Rapid Quantification of Astilbin in Rat Plasma by Liquid Chromatography-tandem Mass Spectrometry and Its Application to Pharmacokinetic Study

Astilbin is a potential immunosuppressive agent with minor cytotoxicity. Its oral bioavailability is supposed to be rather low and therefore a sensitive analytical method is required for its pharmacokinetic study after oral administration. A simple, sensitive and rapid liquid chromatography-tandem mass spectrometry（LC-MS/MS） method was developed and validated for the determination of astilbin in rat plasma. Plasma samples were subjected to liquid-liquid extraction with ethyl acetate and separated by reversed phase high performance liquid chromatography（HPLC） with methanol-0.01%（volume fraction） formic acid（50：50, volume ratio） as mobile phase. Quantitive determination was achieved on negative LC-MS/MS by a multiple reaction moitoring method with transitions m/z 449.1→150.9（quantifier） and m/z 449.1→284.9（qualifier） for astilbin and m/z 128.9→42.0 for internal standard（IS）. A lower limit of quantification（LLOQ） of ng/mL was achieved within a short cycle time of 3.4 min. The method was successfully applied to a pharmacokinetic study involving oral and intravenous administrations of 6 mg/kg astilbin to six rats.     

Rapid and Sensitive Liquid Chromatography-Tandem Mass Spectrometry for Quantification of Glycyrrhetic Acid in Human Plasma

A simple, rapid and sensitive liquid chromatography-tandem mass spectrometry(LC-MS/MS) for the determination of glycyrrhetic acid in human plasma with ginsenoside Rh2 as internal standard was developed and validated. The plasma samples were prepared via liquid-liquid extraction with ethyl acetate. Chromatographic separation was accomplished on a Venusil MP-C18(50 mm×2.1 mm, 5 μm i.d.) column at 25 °C. The mobile phase consisted of acetonitrile/5 mmol?L-1 ammonium acetate(10:90, volume ratio) at a flow rate ...     

Development and Validation of a Sensitive LC-MS/MS Method for the Simultaneous Analysis of Three-Tropane Alkaloids in Blood and Urine

A simple and sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed for the simultaneous analysis of three tropane alkaloids in blood and urine. After 1 mL of a blood or urine sample was extracted using a liquid–liquid extraction method with ethyl acetate at pH 8 and homatropine as the internal standard, the tropane alkaloids were separated. An Allure PFP propyl column (50 mm × 2.1 mm, 5 µm) separated the tropane alkaloids using an acetonitrile-buffer solution (20 mmol/L ammonium acetate and 0.1% formic acid, pH 4) (70:30) as the mobile phase at a flow-rate of 0.2 mL/min in isocratic mode, with the LC-MS/MS in the positive ionization mode. For each compound, detection was related to two daughter ions (scopolamine: m/z 304.4 → 138.1 and 155.9; atropine: m/z 290.3 → 124.0 and 93.1; anisodamine: m/z 306.3 → 140.1 and 91.1; and homatropine: m/z 276.3 → 124.3 and 142.1). The tropane alkaloids exhibited excellent linearity in the range of 0.05–100 ng/mL in blood and 0.2–100 ng/mL in urine, with a limit of detection range from 0.02 to 0.05 ng/mL for biological materials. The extraction recoveries of atropine, scopolamine, and anisodamine were more than 53% in the blood and urine; the interday and intraday RSDs were less than 10%; the within-day and between-day accuracy were between ?9.8% and +8.8%. The present method is simple and rapid, as shown by its application to a clinical case. This method is useful for routine analysis of tropane alkaloids in cases of suspected tropane alkaloid poisoning.     

Rapid Determination of Ranitidine in Human Plasma by Liquid Chromatography-Tandem Mass Spectrometry and Its Application to a Clinical Pharmacokinetic Study

A rapid and sensitive assay based on high performance liquid chromatography-tandem mass spectrometry(LC-MS/MS) was developed for the determination of ranitidine(RAN) in human plasma with codeine as internal standard(IS).After protein precipitation with acetonitrile,the analyte and IS were separated on a Zorbax SB-Aq C18 column(150 mm×4.6 mm i.d.,5 μm) eluted with a mobile phase consisting of methanol/acetonitrile/10 mmol/L ammonium acetate containing 1% formic acid(pH=2.4)(volume ratio 12.5:12.5:75) at a flow rate of 1.0 mL/min.Detection was performed by electrospray ionization in the positive ion mode followed by the multiple reaction monito-ring(MRM) of the transitions of RAN at m/z 315.1→176.3 and of IS at m/z 300.1→165.1.The method was linear over a concentration range of 1―1000 ng/mL(r=0.9991) with a lower limit of quantitation(LLOQ) of 1 ng/mL and a limit of detection(LOD) of 0.3 ng/mL.Accuracy as relative error was from-0.01% to-1.7% and intra-day and inter-day precisions as relative standard deviation were ≤8.9% and ≤5.5%,respectively.The method was successfully applied to a pharmacokinetic study of ranitidine,getting a single oral dose(160 mg) to healthy volunteers.     

Rapid and Sensitive LC-MS/MS Method for Quantification of Fexofenadine in Human Plasma——Application to a Bioequivalence Study in Chinese Volunteers

A rapid and sensitive liquid chromatography-tandem mass spectrometry method（LC-MS/MS）was developed and validated for the quantification of fexofenadine in human plasma,to conduct comparative bioavailability studies.Human plasma was extracted with a mixture of dichloromethane-diethyl ether（volume ratio 2∶3）in a basic environment and the extract was separated on a C18 column with a mobile phase consisting of acetonitrile-methanol-10 mmol/L ammonium acetate（volume ratio 45∶45∶10）.The analytes were detected via electrospray ionization（ESI）tandem mass spectrometry in the multiple-reaction-monitoring（MRM）mode.The linearity was within a range of 1-1000 ng/mL.The intra-and inter-day precision were〈4.1% and〈4.8%,respectively,and the accuracy was in the range of 95.0%-105%.The method was applied to the quantification of fexofenadine human plasma from 20 healthy male Chinese volunteers,according to a single dose,randomized,two-way crossover design with a two-week washout period.The mean values of major pharmacokinetic parameters of ρmax,AUC0-48,AUC0-∞,tmax,and t1/2 were determined from the plasma concentration.The analysis of variance（ANOVA）did not show any significant difference between the two products of fexofenadine and 90% confidence intervals fell within the acceptable range for bioequivalence.     

液相色谱-串联质谱法测定液态乳制品中的苯代三聚氰胺

建立了液态乳制品中苯代三聚氰胺的高效液相色谱-串联质谱(HPLC-MS/MS)测定方法。优化了前处理条件、液相色谱和质谱参数。样品经LC-C18固相萃取柱富集净化后,采用ZORBAX-Eclipse Plus C18色谱柱分离,流动相为乙腈-水(15∶85,体积比),流速为0.3 mL/min。采用正离子模式的电喷雾质谱检测,多反应(MRM)选择离子监测,定量离子与定性离子分别为m/z 104.1与m/z 146.0,外标法定量。结果表明,苯代三聚氰胺在2~100 μg/L范围内线性关系良好,相关系数为0.999 1,方法的检出限和定量下限分别为1.0 μg/kg和3.0 μg/kg。在低、中、高3个加标水平下的平均回收率为77%~105%,相对标准偏差(RSD)为2.3%~5.0%。该方法操作简单、准确可靠,适用于液态乳制品中苯代三聚氰胺的测定。     

Determination of Chlorzoxazone in Rat Plasma by LC-ESI-MS/MS and Its Application to a Pharmacokinetic Study

A sensitive LC-ESI-MS/MS method for determination of chlorzoxazone in rat plasma has been developed. Chromatographic separation was achieved on a Zorbax SB-C₁₈ column, with 45:55 (v/v) acetonitrile–water as the mobile phase. A LC-ESI-MS/MS was performed in a multiple reactions monitoring (MRM) mode using target ions m/z 167.5→131.6 for chlorzoxazone and m/z 230.7→185.6 for phenobarbital (internal standard). The calibration plots were linear over the range of 10.0–2,000 ng/mL. Intra-day and inter-day precisions were better than 5.1% and 6.8%, respectively. The validated method was successfully used to analyze the drug in samples of rat plasma for pharmacokinetic study.     

液相色谱-串联质谱法测定人血浆中的头孢替安浓度

为评价盐酸头孢替安酯片在健康人体内的药代动力学特征,应用蛋白沉淀-液相色谱-串联质谱技术建立了灵敏度高、特异性强、快速的健康受试者血浆中头孢替安的分析方法。选用 Waters Symmtry C18色谱柱(50 mm×4.6 mm,5μm),以甲醇和1 mmol/ L 乙酸铵水溶液梯度洗脱,流速1.0 mL/ min。在多反应监测模式(MRM)下,采用电喷雾离子化源,正离子扫描模式下进行定量分析。标准曲线在5.0~5000 ng/ mL 范围内线性关系良好(r>0.99),定量下限为5.0 ng/ mL,方法学验证部分结果均符合生物样本定量测定的要求。本方法快速、灵敏、重现性好,并成功应用于健康受试者盐酸头孢替安酯片药动学研究,同时也为同类药物在人体生物基质中的定量检测提供参考。     

Measurement of Free and Glucuronidated Cardamonin in Rat Plasma and Bile Using UPLC-MS/MS and Its Application to a Pharmacokinetic and Bile Excretion Study

A rapid and accurate ultra-high-performance liquid chromatography-electrospray ionization-tandem mass spectrometry(UPLC-MS/MS) method was established and validated for the measurement of two forms of cardamonin, i.e., free and glucuronidated, in the plasma and bile of rats. Cardamonin and an internal standard (1,8-dihydroxyanthraquinone) were extracted from plasma and bile with ethyl ether via liquid-liquid extraction. The analytes in the extracts were separated by an Agilent Zorbax Stable Bond-C₁₈ column(2.1 mm×50 mm, 1.8 μm) under isocratic elution conditions[acetonitrile(A) and 0.1% ammonium formate in water(B), 40:60(volume ratio)] with a flow rate of 0.4 mL/min, and mass spectrometry in negative ion MRM mode was implemented for analysis. Good linearity over the wide ranges of 0.01-5 μg/mL for plasma and 0.025-10 μg/mL for bile samples was acquired. Method validation was performed according to the FDA guidelines for bioanalytical methods.     

液相色谱-串联质谱法测定动物性食品中20种抗生素类药物残留

建立了一种专属、灵敏的方法用于同时检测动物性食品中β-内酰胺类青霉素类抗生素、大环内酯类抗生素、四环族抗生素和林可胺类共20 种抗生素药物残留.首先对动物性食品中的抗生素类药物进行提取,再经HLB固相萃取柱净化,采用电喷雾离子源,以正离子检测方式进行质谱分析.实验结果表明,在10-200 μg/L质量浓度范围内上述20...     

A Simple LC-MS/MS Method for the Quantification of PDA-66 in Human Plasma

The treatment of cancer is one of the most important pharmacotherapeutic challenges. To this end, chemotherapy has for some time been complemented by targeted therapies against specific structures. PDA-66, a structural analogue of the inhibitor of serine–threonine kinase glycogen synthase kinase 3β SB216763, has shown preclinical antitumour effects in various cell lines, with the key pathways of its anticancer activity being cell cycle modulation, DNA replication and p53 signalling. For the monitoring of anticancer drug treatment in the context of therapeutic drug monitoring, the determination of plasma concentrations is essential, for which an LC-MS/MS method is particularly suitable. In the present study, a sensitive LC-MS/MS method for the quantification of the potential anticancer drug PDA-66 in human plasma with a lower limit of quantification of 2.5 nM is presented. The method was successfully validated and tested for the determination of PDA-66 in mouse plasma and sera.     

高效液相色谱-串联质谱法测定地表水样品中5种有机磷酸酯代谢物

将固相萃取(SPE)和高效液相色谱-串联质谱(LC-MS/MS)结合,建立了河水样品中5种有机磷酸酯(OPEs)代谢物的分析方法。样品过滤后,使用HLB固相萃取小柱进行富集净化,采用6 m L甲醇洗脱后氮吹定容。以Luna Phenyl-Hexyl色谱柱为分离柱,甲醇和50 mmol·L-1乙酸铵水溶液为流动相梯度洗脱,在电喷雾负离子模式下,采用多反应监测模式(MRM)进行测定。优化条件下,仪器测定限(IDL)为0.002~1.15μg·L~(-1),方法检出限(MDL)为0.15~4.48 ng·L~(-1),实际水样加标浓度为10 ng·L~(-1)和50 ng·L~(-1)时回收率分别为54.1%~83.6%和57.8%~102%,相对标准偏差(RSD)分别为5.3%~19.5%和2.8%~15.7%。考察了基质效应对5种化合物分析的影响,同时应用该方法对武汉7个湖水样品进行分析,除DEHP外其它4种OPEs代谢物均有检出。该方法具有良好的精密度和准确度,可用于有机磷酸酯代谢物的环境行为研究。     

LC-MS/MS方法快速检测血浆中小檗碱的浓度

小檗碱在生物体内以极低的浓度发挥着良好的疗效,准确测定其血药浓度对其药理学性质的研究具有重要意义。本文建立了高效液相色谱-质谱联用快速测定血浆中小檗碱浓度的方法,采用Waters XTerraTM MSC18色谱柱(2.1×50mm,3.5μm),柱温25℃,以0.2%醋酸水溶液-乙腈为流动相梯度洗脱,流速为0.2mL/min,以苯妥英为内标。质谱采用电喷雾电离源,以选择反应监测模式进行定量分析,血浆样品用乙腈直接沉淀处理。结果表明,小檗碱在0.01～0.5μg/mL浓度范围线性关系良好,最低检测浓度为5ng/mL(S/N=3)。日内、日间RSD均小于15%(n=5)。本文建立的方法操作简单、灵敏度高、分析时间短,适用于小檗碱血药浓度监测及药代动力学研究。     

A new liquid chromatography-tandem mass spectrometry method for determination of parabens in human placental tissue samples

Endocrine disruptors are a group of organic compounds widely used, which are ubiquitous in the environment and in biological samples. The main effect of these compounds is associated with their ability to mimic or block the action of natural hormones in living organisms, including humans. Parabens (esters of p-hydroxybenzoic acid) belong to this group of compounds. In this work, we propose a new liquid chromatography-tandem mass spectrometry (LC-MS/MS) method to asses the presence of parabens most commonly used in industrial applications (methyl-, ethyl-, propyl- and butyl-paraben) in samples of human placental tissue. The method involves the extraction of the analytes from the samples using ethyl acetate, followed by a clean-up step using centrifugation prior to their quantification by LC-MS/MS using an atmospheric pressure chemical ionization (APCI) interface in the negative mode. Deuterated bisphenol A (BPA-d₁₆) was used as surrogate. Found detection limits (LOD) ranged from 0.03 to 0.06 ng g⁻¹ and quantification limits (LOQ) from 0.1 to 0.2 ng g⁻¹, while inter- and intra-day variability was under 13.8%. The method was validated using standard addition calibration and a spike recovery assay. Recovery rates for spiked samples ranged from 82% to 108%. This method was satisfactorily applied for the determination of parabens in 50 placental tissue samples collected from women who live in the province of Granada (Spain).     

Rapid Determination of Montelukast in Human Plasma by LC-ESI-MS/MS and Its Application to a Bioequivalence Study

Abstract

A rapid liquid chromatography–electrospray ionization–tandem mass spectrometry (LC-ESI-MS/MS) method was developed for the determination of montelukast in human plasma. The extraction of montelukast from plasma (300 µL) involved protein precipitation. Quantitation was performed using LC-ESI-MS/MS, operating in the positive ion and selective reaction monitoring (SRM) mode. The total chromatographic run time for the analysis was 1.5 min. A linear dynamic range was established from 5 to 800 ng mL^?1 for montelukast. The method was fully validated especially with regard to real subject sample analysis. It was successfully applied to a bioequivalence study in 18 healthy human subjects under fed condition (human subjects were allowed to eat as per the prescribed diet for bioequivalence study).     

LC-MS/MS法快速高效检测尿液中尼古丁及其9种代谢物

以氘代尼古丁、氘代可的宁、3-OH-氘代可的宁、氘代尼古丁葡萄糖醛酸复合物、氘代可的宁葡萄糖醛酸复合物、3-OH-氘代可的宁葡萄糖醛酸复合物作内标, 在LC-MS/MS的大气压化学电离(APCI)离子化模式下, 建立了快速检测吸烟者尿液中尼古丁及其9种代谢物的方法, 并对19个实际样品进行了测试和判别分析(DA). 实验前处理简单, 色谱运行时间仅为3.8 min. 结果表明, 尼古丁及其代谢物的精密度在0.5%～5.5%之间, 回收率在94%～109%之间, 线性相关系数均大于0.995. DA分析充分区别开了不同量的吸烟者, 进一步的相关性分析表明吸烟者24 h尿液中的尼古丁及其9种代谢物含量与卷烟抽吸量的分析因子之间均有较强正相关性.     

On-line solid phase extraction LC-MS/MS analysis of pharmaceutical indicators in water: A green alternative to conventional methods

A method using automated on-line solid phase extraction (SPE) directly coupled to liquid chromatography/tandem mass spectrometry (LC-MS/MS) has been developed for the analysis of six pharmaceuticals by isotope dilution. These selected pharmaceuticals were chosen as representative indicator compounds and were used to evaluate the performance of the on-line SPE method in four distinct water matrices. Method reporting limits (MRLs) ranged from 10 to 25 ng/L, based on a 1 mL extraction volume. Matrix spike recoveries ranged from 88 to 118% for all matrices investigated, including finished drinking water, surface water, wastewater effluent and septic tank influent. Precision tests were performed at 50 and 1000 ng/L with relative standard deviations (RSDs) between 1.3 and 5.7%. A variety of samples were also extracted using a traditional off-line automated SPE method for comparison. Results for both extraction methods were in good agreement; however, on-line SPE used approximately 98% less solvent and less time. On-line SPE coupled to LC-MS/MS analysis for selected indicators offers an alternative, more environmentally friendly, method for pharmaceutical analysis in water by saving time and costs while reducing hazardous waste and potential environmental pollution as compared with off-line SPE methods.     

Determination of benzophenones in human placental tissue samples by liquid chromatography-tandem mass spectrometry

Benzophenones (BPs) are a family of compounds widely used to protect the skin and hair from UV irradiation. Despite human exposure to BPs through dermal application of products containing sunscreen agents and the increasing evidence that BPs are able to interfere with endocrine systems, few studies have examined the occurrence of BPs in humans. In this work, we propose a new liquid chromatography-tandem mass spectrometry (LC-MS/MS) method to determine six BPs, namely, benzophenone-1 (BP-1), benzophenone-2 (BP-2), benzophenone-3 (BP-3), benzophenone-6 (BP-6), benzophenone-8 (BP-8) and 4-hydroxybenzophenone (4-OH-BP) in human placental tissue samples. The method involves an extraction step of the analytes from the samples using ethyl acetate, followed by a clean-up step using centrifugation prior to their quantification by LC-MS/MS using an atmospheric pressure chemical ionization (APCI) interface in the positive mode. Benzophenone-d₁₀ (BP-d₁₀) was used as surrogate. Found detection limits (LOD) ranged from 0.07 to 0.3 ng g⁻¹ and quantification limits (LOQ) from 0.3 to 1.0 ng g⁻¹, while inter- and intra-day variability was under 5%. The method was validated using standard addition calibration and a recovery assay. Recovery rates for spiked samples ranged from 98 to 104%. This method was satisfactorily applied for the determination of BPs in 16 placental tissue samples collected from women who live in Granada (Spain).     

水稻和土壤中呋虫胺残留的固相萃取/液相色谱-串联质谱分析方法

建立了呋虫胺在水稻(糙米、稻壳和稻草3种基质)和土壤中残留的液相色谱-电喷雾串联质谱(LC-ESI MS/MS)检测方法。各基质经乙腈提取,PSA柱净化后,以Agilent ZORBAX SB-C18色谱柱分离,电喷雾电离串联质谱正离子多重反应监测(MRM)模式进行测定。在不同加标水平下,对呋虫胺在4种不同基质中的回收率和相对标准偏差(RSD)进行测定。结果表明,呋虫胺在糙米中的回收率为73.8%~97.2%,RSD为3.1%~9.9%;在稻壳中的回收率为77.6%~80.3%,RSD为2.5%~5.8%;在稻草中的回收率为76.0%~94.0%,RSD为4.8%~8.8%;在土壤中的回收率为83.6%~93.3%,RSD为4.6%~6.4%。该方法具有样品前处理简单、快速、分析时间短的特点,灵敏度、准确度和精密度均符合农药残留检测要求。