Simultaneous determination of nalbuphine and its prodrug sebacoly dinalbuphine ester in human plasma by ultra‐performance liquid chromatography–tandem mass spectrometry and its application to pharmacokinetic study in humans

A rapid, simple, sensitive and selective ultraperformance liquid chromatography–tandem spectrometry (UPLC‐MS/MS) method for the determination of nalbuphine and its prodrug sebacoly dinalbuphine ester (SDE) was developed and validated in human plasma. The sample pretreatment involves basification and iterative liquid–liquid extraction with ethyl‐ether–dichloromethane (7:3, v/v) solution, followed by LC separation and positive electrospray ionization (ESI) API‐3000 mass spectrometry detection. The chromatography was on a Waters Acquity UPLC BEH HILIC column (2.1 × 100 mm, 1.7 µm). The mobile phase was composed of acetonitrile and water (83:17, v/v) that contained 0.2% formic acid and 4 mm ammonium formate at a flow rate of 0.25 mL/min. Ethylmorphine and naloxine were selected as the SDE and nalbuphine internal standard (IS), respectively. The calibration curve for both was linear over the range from 0.05 to 20 ng/mL, with correlation coefficients ≥0.995. The lower limit of quantification was set at 0.05 ng/mL. The intra‐ and inter‐day precision values for nalbuphine and SDE were acceptable as per FDA guidelines. The method was applied successfully to determine nalbuphine concentration in human plasma samples obtained from four Taiwanese volunteers receiving intramuscularly administration of sebacoyl dinalbuphine ester. The method is sensitive, selective and directly applicable to human pharmacokinetic studies involving nalbuphine. Copyright © 2013 John Wiley & Sons, Ltd.     

A simple,fast, and sensitive method for the measurement of serum nicotine,cotinine, and nornicotine by LC–MS/MS

The measurement of nicotine and its metabolites has been used to monitor tobacco use. A high‐sensitivity method (<1 ng/mL) is necessary for the measurement in serum or plasma to differentiate nonsmokers from passive smokers. Here, we report a novel LC–MS/MS method to quantify nicotine, cotinine, and nornicotine in serum with high sensitivity. Sample preparation involved only protein precipitation, followed by online turbulent flow extraction and analysis on a porous graphitic carbon column in alkaline conditions. The chromatography time was 4 min. No significant matrix effects or interference were observed. The lower limit of quantification was 0.36, 0.32, and 0.38 ng/mL for nicotine, cotinine, and nornicotine, respectively, while accuracy was 91.6–117.1%. No carryover was observed up to a concentration of 48 , 550, and 48 ng/mL for nicotine, cotinine, and nornicotine, respectively. Total CV was <6.5%. The measurement of nicotine and cotinine was compared with an independent LC–MS/MS method and concordant results were obtained. In conclusion, this new method was simple, fast, sensitive, and accurate. It was validated to measure nicotine, cotinine, and nornicotine in serum for monitoring tobacco use.     

Quantification of 1-(13) C-L-methionine in rat serum with hydrophilic interaction liquid chromatography coupled with tandem mass spectrometry and its application in pharmacokinetic study

A rapid, selective and sensitive hydrophilic interaction liquid chromatography (HILIC) coupled with tandem mass spectrometry (MS/MS) method was developed to determine 1‐¹³C‐l ‐methionine in rat serum. Proteins in serum were precipitated using acetonitrile and the supernatant was separated after centrifugation. 1‐¹³C‐l ‐phenylalnine was used as the internal standard. HILIC–tandem mass spectrometry analysis was performed on a hydrophilic interaction silica column (TSK‐GEL AMIDE‐80) using a linear gradient elution system, acetonitrile−5 mm ammonium acetate containing 0.1% formic acid and multiple reaction monitoring mode for 1‐¹³C‐l ‐methionine and 1‐¹³C‐l ‐phenylalnine. The assay was validated with a linear range between 10 and 150 ng mL⁻¹ (r ≥ 0.99) and a lower limit of quantification of 10 ng mL⁻¹, calculated with weighted (1/x²) least squares linear regression. The RSD of intra‐day precision was smaller than 3.6% and the inter‐day RSD less than 6.5%, while the average recovery was 100.48% with an RSD of accuracy within 2.9%, determined from quality control samples. The HILIC‐MS/MS method was fully validated and successfully applied to the in vivo pharmacokinetic study of stable‐isotope 1‐¹³C‐l ‐methionine in rats. Copyright © 2011 John Wiley & Sons, Ltd.     

Simultaneous determination of sibutramine and its active metabolites in human plasma by LC‐MS/MS and its application to a pharmacokinetic study

A simple and sensitive liquid chromatography–electrospray ionization–tandem mass spectrometry (LC‐ESI‐MS/MS) technique was developed and validated for the determination of sibutramine and its N‐desmethyl metabolites (M1 and M2) in human plasma. After extraction with methyl t‐butyl ether, chromatographic separation of analytes in human plasma was performed using a reverse‐phase Luna C₁₈ column with a mobile phase of acetonitrile–10 mm ammonium formate buffer (50:50, v/v) and quantified by ESI‐MS/MS detection in positive ion mode. The flow rate of the mobile phase was 200 μL/min and the retention times of sibutramine, M1, M2 and internal standard (chlorpheniramine) were 1.5, 1.4, 1.3 and 0.9 min, respectively. The calibration curves were linear over the range 0.05–20 ng/mL, for sibutramine, M1 and M2. The lower limit of quantification was 0.05 ng/mL using 500 μL of human plasma. The mean accuracy and the precision in the intra‐ and inter‐day validation for sibutramine, M1 and M2 were acceptable. This LC‐MS/MS method showed improved sensitivity and a short run time for the quantification of sibutramine and its two active metabolites in plasma. The validated method was successfully applied to a pharmacokinetic study in human. Copyright © 2011 John Wiley & Sons, Ltd.     

Simultaneous determination of plasma nicotine and cotinine by UHPLC–MS/MS in C57BL/6 mice and its application in a pharmacokinetic study

Plasma concentrations of nicotine and its active metabolite cotinine are highly correlated with its biological effects. A UHPLC–MS/MS method was developed, validated and applied for nicotine and cotinine analysis in mice plasma. Chromatographic separation was achieved on a BEH HILIC column using acetonitrile (0.1% formic acid) and 10 mm ammonium formate as mobile phase. The gradient elution was performed at 0.4 mL/min with a run time of 3.6 min. The quantitative ion transition was m/z 163.1 > 130.0 for nicotine, m/z 177.1 > 80.0 for cotinine and m/z 167.1 > 134.0 for nicotine‐D₄ (internal standard, IS). For both nicotine and cotinine, the calibration range was 5–500 ng/mL with 5 ng/mL as the lower limit of quantitation, and the intra‐ and inter‐day bias and imprecision were ?4.61–12.00% and <11.12%. The IS normalized recovery was 90.62–98.95% for nicotine and 89.18–101.53% for cotinine, and the IS normalized matrix factor was 106.00–116.44% for nicotine and 100.34–109.85% for cotinine. Both nicotine and cotinine were stable under conventional storage conditions. The validated method has been applied to a pharmacokinetic study in mice to calculate the pharmacokinetic parameters for both analytes.     

Simultaneous LC–MS/MS analysis of eicosanoids and related metabolites in human serum,sputum and BALF

The differences among individual eicosanoids in eliciting different physiological and pathological responses are largely unknown because of the lack of valid and simple analytical methods for the quantification of individual eicosanoids and their metabolites in serum, sputum and bronchial alveolar lavage fluid (BALF). Therefore, a simple and sensitive LC–MS/MS method for the simultaneous quantification of 34 eicosanoids in human serum, sputum and BALF was developed and validated. This method is valid and sensitive with a limit of quantification ranging from 0.2 to 3 ng/mL for the various analytes, and has a large dynamic range (500 ng/mL) and a short run time (25 min). The intra‐ and inter‐day accuracy and precision values met the acceptance criteria according to US Food and Drug Administration guidelines. Using this method, detailed eicosanoid profiles were quantified in serum, sputum and BALF from a pilot human study. In summary, a reliable and simple LC–MS/MS method to quantify major eicosanoids and their metabolites was developed and applied to quantify eicosanoids in human various fluids, demonstrating its suitability to assess eicosanoid biomarkers in human clinical trials.     

Simultaneous determination of the novel thiosemicarbazone anti‐cancer agent,Bp4eT,and its main phase I metabolites in plasma: Application to a pilot pharmacokinetic study in rats

Novel thiosemicarbazone metal chelators are extensively studied anti‐cancer agents with marked and selective activity against a wide variety of cancer cells, as well as human tumor xenografts in mice. This study describes the first validated LC‐MS/MS method for the simultaneous quantification of 2‐benzoylpyridine 4‐ethyl‐3‐thiosemicarbazone (Bp4eT) and its main metabolites (E/Z isomers of the semicarbazone structure, M1‐E and M1‐Z, and the amidrazone metabolite, M2) in plasma. Separation was achieved using a C₁₈ column with ammonium formate/acetonitrile mixture as the mobile phase. Plasma samples were treated using solid‐phase extraction on 96‐well plates. This method was validated over the concentration range of 0.18–2.80 μM for Bp4eT, 0.02–0.37 μM for both M1‐E and M1‐Z, and 0.10–1.60 μM for M2. This methodology was applied to the analysis of samples from in vivo experiments, allowing for the concentration–time profile to be simultaneously assessed for the parent drug and its metabolites. The current study addresses the lack of knowledge regarding the quantitative analysis of thiosemicarbazone anti‐cancer drugs and their metabolites in plasma and provides the first pharmacokinetic data on a lead compound of this class. Copyright © 2013 John Wiley & Sons, Ltd.     

HILIC-MS/MS method development for targeted quantitation of metabolites: practical considerations from a clinical diagnostic perspective

The development of targeted assays for polar molecules is a persistent challenge in quantitative metabolite measurement. In addressing these challenges, hydrophilic interaction liquid chromatography (HILIC) has proved to be a valuable, though under-used and poorly understood chromatographic technique. This work has addressed a number of components that are intrinsic in development of a high-throughput, specific and sensitive assay for metabolites using HILIC-MS/MS. Generally accepted HILIC doctrine, such as addition of water to all mobile phases and re-equilibration time, was shown to be flawed under gradient HILIC mode. The effect of non-classical mobile phase additives on HILIC-MS/MS specificity, sensitivity and assay throughput was shown for endogenous metabolites. A broad evaluation of columns and mobile phases for the retention of varied molecular classes was performed, elucidating the empirical nature of HILIC method development. Application of the empirical evaluations performed in the paper was demonstrated by detailing a method development cycle for methylmalonic acid to achieve a highly selective and sensitive HILIC-MS/MS quantitation capable of high-throughput analysis for clinical utility.     

Simultaneous quantification and semi‐quantification of amentoflavone and its metabolites in human intestinal bacteria by liquid chromatography Orbitrap high‐resolution mass spectrometry

A quick, easy, effective method followed by ultra‐high‐pressure liquid chromatography coupled with linear ion trap–Orbitrap tandem mass spectrometry (UHPLC‐LTQ‐Orbitrap MS) was developed for the simultaneous identification and quantification of the metabolites produced by amentoflavone (AMF) in human intestinal bacteria from human feces. The method validated for quantification of AMF concerning precision, accuracy, recovery, matrix effect, stability and limits showed acceptable results. Compared with blank human intestinal bacteria chromatography, three metabolites were identified based on high‐accuracy protonated precursors and multi‐stage mass spectrometry (MSⁿ ) using the proposed strategy. At the same time, a new method was developed for semi‐quantification of three metabolites. We describe the trend over 24 h of concentration–time curves for AMF and its metabolites. Moreover, the main metabolic pathway of AMF was clarified in human intestinal bacteria. The method was validated and successfully applied to the detection and quantification of AMF and its metabolites.     

Bioanalysis of acetylcarnitine in cerebrospinal fluid by HILIC–mass spectrometry

Acetyl‐l ‐carnitine (ALCAR) is a potential biomarker for the modulation of brain neurotransmitter activity, but is also present in cerebrospinal fluid (CSF). Recent studies have utilized hydrophilic interaction liquid chromatography–tandem mass spectrometry (HILIC‐MS/MS) based assays to detect and quantify ALCAR within biofluids such as urine, plasma and serum, using various sample pretreatment procedures. In order to address the need to quantify ALCAR in CSF on a high‐throughput scale, a new and simple HILIC‐MS/MS assay has been successfully developed and validated. For rapid analysis, CSF sample pretreatment was performed via ‘dilute and shoot’ directly onto an advanced HILIC column prior to MS/MS detection. This newly developed HILIC‐MS/MS assay shows good recoveries of ALCAR without the need for chemical derivatization and multistep sample extraction procedures. The employment of this assay is suitable for the high‐throughput bioanalysis and quantification of ALCAR within the CSF of various animal models and human clinical studies. Copyright © 2015 John Wiley & Sons, Ltd.     

Determination of trimethylamine‐N‐oxide in combination with l‐carnitine and γ‐butyrobetaine in human plasma by UPLC/MS/MS

An ultra‐high‐performance liquid chromatography–mass spectrometry (UPLC/MS/MS) method was developed and validated for the quantification of trimethylamine‐N‐oxide (TMAO) simultaneously with TMAO‐related molecules l ‐carnitine and γ‐butyrobetaine (GBB) in human blood plasma. The separation of analytes was achieved using a Hydrophilic interaction liquid chromatography (HILIC)‐type column with ammonium acetate–acetonitrile as the mobile phase. TMAO determination was validated according to valid US Food and Drug Administration guidelines. The developed method was successfully applied to plasma samples from healthy volunteers. Copyright © 2015 John Wiley & Sons, Ltd.     

Quantitative determination of trigonelline in mouse serum by means of hydrophilic interaction liquid chromatography–MS/MS analysis: Application to a pharmacokinetic study

Trigonelline is a pyridine alkaloid found in fenugreek seeds and coffee beans. Most of the previous studies are concerned with the quantification of trigonelline along with other constituents in coffee herbs or beverages. Only a few have focused on its determination in animal or human tissues by applying different modes of HPLC with UV or MS detection. The aim of the study was to develop and validate a fast and simple method for trigonelline determination in serum by the use of hydrophilic interaction liquid chromatography (HILIC) with ESI‐MS/MS detection. Separation of trigonelline was achieved on a Kinetex HILIC column operated at 35°C with acetonitrile–ammonium formate (10 mm , pH = 3) buffer mixture (55:45, v/v) as the mobile phase. The developed method was successfully applied to determine trigonelline concentration in mouse serum after intravenous administration of 10 mg/kg. The developed assay is sensitive (limit of detection = 1.5 ng/mL, limit of quantification = 5.0 ng/mL) and linear in a concentration range from 5.0 to 250.0 ng/mL. Sample preparation is limited to deproteinization, centrifugation and filtration. The application of the HILIC mode of chromatography with MS detection and selection of deuterated trigonelline as internal standard allowed a rapid and precise method of trigonelline quantification to be to developed.     

Simultaneous quantification of atorvastatin and active metabolites in human plasma by liquid chromatography-tandem mass spectrometry using rosuvastatin as internal standard

A simple, sensitive, selective and rapid liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed and validated for the quantification of atorvastatin and its active metabolites ortho-hydroxyatorvastatin and para-hydroxyatorvastatin in human plasma using rosuvastatin as internal standard (IS). Following simple liquid-liquid extraction, the analytes were separated using an isocratic mobile phase on a reversed-phase C18 column and analyzed by MS in the multiple reaction monitoring mode using the respective [M+H]+ ions, m/z 559/440 for atorvastatin, m/z 575/466 for ortho-hydroxyatorvastatin, m/z 575/440 for para-hydroxyatorvastatin and m/z 482/258 for the IS. The assay exhibited a linear dynamic range of 0.1-20 ng/mL for atorvastatin and its two metabolites in human plasma. The lower limit of quantification was 100 pg/mL with a relative standard deviation of less than 8%. Acceptable precision and accuracy were obtained for concentrations over the standard curve range. The average absolute recoveries of atorvastatin, ortho-hydroxyatorvastatin, para-hydroxyatorvastatin and the IS from spiked plasma samples were 54.2 +/- 3.2, 50.1 +/- 3.8, 65.2 +/- 3.6 and 71.7 +/- 2.7%, respectively. A run time of 2.5 min for each sample made it possible to analyze more than 300 human plasma samples per day. The validated method has been successfully used to analyze human plasma samples for application in pharmacokinetic, bioavailability or bioequivalence studies.     

Development of a high‐performance liquid chromatography method with fluorescence detection for the routine quantification of tamoxifen,endoxifen and 4‐hydroxytamoxifen in plasma from breast cancer patients

To date, several methods for the quantification of tamoxifen and its metabolites have been developed, most of which employ liquid chromatography tandem–mass spectrometry (LC–MS/MS). These methods are highly sensitive and reproducible, but are also time‐consuming and require expensive equipment; one of their main disadvantages is matrix ionization effects. A more viable option, particularly in developing countries, is high‐performance liquid chromatography coupled with UV or fluorescence detection. We developed and validated a method for simultaneous quantification of tamoxifen, endoxifen and 4‐hydroxytamoxifen based on high‐performance liquid chromatography with fluorescence detection in a reverse‐phase column. The method is rapid (16 min plus 5 min of column re‐equilibrium), accurate (80–100%) and precise (0.23–6.00%), and does not require any additional irradiation process. Sample pretreatment consists of protein precipitation with acetonitrile under alkaline conditions, employing only 200 μL plasma. The validated method's wide range allowed quantification of steady‐state levels in patients under standard tamoxifen treatment (20 mg/day). This assay is ready for application in clinical studies and routine quantification of tamoxifen, endoxifen and 4‐hydroxytamoxifen in healthcare institutions.     

Detection and validated quantification of toxic alkaloids in human blood plasma--comparison of LC-APCI-MS with LC-ESI-MS/MS

Poisonings with toxic plants may occur after abuse, intentional or accidental ingestion of plants. For diagnosis of such poisonings, multianalyte procedures were developed for detection and validated quantification of the toxic alkaloids aconitine, atropine, colchicine, coniine, cytisine, nicotine and its metabolite cotinine, physostigmine, and scopolamine in plasma using LC-APCI-MS and LC-ESI-MS/MS. After mixed-mode solid-phase extraction of 1 ml of plasma, the analytes were separated using a C8 base select separation column and gradient elution (acetonitrile/ammonium formate, pH 3.5). Calibration curves were used for quantification with cotinine-d(3), benzoylecgonine-d(3), and trimipramine-d(3) as internal standards. The method was validated according to international guidelines. Both assays were selective for the tested compounds. No instability was observed after repeated freezing and thawing or in processed samples. The assays were linear for coniine, cytisine, nicotine and its metabolite cotinine, from 50 to 1000 ng/ml using LC-APCI-MS and 1 to 1000 ng/ml using LC-ESI-MS/MS, respectively, and for aconitine, atropine, colchicine, physostigmine, and scopolamine from 5 to 100 ng/ml for LC-APCI-MS and 0.1 to 100 ng/ml for LC-ESI-MS/MS, respectively. Accuracy ranged from -38.6 to 14.0%, repeatability from 2.5 to 13.5%, and intermediate precision from 4.8 to 13.5% using LC-APCI-MS and from -38.3 to 8.3% for accuracy, from 3.5 to 13.8%, for repeatability, and from 4.3 to 14.7% for intermediate precision using LC-ESI-MS/MS. The lower limit of quantification was fixed at the lowest calibrator in the linearity experiments. With the exception of the greater sensitivity and higher identification power, LC-ESI-MS/MS had no major advantages over LC-APCI-MS. Both presented assays were applicable for sensitive detection of all studied analytes and for accurate and precise quantification, with the exception of the rather volatile nicotine. The applicability of the assays was demonstrated by analysis of plasma samples from suspected poisoning cases.     

Validated liquid chromatography–tandem mass spectrometry method for quantification of ticagrelor and its active metabolite in human plasma

A rapid, simple and sensitive LC–MS/MS method was established and validated for simultaneous quantification of ticagrelor and its active metabolite AR‐C124910XX in human plasma. After plasma samples were deproteinized with acetonitrile, the post‐treatment samples were chromatographed on a Dikma C₁₈ column interfaced with a triple quadrupole tandem mass spectrometer. Electrospray negative ionization mode and multiple reaction monitoring were adopted to assay ticagrelor and AR‐C124910XX. Acetonitrile and 5 mΜ ammonium acetate was used as the mobile phase with a gradient elution at a flow rate of 0.5 mL/min. The method was linear in the range of 0.781–800 ng/mL for both ticagrelor and AR‐C124910XX with a correlation coefficient ≥0.994. The intra‐ and inter‐day precisions were within 12.61% in terms of relative standard deviation and the accuracy was within ±7.88% in terms of relative error. The LC–MS/MS method was fully validated for its sensitivity, selectivity, stability, matrix effect and recovery. This convenient and specific LC–MS/MS method was successfully applied to the pharmacokinetic study of ticagrelor and AR‐C124910XX in healthy volunteers after an oral dose of 90 mg ticagrelor.     

Quantification of docetaxel and its main metabolites in human plasma by liquid chromatography/tandem mass spectrometry

Docetaxel is an antineoplastic agent widely used in therapeutics. The objective of this study was to develop and validate a routine assay, using liquid chromatography coupled to tandem mass spectrometry (LC/MS/MS), for the simultaneous quantification of docetaxel and its main hydroxylated metabolites in human plasma. A structural analogue, paclitaxel, was used as the internal standard. Determination of docetaxel and four metabolites (M1, M2, M3 and M4) was achieved using only 100 microL of plasma. Liquid-liquid extraction was used for sample preparation, with extraction efficiency of at least 90% for all analytes. Detection used positive-mode electrospray ionization in selected reaction monitoring mode. The lower limit of quantification (LLOQ) was 0.5 ng/mL for all analytes. The assay was linear in the calibration curve range 0.5-1000 ng/mL and acceptable precision and accuracy (<15%) were obtained with concentrations above the LLOQ. This method was sufficiently selective and sensitive for quantification of metabolites in plasma from cancer patients receiving docetaxel chemotherapy, and is suitable for routine analyses during pharmacokinetic studies.     

An improved LC‐MS/MS method for simultaneous determination of 1,5‐dicaffeoylquinic acid and its active metabolites in human plasma and its application to a pharmacokinetic study in patients

In this study, a sensitive, selective and reproducible liquid chromatography–tandem mass spectrometry method for the simultaneous determination of 1,5‐dicaffeoylquinic acid (1,5‐DCQA) and its active metabolites, 1‐caffeoyl‐5‐feruoylquinic acid and 1,5‐O‐diferuoylquinic acid, in human plasma, using puerarin as internal standard, was developed and validated. Analytes were extracted from plasma samples by liquid–liquid extraction with ethyl acetate, separated on a C₁₈ reversed‐phase column with water containing 5 mM ammonium acetate and acetonitrile as the mobile phase and detected by electrospray ionization mass spectrometry in negative selected reaction monitoring mode. The accuracy and precision of the method were acceptable and linearity was good over the range 1–200 ng/mL for each analyte. In addition, the selectivity, extraction recovery and matrix effect were satisfactory too. The validated LC‐MS/MS method was successfully applied to phase II clinical pharmacokinetic study of 1,5‐DCQA in patients. Copyright © 2010 John Wiley & Sons, Ltd.     

亲水作用色谱-串联质谱测定尿液中尼古丁和可替宁

建立了测定人尿液中尼古丁和可替宁含量的亲水作用色谱-串联质谱(HILIC-MS/MS)方法。尿样加入尼古丁-d4和可替宁-d3同位素内标后,用水稀释10倍,经过滤后的滤液由超高效液相色谱-串联质谱(UPLC-MS/MS)进行分离分析。采用ACQUITY UPLC~BEH HILIC色谱柱(50 mm×3.0 mm,1.7μm),以甲醇和体积分数为0.1%的氨水为流动相,流速为0.2 mL/min,在电喷雾电离源正离子模式下测定尿液中尼古丁和可替宁的含量,用标准曲线法定量。尼古丁和可替宁在1.0~1 000μg/L范围内线性关系良好,相关系数分别为0.994 9和0.995 8;检出限分别为0.082μg/L和0.077μg/L;定量限分别为0.27μg/L和0.26μg/L;加标回收率分别为90.4%~103.5%和93.0%~104.6%;相对标准偏差分别为4.80%~6.21%和4.22%~7.15%。应用所建立的方法测定了200份尿样,结果表明,吸烟人群尿中尼古丁含量为26.68~854.30μg/L,可替宁含量为36.66~1 191.18μg/L(n=86,M_(nicotine)=76.00μg/L,M_(nicotine)=83.52μg/L,M为中位数);非吸烟人群尿中尼古丁含量为5.08~69.66μg/L,可替宁含量为3.16~28.21μg/L(n=114,Mnicotine=7.53μg/L,M_(nicotine)=3.79μg/L)。该方法快速灵敏,操作简单,适用于尿样中尼古丁和可替宁的批量测定,能满足烟草暴露评价的需要。     

Development and validation of an LC‐MS/MS method for simultaneous quantitative analysis of free and conjugated bisphenol A in human urine

Bisphenol A (BPA) is an environmental endocrine‐disrupting chemicals that is widely used in common consumer products. There is an increasing concern regarding human exposure to BPA owing to the potential adverse effects associated with its estrogenic activity. For assessing environmental exposure to BPA, it is essential to have a sensitive, accurate and selective analytical method, especially one that can detect low BPA levels in complex sample matrices. In this study, we developed and validated an accurate, sensitive, and robust liquid chromatography–tandem mass spectrometry method for simultaneous quantification of free BPA and BPA β‐d ‐glucuronide (BPA‐gluc) concentrations in human urine with only a single injection. Calibration curves were linear over a concentration range of 1–100 ng/mL for BPA and 10–1000 ng/mL for BPA‐gluc. The levels of the analytes were determined quantitatively with HPLC/ESI‐MS/MS by using negative electrospray ionization in the select ion monitoring mode and a pentaflouraphenyl propyl column. The validated method was applied to the analysis of spot urine specimens collected from randomly selected healthy human subjects. Copyright © 2013 John Wiley & Sons, Ltd.