,the low detection limits were in the range of 0.010 3-0.141 4 μg/g.The recoveries were from 87.30% to 115.60%,with low standard deviations.In conclusion,this method demonstrates good repeatability,accuracy,and high sensitivity,and is best suited for rapid analysis of multiple sterols in tobacco leaves.

The Detection of THCA Using 2-Dimensional Gas Chromatography-Tandem Mass Spectrometry in Human Fingernail Clippings: Method Validation and Comparison with Head Hair

Marijuana use as well as abuse is a significant public health and public safety concern in the United States and using hair to identify marijuana users and abusers has been gaining acceptance in a number of venues including workplace, court ordered, and substance abuse treatment monitoring. After the presentation of a fully validated 2-dimensional gas chromatography-tandem mass spectrometry method for the detection of 11-nor-9-carboxy-Δ9-tetrahydrocannabinol (THCA), the chief metabolite of the main psychoactive compound in marijuana, Δ9-tetrahydrocannabinol (THC), we evaluated the usefulness of fingernail clippings as an alternative specimen type to hair by the analysis of a set of 60 matched pairs of head hair and fingernail clippings. The limit of detection was 10 fg/mg, the limit of quantitation was 20 fg/mg, and the assay was linear from 20 fg/mg to 500 fg/mg. The intra- and inter-assay imprecision and bias studies at 4 different concentrations (50, 100, 500, and 1000 fg/mg) were acceptable where all % Target observations were within 16% of their expected concentrations and all %CV calculations were less than 13.5%. THCA was detectable in more fingernail specimens (53.3%) than hair specimens (46.7%) and the mean concentrations in nails were on average 4.9 times higher than in hair (1813 fg/mg and 364 fg/mg, respectively). The THCA concentrations in hair and nail were strongly associated (r = 0.974, P < 0.01, n = 60) and the association was significant. The study demonstrated that fingernail clippings are a suitable alternative specimen type to hair to monitor for marijuana use and abuse.

Determination of 8 Diuretics and Probenecid in Human Urine by Gas Chromatography-Mass Spectrometry: Confirmation Procedure

A fast and sensitive method for determination of 8 diuretics (acetazolamide, bendroflumethiazide, bumetanide, chlorthalidone, furosemide, hydrochlorothiazide, metolazone, triamterene) and masking agent (probenecid) in human urine using gas-chromatography with mass spectrometric detection is described. The extraction of the substances as function of the nature of organic solvent, mixing time and pH of aqueous phase was studied. The tandem mass spectrometry was used to increase selectivity of diuretics determination due to elimination of background interferences. Fragmentation reactions were studied for each compound and their collision energies were optimized to obtain the best selectivity. The results of method’s validation demonstrate its suitability in routine analysis for confirmation purposes.

Banxia xiexin decoction prevents the development of gastric cancer

BACKGROUND In China banxia xiexin decoction(BXD)has been used in treating gastric cancer(GC)for thousands of years and BXD has a good role in reversing GC histopathology,but its chemical composition and action mechanism are still unknown.AIM To investigate the mechanism of action of BXD against GC based on transcriptomics,network pharmacology,in vivo and in vitro experiments.METHODS The transplanted tumor model was prepared,and the nude mouse were pathologically examined after administration,and hematoxylin-eosin staining was performed.The active ingredients of BXD were quality controlled and identified using ultra-performance liquid chromatography tandem quadrupole electrostatic field orbitrap mass spectrometry(UPLC-Q-Orbitrap MS/MS),and traditional Chinese medicines systems pharmacology platform,drug bank and the Swiss target prediction platform to predict the relevant targets,the differentially expressed genes(DEGs)of GC were screened by RNA-seq sequencing,and the overlapping targets were analyzed to obtain the key targets and pathways.Cell Counting Kit-8,apoptosis assay,cell migration and Realtime fluorescence quantitative polymerase chain reaction were used for in vitro experiments.RESULTS All dosing groups inhibited the growth of transplanted tumors in laboratory-bred strain nude,with the capecitabine group and the BXD medium-dose group being the best.A total of 29 compounds and 859 potential targets in BXD were identified by UPLC-Q-Orbitrap MS/MS and network pharmacology,RNA-seq sequencing found 4767 GC DEGs,which were combined with network pharmacology and analyzed 246 potential therapeutic targets were obtained and pathway results showed that BXD may against GC through the Phosphoinositide 3-kinase(PI3K)/protein kinase B(AKt)signaling pathway.In vitro cellular experiments confirmed that BXDcontaining serum and LY294002 could inhibit the proliferation of GC cells,promote apoptosis,and inhibit the migration of GC cells by decreasing the expression of EGFR,PIK3CA,IL6,BCL2 and AKT1 in the PI3K-Akt pathway in MGC-803 expression.CONCLUSION BXD has the effect of inhibiting tumor growth rate and delaying the development of GC.Its mechanism of action may be related to the regulation of PI3K-Akt signaling pathway.

Research on accurate quantitation technique using liquid chromatography coupled with triple quadrupole mass spectrometry and experiment optimization—take a novel diuretic as an example

Liquid chromatography coupled with the triple quadrupole mass spectrometry(LC-QQQ MS)technique is the most commonly used technique for quantitative analysis.It is widely used in pharmacology,targeted metabolomics,Chinese medicine quality control,and other research fields.The technique monitors only characteristic precursors and product ions through multiple reaction monitoring(MRM)mode and can detect targeted molecules in complex matrix with high specificity and sensitivity.In the present study,a diarylamide derivative diuretic was used as an example to introduce the method establishment and parameter optimization of this liquid chromatography-mass spectrometry technique.Diuretic and its internal standard could be completely separated within a 5-min gradient,and the quantitative linear range was 1–1000 ng/mL with R2=0.9996 in practical samples.This study showed that the key to the method development for LC-QQQ MS was the selection of the LC mobile phase,the elution gradient,the declustering potential,and the collision energy of compounds in MS.

基于UPLC-Triple-TOF MS/MS对巴氏杀菌乳中磷脂成分的分析

基于超高效液相色谱-串联四极杆飞行时间高分辨质谱(ultra-high performance liquid chromatographytriple quadrupole-time of flight tandem mass spectrometry,UPLC-Triple-TOF MS/MS)法对巴氏杀菌乳中的磷脂成分进行分析鉴定。采用色谱柱ACQUITY UPLC^®BEH C18(2.1 mm×100 mm,1.7μm),以流动相A水-甲醇-乙腈(1∶1∶1,V/V)和流动相B异丙醇-乙腈(1∶1,V/V)进行梯度洗脱,在电喷雾电离正模式下采集数据。依据高分辨质谱提供的保留时间、准分子离子、二级碎片等脂质分析数据,并结合标准品碎裂方式等信息,共鉴定出磷脂分子68种。其中,磷脂酰胆碱22种,占比7.98%;磷脂酰乙醇胺17种,占比56.60%;磷脂酰丝氨酸10种,占比1.70%;磷脂酰肌醇7种,占比1.33%;鞘磷脂12种,占比32.39%。本研究采用灵敏度高、精密度及稳定性良好的UPLC-Triple-TOF MS/MS方法实现了对牛乳中磷脂的全面定性与定量分析。此方法检测出的牛乳磷脂信息完整、磷脂种类多于其他检测技术,可为牛乳的磷脂研究提供数据基础。

GLOBAL ANALYSIS OF THE METABOLITES OF CURCUMIN IN RATS BY ULTRA PERFORMANCE LIQUID CHROMATOGRAPHY COUPLED WITH QUADRUPOLE TIME OF-FLIGHT TANDEM MASS SPECTROMETRY

Curcumin,a safe natural yellow pigment with a wide range of pharmacological activities,is used both in herbal drugs and as a food coloring agents.Studies have shown that curcumin would suffer from extensive metabolism in vivoand the predominant metabolic pathways are reduction and conjugation.In order to comprehensively study the metabolism and enrich the metabolic profile of cxurcumin in vivo,we carried out this research.A systematic method with highly sensitive UPLC-Q/TOF-MS was established to analyze different biological samples of rats after

气相色谱-三重四极杆质谱法测定黄芪中42种农药残留

目的建立气相色谱-三重四极杆质谱法测定黄芪中42种农药的方法。方法黄芪中的多组分农药采用乙腈提取,上清液经N-丙基乙二胺、十八烷基硅烷键合硅胶、硅胶净化,采用程序升温进样口上机测定,基质匹配曲线外标法定量。结果42种农药在0.01~1.00μg/mL范围内线性关系良好,相关系数为0.9954~0.9999,在空白基质中添加低(0.02 mg/kg)、中(0.40 mg/kg)、高(2.00 mg/kg)3个不同浓度的混合标准品各6份,加标回收率为72.5%~109.3%,相对标准偏差为1.25%~6.07%,检出限为0.002~0.010mg/kg,定量限为0.005~0.030 mg/kg。在100批次黄芪样本中检出6种农药,分别是α-硫丹、对硫磷、甲基对硫磷、硫环磷、氯氰菊酯、氰戊菊酯,样品检出率6.0%,样品超标率1.0%,超标农药为氯氰菊酯。结论本方法灵敏度高、准确性好,适用于黄芪中42种农药的同时测定。

改进和优化黑果枸杞及其制品中花青素测定的pH示差法

建立一种基于美国官方分析化学师协会(Association of Official Analytical Chemists,AOAC)方法检测黑果枸杞及其制品中花青素含量的改进pH示差法。考察了黑果枸杞及其制品中花青素的最佳提取和检测条件,通过液相色谱-三重四级杆串联质谱法鉴别出黑果枸杞中花青素的具体化学结构,并计算出混合花青素的平均摩尔质量。通过分光光度法测得混合花青素的平均摩尔消光系数,对改进后的pH示差法进行方法学验证和花青素的含量测定。结果显示,最佳提取和检测条件如下:黑果枸杞花青素提取溶剂为盐酸-80%(体积分数)乙醇(3∶97,体积比),料液比为1∶100(g∶mL),提取温度为50℃,提取时间为30 min,缓冲溶液稀释5倍后静置平衡20 min。液相色谱-三重四级杆串联质谱法鉴别黑果枸杞中主要以矮牵牛素类花青素为主(占97.96%),黑果枸杞特有的混合花青素平均摩尔质量为912.7 g/mol,平均摩尔消光系数为29591 L/(mol·cm)。pH示差法改进后能够满足方法学验证要求,固体样品和液体样品最低检出限分别为28.2 mg/100 g、0.282 mg/100 mL。方法改进后花青素提取增长率均大于20%,静置平衡20 min后单次检测结果精密度小于0.3%。以矮牵牛素类花青素代替矢车菊素-3-O-葡萄糖苷计算花青素含量平均提高了2.41倍,能真实地反映黑果枸杞及其制品中花青素的含量。

高效液相色谱-三重四级杆质谱测定黄花蒿中青蒿素含量方法的设计

利用高效液相色谱-三重四级杆质谱仪建立了黄花蒿中青蒿素含量的测定方法,并进行线性与范围、精密度、回收率及实验室比对方法学验证。结果表明:青蒿素在3~300 ng/mL线性良好(R^(2)=0.9994),检出限和定量限分别为0.25和0.75μg/g;该方法精密度良好,重复性RSD在2.0%~4.8%;平均加样回收率在93.8%~109.8%。分别在3个实验室对青蒿素含量比对检测,各实验室检测分析同一样品相对标准偏差在0.5%~3.3%。该实验项目难度适中,在保证可操作的同时具一定的创新性,可培养学生的科研探索精神,适用于研究生的中药成分分析开放性实验教学。

复合露酒的非挥发性成分鉴定及抗疲劳效应

该研究采用高效液相色谱-四级杆飞行时间串联质谱联用(HPLC-Q-TOF-MS/MS)法对复合露酒(38%vol)中的非挥发性化合物进行检测,并将复合露酒灌胃至小鼠22 d,考察其对小鼠负重游泳的影响,评价其抗疲劳的保健作用。结果表明,从复合露酒(0.2257 g生药/mL)中共鉴定出52种非挥发性物质,包括皂苷类24种、黄酮类6种、核苷类4种、氨基酸类4种、生物碱类3种、其他11种。与模型组相比,低、中、高剂量组小鼠体质量减少量均极显著减少(P<0.01);中、高剂量组小鼠负重游泳时间均极显著延长(P<0.01);低、中剂量组小鼠血尿素氮(BUN)含量显著增加(P<0.01,P<0.05);低、中、高剂量组小鼠乳酸脱氢酶(LDH)活力、肝糖原(LG)含量显著增加(P<0.01,P<0.05),说明该款复合露酒非挥发性成分丰富,可增强身体对负荷的适应性,具有明显的抗疲劳效果,对功能性食品开发提供一定的基础。

高效液相色谱-串联四极杆质谱法测定荔枝中降糖氨酸A和亚甲基环丙基甘氨酸

建立高效液相色谱-串联四极杆质谱定量分析荔枝中降糖氨酸A和亚甲基环丙基甘氨酸两种降糖氨酸的测定方法。荔枝样品以90%乙醇为提取溶剂进行超声提取,离心取上清,氮吹后用水复溶。经丹磺酰氯衍生化后,采用Waters HSS T3色谱柱(100 mm×2.1 mm,1.8μm)进行分离,柱温为35℃,水(含0.1%甲酸)和乙腈为流动相,梯度洗脱,流量为0.3 mL/min。质谱采用电喷雾电离源,正离子扫描,多反应监测模式进行检测。两种降糖氨酸的质量浓度在0.01~0.50μg/mL范围内与其色谱峰面积线性良好,相关系数均大于0.999,降糖氨酸A的检出限为0.05 mg/kg,亚甲基环丙基甘氨酸的检出限为0.08 mg/kg,加标回收率为81.4%~98.7%,相对标准偏差为3.2%~5.9%(n=6)。该方法操作简单,分析时间短,灵敏度高,准确可靠,为荔枝中降糖氨酸A和亚甲基环丙基甘氨酸两种降糖氨酸的测定提供了有效的技术手段。

超高效液相色谱-三重四极杆质谱法同时测定纺织品中30种芳香胺类化合物的含量

取0.1 g 5 mm×5 mm的纺织品小片,加入17 mL(70±2)℃柠檬酸盐缓冲溶液(pH 6.0),参考GB/T 17592—2011进行还原裂解、萃取、浓缩,加适量甲醇稀释,采用超高效液相色谱-三重四极杆质谱法同时测定30种芳香胺类化合物的含量。以ZORBAX Eclipse Plus C18色谱柱作固定相,不同体积比0.1%(体积分数)甲酸溶液和甲醇的混合溶液作流动相进行梯度洗脱,电喷雾离子源正离子(ESI+)模式电离,外标法定量。结果显示:各目标物的质量浓度在50~2000μg·L^(-1)内和峰面积呈线性关系,检出限(3S/N)为0.05~1.69μg·kg^(-1);按照标准加入法进行回收试验,测定值的相对标准偏差(n=6)为3.0%~7.0%,回收率为60.3%~96.5%。方法用于两个质控样品的分析,测定值和指定值基本一致。

超高效液相色谱-三重四级杆串联质谱法测定化妆品中达克罗宁和新康唑

利用超高效液相色谱-三重四级杆串联质谱技术,建立化妆品中达克罗宁和新康唑非法添加物定性定量检测方法。样品经饱和氯化钠溶液分散,乙腈提取,超声波冰浴30 min助提。采用C18柱色谱柱(100 mm×2.1 mm,1.9μm),用流动相A(0.1%甲酸水)和流动相B(甲醇)进行梯度洗脱,流量为0.3 mL/min,柱温为30℃,进样体积为2μL。达克罗宁和新康唑的质量浓度在1~100 ng/mL范围内与色谱峰面积线性关系良好,相关系数均大于0.999。当取样质量为0.2 g时,质量分数定量限均为0.1μg/g,检出限均为0.03μg/g。该方法灵敏、快速,可用于化妆品中达克罗宁和新康唑两种目标物的测定。

高效液相色谱-串联四极杆质谱法测定人参组培不定根中11种皂苷成分

建立高效液相色谱-串联四极杆质谱(HPLC-MS/MS)法定量分析人参组培不定根中11种皂苷成分。样品经粉碎研磨,以70%甲醇水溶液为溶剂进行超声提取,离心过滤后测定。采用C_(18)色谱柱(100 mm×2.1 mm,1.8μm),用水和乙腈进行梯度洗脱,流量为0.3 mL/min,柱温为35℃。质谱采用电喷雾电离源,负离子扫描,多反应监测模式进行检测。11种皂苷的质量浓度在0.1~10μg/mL(Rb1为0.2~10μg/mL)范围内和响应强度线性相关,相关系数均大于0.995,各皂苷的定量限为0.001~0.010 g/kg,加标回收率为90.43%~97.82%,相对标准偏差为1.93%~6.33%(n=6)。该方法操作简单,分析时间短,灵敏度高,准确可靠,适用于人参组培不定根中多种皂苷类成分的同时测定。

自动QuEChERS结合UPLC-MS/MS测定莲雾中苯并咪唑类农药残留

为了建立自动QuEChERS结合高效液相色谱-串联质谱法测定莲雾中多菌灵、噻菌灵、苯菌灵及甲基硫菌灵4种苯并咪唑类农药残留量的检测方法。将莲雾样品采用混合试剂(5.5 g硫酸镁+1.5 g氯化钠+1.0 g柠檬酸钠+0.5 g柠檬酸二钠)进行净化,经QuEChERS自动样品制备系统进行制备后,应用超高效液相色谱-三重四级杆串联质谱法进行分析。结果表明,4种农药在1.00~10.00 ng/mL质量浓度范围内线性关系良好,决定系数(R2)均大于0.99;0.1、1.0、5.0 mg/kg 3个添加水平下,在莲雾基质中添加回收率为84%~105%,相对标准偏差为0.8%~9.5%(n=3),方法检出限和定量限分别为0.1~0.5μg/kg和0.5~10.0μg/kg。综上,该方法简便省时,净化效果好,灵敏度及准确度高,可用于同时测定莲雾中多菌灵、噻菌灵、苯菌灵及甲基硫菌灵4种苯并咪唑类农药的残留量。

液相色谱-三重四极杆复合线性离子阱质谱法测定烟用香精香料中9种有机酸的含量

采用液相色谱-三重四极杆复合线性离子阱质谱法定性定量检测烟用香精香料中苹果酸、柠檬酸、乳酸、丙二酸、琥珀酸、马来酸、酒石酸、己二酸、乙酰丙酸等9种有机酸。取0.1 g烟用香精香料样品,加入20 mL水,超声提取10 min。取上清液1 mL,过0.22μm水相滤膜后用水稀释10倍,按照优化的仪器工作条件测定。在Synergi Hydro-RP色谱柱上用不同体积比的0.1%(体积分数,下同)甲酸溶液和含0.1%甲酸的甲醇溶液的混合液梯度洗脱分离各有机酸后,用电喷雾离子源负离子模式电离,多反应监测-信息依赖采集-增强子离子(MRM-IDA-EPI)模式扫描,MRM模式定量,保留时间结合EPI标准品二级质谱库定性。结果表明:9种有机酸的质量浓度均在一定范围内和定量子离子峰面积呈线性关系,检出限(3s/k)为0.003~0.018 mg·L^(-1);对实际样品进行加标回收试验,回收率为73.3%~112%,日内(n=6)、日间(n=5)精密度试验所得测定值的相对标准偏差分别不大于10%和不大于15%;方法用于142种烟用香精香料样品的分析,检出率较高的4种有机酸为乳酸、苹果酸、琥珀酸和柠檬酸。

配合饲料中64种药物超高效液相色谱-三重四极杆串联质谱检测方法的研究

[目的]建立同时检测配合饲料中64种药物的超高效液相色谱-三重四极杆串联质谱(ultra-high performance liquid chromatography-triple quadrupole tandem mass spectrometry,UHPLC-MS/MS)法,提高非法添加物的检测效率。[方法]采用Waters HSS T3型色谱柱(2.1 mm×100 mm,1.8μm)进行分离,流动相A为0.1%甲酸水溶液,流动相B为含0.1%甲酸的乙腈溶液,梯度洗脱,流速为0.40 mL/min,进样量为2μL;采用电喷雾离子源正离子扫描模式进行检测,多反应监测模式进行信号采集。比较4种样品提取溶剂以及2种固相萃取柱处理对目标药物的回收率,确定样品前处理的最佳方法。利用建立的UHPLC-MS/MS法对宁夏回族自治区不同来源的100批次配合饲料样品进行64种药物检测。[结果]配合饲料样品均质后,用含0.2%甲酸的乙腈水溶液(乙腈∶水=8∶2,V/V)提取,利用Oasis PRiME HLB型固相萃取柱对样品净化,多数目标药物的回收率在60%以上。64种药物在浓度为5.0~200.0μg/L的范围内线性关系良好,相关系数(R)均大于0.99;不同药物的定量限在5.0~10.0μg/kg;阳性添加5.0、20.0、50.0μg/kg 3个浓度的平均回收率在41.00%~120.49%,批内相对标准偏差(RSD)在0.54%~15.94%,批间RSD在1.25%~13.64%。在100个批次的配合饲料样品中均未检出目标药物。[结论]建立的UHPLC-MS/MS法线性关系良好、回收率高、精密度好,具有较高的重现性和较好的可操作性,可用于配合饲料中非法添加64种药物的筛查。

失笑散化学成分分析

目的分析失笑散的化学成分。方法采用超高效液相色谱串联三重四极杆飞行时间质谱(UPLC-Q-TOF-MS)法,色谱柱为Cortecs UPLC T3柱(100 mm×2.1 mm,1.6μm),流动相为0.1%甲酸水溶液-乙腈(梯度洗脱),流速为0.3 mL/min,柱温为30℃,进样量为2μL;电喷雾离子源(ESI),正负离子模式。结果共解析出53个化学成分,其中组方药材蒲黄中23个,五灵脂中14个,其余16个为两者共有。蒲黄独有成分及其与五灵脂共有成分均以黄酮类成分为主,而五灵脂独有成分以萜类成分为主。结论该方法操作简便,重复性好,可为进一步研究失笑散的效应-物质基础提供依据。

高效液相色谱-四级杆-飞行时间质谱法测定荔枝果实中29种农药多残留

采用高效液相色谱-四极杆-飞行时间质谱技术结合优化的QuEChERS方法,建立了荔枝全果中29种农药的多残留检测分析方法。样品经乙腈提取,利用无水硫酸镁吸水和氯化钠盐析作用,进行离心分层后,取部分乙腈上清液进行净化,净化剂为无水MgSO_(4)、N-丙基乙二胺吸附剂、石墨化碳黑吸附剂,采用电喷雾离子源正负离子交换扫描方式对29种农药数据信息进行采集。29种农药在质量浓度0.001~0.2 mg/L内具有较好线性相关性(相关系数R^(2)均大于0.99),在3个添加水平(0.01、0.1、0.5 mg/kg)下,29种农药的回收率均值为70.2%~102.4%,相对标准偏差为2.4%~6.2%。方法检出限为0.1~3μg/kg,定量限为0.3~10μg/kg。该方法具有操作便捷、回收率高和灵敏度高等特点,可用于同时快速测定荔枝中29种农药的多残留。