Determination of loratadine and its active metabolite in human plasma by high-performance liquid chromatography with mass spectrometry detection

A new sensitive and selective liquid chromatography coupled with mass spectrometry (LC/MS/MS) method for quantification of loratadine (LOR) and its active metabolite descarboethoxyloratadine (DSL) in human plasma was validated. After addition of the internal standard, metoclopramide, the human plasma samples (0.3 ml) were precipitated using acetonitrile (0.75 ml) and the centrifuged supernatants were partially evaporated under nitrogen at 37 degrees C at approximately 0.3 ml volume. The LOR, DSL and internal standard were separated on a reversed phase column (Zorbax SB-C18, 100 mmx3.0 mm i.d., 3.5 microm) under isocratic conditions using a mobile phase of an 8:92(v/v) mixture of acetonitrile and 0.4% (v/v) formic acid in water. The flow rate was 1 ml/min and the column temperature 45 degrees C. The detection of LOR, DSL and internal standard was in MRM mode using an ion trap mass spectrometer with electrospray positive ionisation. The ion transitions were monitored as follows: 383-->337 for LOR, 311-->(259+294+282) for DSL and 300-->226.8 for internal standard. Calibration curves were generated over the range of 0.52-52.3 ng/ml for both LOR and DSL with values for coefficient of determination greater than 0.994 by using a weighted (1/y) quadratic regression. The lower limits of quantification were established at 0.52 ng/ml LOR and DSL, respectively, with an accuracy and precision less than 20%. Both analytes demonstrated good short-term, long-term, post-preparative and freeze-thaw stability. Besides its simplicity, the sample treatment allows obtaining a very good recovery of both analytes, around 100%. The validated LC/MS/MS method has been applied to a pharmacokinetic study of loratadine tablets on healthy volunteers.     

HPLC-MS/ESI+测定人血浆中喹硫平及其代谢产物

目的建立同时测定人血浆中喹硫平及其磺氧化-、7-羟基-和7-羟基-氮-去烷基-代谢产物浓度的高效液相色谱-电喷雾电离质谱联用法.方法采用Kromasil C18 反相柱(250 mm×4.6 mm,5 μm),以水(含甲酸1.70 mmol·L-1, 醋酸铵5.8 mmol·L-1)-乙腈(6535)为流动相,流速0.95 mL·min-1. 质谱采用电喷雾电离源正离子模式(ESI+),选择离子监测(SIR)各物质准分子离子峰,样品用固相萃取法处理.结果喹硫平和磺氧化喹硫平在10～2 000 μg·L-1,7-羟基-喹硫平和7-羟基-氮-去烷基喹硫平在1～200 μg·L-1线性关系良好,萃取回收率均＞85%,方法回收率均＞95%,日内、日间RSD均＜15%.结论该方法专一性强、灵敏度高、简单,可用于研究喹硫平的代谢机制以及药物动力学.     

Determination of clarithromycin in human plasma by liquid chromatography-electrospray ionization tandem mass spectrometry

A rapid and sensitive method has been developed for the determination of clarithromycin in human plasma with liquid chromatography-tandem mass spectrometry. Clarithromycin and the internal standard, telmisartan were precipitated from the matrix (50 microl) with 200 microl acetonitrile and separated by HPLC using formic acid:10 mM ammonium acetate:methanol (1:99:400, v/v/v) as the mobile phase. The assay based on detection by electrospray positive ionization mass spectrometry in the multiple-reaction monitoring mode was finished within 2.4 min. Linearity was over the concentration range 10-5000 ng/ml with a limit of detection of 0.50 ng/ml. Intra- and inter-day precision measured as relative standard deviation were <3.73% and <9.93%, respectively. The method was applied in a bioequivalence study of two tablet formulations of clarithromycin.     

Simultaneous determination of aceclofenac and its three metabolites in plasma using liquid chromatography-tandem mass spectrometry

A new LC/MS/MS-based method allows simultaneous determination of aceclofenac and its three metabolites (4'-OH-aceclofenac, diclofenac, and 4'-OH-diclofenac) in plasma. After acetonitrile-induced precipitation of proteins from the plasma samples, aceclofenac, 4'-OH-aceclofenac, diclofenac, 4'-OH-diclofenac, and flufenamic acid (an internal standard) were chromatographed on a reverse-phase C(18) analytical column. The isocratic mobile phase of acetonitrile/0.1% formic acid((aq)) [80:20 (v/v)] was eluted at 0.2 mL/min. Quantification was performed on a triple-quadrupole mass spectrometer employing electrospray ionization, and the ion transitions were monitored in multiple reaction-monitoring mode. The monitored transitions for aceclofenac, diclofenac, 4'-OH-diclofenac, 4'-OH-aceclofenac and flufenamic acid were m/z 352.9-->74.9, 296.1-->251.7, 311.8-->267.7, 368.9-->74.9, and 279.9-->235.9, respectively. The coefficient of variation of the assay precision was less than 6.5%, and the accuracy ranged from 93% to 103%. The limits of detection were 2 ng/mL for aceclofenac and 0.2 ng/mL for both diclofenac and 4'-OH-diclofenac. This method was used successfully to measure the concentrations of aceclofenac and its three metabolites in plasma from healthy subjects after administration of a single 100-mg oral dose of aceclofenac. This analytic method is a very simple, sensitive, and accurate way to determine the pharmacokinetics of aceclofenac and its metabolites.     

Simultaneous determination of quetiapine and three metabolites in human plasma by high-performance liquid chromatography-electrospray ionization mass spectrometry

AIM: To develop a high performance liquid chromatography-electrospray mass spectrometry (HPLC-MS/ESI) method for simultaneous determination of quetiapine and its sulfoxide-, 7-hydroxy-, 7-hydroxy-N-dealkyl-metabo-lites in human plasma. METHODS: The HPLC separation of the compounds was performed on a Kromasil C18, (5 urn, 4.6 mm×150 mm) column, using water (formic acid: 1.70 mmol/L, ammonium acetate: 5.8 mmol/L)-acetoni trile (65:35) as mobile phase, with a flow-rate of 0.95 mL/min. The compounds were ionized in the electrospray ionization (ESI) ion source of the mass spectrometer and detected in the selected ion recording (SIR) mode. The samples were extracted using solid-phase extraction columns. RESULTS: The calibration curves were linear in the ranges of 10-2000 μg/L for quetiapine, 1-200 μg/L for its metabolites, respectively. The average extraction recoveries for all the four samples were above 85 %.     

Rapid and quantitative determination of solanesol in Nicotiana tabacum by liquid chromatography-tandem mass spectrometry

A rapid and sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) method with multiple reaction monitoring (MRM) was developed for the determination of solanesol in Nicotiana tabacum. Sample preparation was performed by ultrasonic extraction with methanol for 20 min and then supernatant was extracted with hexane. The method used atmospheric pressure chemical ionization (APCI) detection in positive-ion mode. The separation of solanesol was performed on a Symmetry Shield RP18 column with a mixture of acetonitrile and isopropanol (1:1, v/v) containing 2mM ammonium acetate as mobile phase. Quantification of solanesol was performed by the standard addition method. The limit of quantification (LOQ) and limit of detection (LOD) of solanesol were, respectively, 5.0 ng/ml (S/N=10) and 1.5 ng/ml (S/N=3). The relative standard deviations of peak area were 0.89 and 1.12% for intra-day and inter-day, respectively. The recoveries of solanesol ranged from 97.72 to 99.67% and the corresponding R.S.D.s were less than 2.7%. Analysis took 5 min, making the method suitable for rapid determination of solanesol in N. tabacum. The proposed method has been successfully applied to the analysis of solanesol in various organs of N. tabacum.     

Simultaneous determination of GFA and its active metabolites in human plasma by liquid chromatography electrospray ionization mass spectrometry and its application to pharmacokinetic studies

A sensitive and rapid liquid chromatography electrospray ionization mass spectrometry (LC-ESI-MS) method has been developed and validated for simultaneous quantification of guanfu base A (GFA) and its metabolites guanfu base I (GFI) and guanfu alcohol-amine (AA) in human plasma with phenoprolamine hydrochloride (DDPH) as the internal standard. The analytes were extracted from human plasma by using liquid-liquid extraction with ethyl acetate and the LC separation was performed on a Diamonsil C(18) analytical column (150 mm x 2.1 mm i.d., 5 microm). The MS acquisition was performed in selected ion monitoring (SIM) mode of positive ions. Analysis was carried out in SIM mode at m/z 430.25 for GFA [M+H](+), m/z 388.25 for GFI [M+H](+), m/z 346.25 for AA [M+H](+) and m/z 344.20 for the IS DDPH [M+H](+). The calibration curves were linear over the range of 50-5000 ng/mL for GFA and 5-1000 ng/mL for GFI and AA, with coefficients of correlation above 0.999. The lower limit of quantification for GFA was 1 ng/mL, while for GFI and AA were both 5 ng/mL. The intra- and inter-day precisions (CV) of analysis were within 9%, and the accuracy ranged from 91% to 108%. The overall recoveries for GFA, GFI and AA were about 94.2%, 87.8% and 80.6%, respectively. The total LC-MS run-time was only 5.5 min. This quantitation method was successfully applied to the simultaneous determination of GFA and its metabolites in human plasma for the metabolic study and pharmacokinetic evaluation.     

Determination of berberine in human plasma by liquid chromatography-electrospray ionization-mass spectrometry

A liquid chromatography-electrospray ionization-mass spectrometry (LC-ESI-MS) method for the determination of berberine in human plasma using chlorobenzylidine as the internal standard (IS) has been developed and validated. The plasma samples were prepared by LLE and the analytes were chromatographically separated on a Hanbon Lichrospher 5-C18 HPLC column under gradient elution with a mobile phase consisted of acetonitrile and 10mm ammonium acetate buffer containing 0.1% formic acid. Berberine was determined with electrospray ionisation-mass spectrometry (ESI-MS). LC-ESI-MS was performed in the selected-ion monitoring (SIM) mode using target ions at M(+)m/z 336.1 for berberine and M(+)m/z 464.1 for the IS. Calibration curve was linear over the range of 0.020-3.0 ng/ml. The lower limit of quantification (LLOQ) was 0.020 ng/ml. The intra- and inter-run variability values were less than 6.7 and 7.7%, respectively. The method has been successfully applied to determine the plasma concentration of berberine in healthy Chinese volunteers.     

Determination of zabofloxacin in rat plasma by liquid chromatography with mass spectrometry and its application to pharmacokinetic study

The objective of the present study was to develop a rapid and sensitive method for the determination of zabofloxacin, a novel, broad-spectrum fluoroquinolone antibiotic, in rat plasma. Rat plasma samples were deproteinized with methanol, and then were injected into an LC-MS system for quantification. Zabofloxacin and enrofloxacin, which served as an internal standard, were analyzed by selected ion monitoring (SIM) at m/z transitions of 402 for zabofloxacin and 360 for the internal standard. The lower limit of quantification (LLOQ) was determined to be 10 ng/mL, with acceptable linearity ranging from 10 to 5000 ng/mL (R>0.999). The validation parameters for zabofloxacin, such as absolute matrix effect (107.7-116.0%), accuracy (92.5-101.1% for intra-day and 90.3-103.8% for inter-day), precision (7.7-10.2% for intra-day and 4.2-8.9% for inter-day), and stability in rat plasma (96.0-101.8%), were found to be acceptable according to the assay validation guidelines of the FDA (2001). Following oral administration of zabofloxacin to rats at a dose of 20mg/kg, the concentration of zabofloxacin in plasma was quantifiable in plasma samples collected up to 8h following zabofloxacin administration. The method described in the present study is applicable to routine pharmacokinetic studies in rats.     

Sensitive determination of a pharmaceutical compound and its metabolites in human plasma by ultra-high performance liquid chromatography-tandem mass spectrometry with on-line solid-phase extraction

This paper describes the determination of a drug candidate and two metabolites in human plasma by column-switching LC-MS/MS after protein precipitation. Starting from a standard method with a quantitation limit of 0.5 ng/mL, a highly sensitive assay was developed, employing UHPLC separation and detection on an API 5000 mass spectrometer. The injected plasma equivalent was increased from 6 to 20 μL; conventional column trapping for compound enrichment and removal of matrix constituents was combined with high-pressure analytical separation using small particle columns to improve resolution and signal-to-noise ratio. Quantitation limits were thus lowered to between 5 and 20 pg/mL, offering the possibility to provide bioanalytical support for microdosing studies in humans. Excellent assay quality and robustness were achieved by both methods.     

Simultaneous determination of albendazole and its principal metabolites in plasma by normal phase high-performance liquid chromatography

A sensitive, specific and reproducible high-performance liquid chromatography procedure using normal phase is described for the simultaneous determination of albendazole, albendazole sulphoxide and albendazole sulphone in sheep plasma, with mebendazole as an internal standard. Analysis of plasma requires only 100 mul of sample, which is extracted with ethylacetate and injected directly onto a 5-mum normal phase column, using hexane-ethanol (445:55, v/v) as eluent, with detection at 225 nm. The standard curves in plasma were linear for both albendazole and its metabolites at concentrations from 0.1 to 10 mug/ml. The method has been applied to the determination of plasma levels of albendazole and metabolites during preliminary pharmacokinetic studies in sheep.     

Quantitative determination of spinosin in rat plasma by liquid chromatography-tandem mass spectrometry method

A sensitive method for the quantitative determination of spinosin in rat plasma was developed and validated using high-performance liquid chromatographic separation with tandem mass spectrometric detection. The analytes of interest were extracted from rat plasma samples by methyl tert-butyl ether (MTBE) after acidification with 1.0% acetic acid aqueous solution. Chromatographic separation was achieved on an Agilent Zorbax SB-C(18) (50 mm x 4.6 mm, 5 microm) using a isocratic mobile phase consisting of acetonitrile-water (30:70, v/v) with 1% isopropyl alcohol and 0.01% heptafluorobutyric acid. The flow rate was 0.2 ml/min. The column temperature was maintained at 25 degrees C. Detection was performed on a triple quadrupole tandem mass spectrometer by selected reaction monitoring (SRM) mode via electrospray ionization (ESI). The calibration curve was linear over the range of 1.00-400 ng/ml in rat plasma, with 1.00 ng/ml of the lower limit of quantification (LLOQ). The inter- and intra-day precisions and accuracy for all samples were satisfactory. The validated method was successfully applied for the pharmacokinetic study of spinosin in rat. After oral administration of 20mg/kg spinosin to rats, the main pharmacokinetic parameters of T(max), C(max), T(0.5) and AUC(0-T) were 5.33+/-0.58 h, 132.2+/-10.6 ng/ml, 4.89+/-0.37 h, 1.02+/-0.09 microg h/l, respectively.     

Simultaneous determination of ciclesonide and its active metabolite desisobutyryl-ciclesonide in human plasma by LC-APCI-MS/MS: application to pharmacokinetic study in healthy Chinese volunteers

A sensitive and highly selective liquid chromatography tandem mass spectrometric (LC/MS/MS) method was developed and validated for the determination of ciclesonide (CIC) and its active metabolite, desisobutyryl-ciclesonide (des-CIC), in human plasma. Plasma samples were extracted using methyl tert-butyl ether with mifepristone as an internal standard (IS). Separation was carried out on a C(18) column using a mixture of 0.1% formic acid solution and methanol as the mobile phase with linear gradient elution. The detection was operated with positive atmospheric pressure chemical ionization (APCI) by selective multiple reaction monitoring (SRM). The chief benefit of the present method was the high sensitivity, with the lower limit of quantification (LLOQ) as low as 10pg/mL and the linearity ranging from 10 to 10,000pg/mL for both CIC and des-CIC. The method was fully validated and successfully applied to determine CIC and des-CIC simultaneously in human plasma and proved to be suitable for phase I clinical pharmacokinetic study of inhaled ciclesonide in healthy Chinese volunteers.     

Structural elucidation of in vivo and in vitro metabolites of anisodine by liquid chromatography-tandem mass spectrometry

Liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESIMSn) was employed to investigate the in vivo and in vitro metabolism of anisodine. Feces, urine and plasma samples were collected after ingestion of 20 mg anisodine to healthy rats. Feces and urine samples were cleaned up by liquid-liquid extraction and solid-phase extraction procedures (C18 cartridges), respectively. Methanol was added to plasma samples to precipitate plasma proteins. Anisodine was incubated with homogenized liver and intestinal flora of rats in vitro, respectively, followed by extraction with ethyl acetate. LC-MSn was used for the separation and identification of the metabolites using C18 column with mobile phase of methanol/0.01% triethylamine solution (2 mM, adjusted to pH 3.5 with formic acid) (60:40, v/v). The results revealed that five metabolites (norscopine, scopine, alpha-hydroxytropic acid, noranisodine and hydroxyanisodine) and the parent drug existed in feces. Three new metabolites (dimethoxyanisodine, tetrahydroxyanisodine and trihydroxy-methoxyanisodine) were identified in urine. Four metabolites (norscopine, scopine, hydroxyanisodine and anisodine N-oxide) and the parent drug were detected in plasma. Two hydrolyzed metabolites (scopine and alpha-hydroxytropic acid) were found in rat intestinal flora incubation mixture, and two metabolites (aponoranisodine and anisodine N-oxide) were identified in homogenized liver incubation mixture.     

Simultaneous determination of alfentanil and midazolam in human plasma using liquid chromatography and tandem mass spectrometry

A fast, sensitive and selective liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the determination of alfentanil and midazolam in human plasma has been developed and validated. Alfentanil and midazolam were extracted from plasma using a mixed-mode cation exchange solid phase extraction method, with recoveries of both compounds greater than 80% at 3 different concentrations (1, 10 and 100ng/ml). Compounds were analyzed on a C(18) column with a water and methanol mobile phase gradient with acetic acid as an additive, at a flow rate of 0.3ml/min. The working assay range was linear from 0.25 to 100ng/ml for each compound. The signal to noise ratio was 80 and 40 for alfentanil and midazolam, respectively, at the lowest concentration calibration standard, with less than 10% matrix suppression by human plasma at this concentration. Alfentanil and midazolam were stable in human plasma during storage at -80°C, processing, and analysis. The procedure was validated and applied to the analysis of plasma samples from healthy human subjects administered oral and intravenous alfentanil and midazolam.     

Development and validation of a liquid chromatography-tandem mass spectrometry method for the determination of zofenopril and its active metabolite zofenoprilat in human plasma

A novel, sensitive and rapid liquid chromatographic-electrospray ionization mass spectrometric method was developed and validated for the determination of zofenopril and its active metabolite zofenoprilat in human plasma. The method was based on a single extraction step using methyl tert-butyl ether and did not require chemical derivatization. The chromatographic conditions were optimized; separation was performed on a phenyl-hexyl column (5μm, 250mm×4.6mm i.d.) with a mobile phase consisting of a solution of methanol and water (95:5, v/v) that also contained 0.1% of formic acid. A flow rate of 1.0mL/min was used. Zofenopril, zofenoprilat and the internal standard (IS) fosinopril sodium were measured using an electrospray ion source in a positive reaction monitoring mode. Linear calibration curves were generated for zofenopril concentrations between 0.1052 and 1052ng/mL and for zofenoprilat concentrations between 0.2508 and 2508ng/mL. In both cases, the coefficients of determination were greater than 0.995. The extraction recovery for zofenopril was 93.5% on average. It was 92.5% for zofenoprilat. The inter- and intra-batch precision and accuracy for both zofenopril and zofenoprilat were higher than 14%. The method was applied to measure the concentrations of zofenopril and zofenoprilat in plasma samples.     

Simultaneous determination of triptolide, wilforlide A and triptonide in human plasma by high-performance liquid chromatography-electrospray ionization mass spectrometry

A simple and sensitive method for the determination of triptolide, wilforlide A and triptonide in human plasma was developed and validated, using high-performance liquid chromatography-electrospray ionization mass spectrometry (LC-ESI-MS). Plasma samples were purified using solid-phase extraction (SPE) columns. The HPLC separation of the analytes was performed on a MACHEREY-NAGEL C(18)column (2.0 mm x 125 mm, 3 microm), using 2.7 mM formic acid containing 10 mM ammonium acetate-acetonitrile (55:45, v/v) as mobile phase, with a flow-rate of 0.25 ml/min. The compounds were ionized in the electrospray ionization (ESI) ion source of the mass spectrometer and were detected in the selected ion recording (SIR) mode. The calibration curves were linear in the 0.80-300 ng/ml range for all the three analytes, and the limits of detection were 0.25, 0.40, and 0.35 ng/ml for triptolide, wilforlide A, and triptonide, respectively. The average absolute recoveries for all the three analytes were above 81%. The methodology recoveries were greater than 91% and the relative standard deviations (RSD) of intra-day and inter-day were less than 15%. The developed method was successfully applied to the determination of triptolide, wilforlide A and triptonide concentration in patients' plasma after taking the medicament containing Tripterygium wilfordii HOOK. F.     

Quantitative determination of albendazole metabolites in sheep spermatozoa and seminal plasma by liquid chromatographic analysis with fluorescence detection

A new analytical method for the simultaneous quantitative determination of albendazole metabolites in sheep spermatozoa and seminal plasma at levels down to 46.5 ng/mL for albendazole sulphoxide (ABZ-SO), 7.5 ng/mL for albendazole sulphone (ABZ-SO₂) and 12 ng/mL for albendazole 2-aminosulphone (ABZ-SO₂NH₂) has been developed. Analytes were extracted from alkalinized samples with ethyl acetate. Separation was carried out on a C₁₈ column in the presence of tetra-n-butylammonium (TBA) hydrogen sulphate and octanesulphonate sodium (OCT), as ion-pair agents. Fluorometric detection was performed with excitation and emission wavelengths set at 290 and 320 nm, respectively. Accuracy data showed overall recoveries (±S.E.M.) of 83.1±1.2% for ABZ-SO, 98.8±0.6% for ABZ-SO₂ and 85.3±0.7% for ABZ-SO₂NH₂, in spermatozoa. Respective values in seminal plasma were 88.0±0.9%, 97.7±0.5% and 93.2±1.7%. Precision data suggested coefficient of variation (CV%) values lower than 5.9% for spermatozoa and 3.8% for seminal plasma. The method was successfully applied for the determination of the three albendazole metabolites in semen samples collected from rams that had been orally administered albendazole.     

Simultaneous determination of Aprepitant and two metabolites in human plasma by high-performance liquid chromatography with tandem mass spectrometric detection

A method for the simultaneous determination of Aprepitant, I (5-[[2(R)-[1(R)-(3,5-bistrifluoromethylphenyl)ethoxy]-3(S)-(4-fluorophenyl) morpholin-4-yl]methyl]-2,4-dihydro-[1,2,4]triazol-3-one) and two active metabolites (II and III) in human plasma has been developed. The method was based on high-performance liquid chromatography (HPLC) with atmospheric pressure chemical ionization tandem mass spectrometric (APCI-MS-MS) detection in positive ionization mode using a heated nebulizer interface. The analytes and internal standard (IV) (Fig. 1) were isolated from basified plasma using liquid–liquid extraction. The organic extracts were dried, reconstituted in mobile phase and injected into the HPLC-MS/MS system.

The analytes were chromatographed on a narrow bore (50 mm×2.0 mm, 3 μm) Keystone Scientific’s Prism R.P. analytical column, with mobile phase consisting of acetonitrile (ACN):water containing trifluoroacetic acid with pH adjusted to 3 (40:60, v/v) pumped at a flow rate of 0.5 ml/min. The MS-MS detection was performed on a Sciex API 3000 tandem mass spectrometer operated in selected reaction monitoring mode. The precursor→product ion combinations of m/z 535→277, 438→180, 452→223 and 503→259 were used to quantify I, II, III, and IV, respectively, after chromatographic separation of the analytes. The assay was validated in the concentration range of 10–5000 ng/ml for I and II and 25–5000 ng/ml for III when 1 ml of plasma was processed. The precision of the assay (expressed as coefficient of variation, CV) was less than 10% at all concentrations within the standard curve range, with adequate assay accuracy. Matrix effect experiments were performed to demonstrate the absence of any significant change in ionization of the analytes when comparing neat standards to analytes in the presence of plasma matrix. This assay was utilized to support a clinical study where multiple oral doses of I were administered to healthy subjects to investigate the pharmacokinetics, safety, and tolerability of Aprepitant. Concentrations of the two most active metabolites, which if present in high concentrations would increase the neurokinin-1 (NK₁) receptor occupancy level and therefore potentially contribute to the antiemetic action of Aprepitant, were determined.     

LC-MS／MS法测定人血浆中氯沙坦及其代谢物E-3174的浓度

目的建立LC-MS／MS法测定人血浆中氯沙坦及其代谢物E-3174血药浓度的方法。方法血浆酸化后用乙醚提取,采用同位素内标（氘3-B3174）进行测定。色谱柱：CAPCELLPACKC18Ⅲ（100mm×2．0mm,5μm）,流动相：0．02％甲酸乙腈-水溶液（53：47,v／v）;等度洗脱;流速0．3mL·min-1;进样体积5μL;电喷雾离子化,正离子MRM扫描。结果氯沙坦和E-3174线性范围均为5—500μg·L-1（r〉0．999）,最低定量限均为5μg·L-1,平均提取回收率均〉50％,批内、批间精密度RSD均〈8％。结论本方法灵敏度高、专一性好、操作简单,适用于氯沙坦的药动学研究。