An automatic 96-well solid phase extraction and liquid chromatography-tandem mass spectrometry method for the analysis of morphine, morphine-3-glucuronide and morphine-6-glucuronide in human plasma.

A bioanalytical method using automated sample transferring, automated solid phase extraction (SPE) and liquid chromatography-tandem mass spectrometry (LC-MS-MS) was developed for morphine (MOR), and its metabolites morphine-3-glucuronide (M3G) and morphine-6-glucuronide (M6G) in human plasma. Samples of 0.25 ml were transferred into 96-well plate using automatic liquid handler (Multiprobe II). Automated SPE was carried out on a 96-channel programmable liquid handling workstation (Quadra 96) using a C(18) sorbent. The extract was injected onto a silica column using an aqueous-organic mobile phase. The chromatographic run time was 3.5 min per injection, with retention times of 1.5, 2.0 and 2.6 min for MOR, M6G, and M3G, respectively. The detection was by monitoring MOR at m/z 286-->152, M6G and M3G at m/z 462-->286. The deuterated internal standards were monitored at m/z 289-->152 for MOR-d(3), and m/z 465-->289 for M6G-d(3) and M3G-d(3). The standard curve range was 0.5-50 ng ml(-1) for MOR, 1.0-100 ng ml(-1) for M6G, and 10-1000 ng ml(-1) for M3G. The inter-day precision and accuracy of the quality control samples were <8% relative standard deviation (RSD) and <7% relative error (RE) for MOR, <5% RSD and <2% RE for M6G, and <2% RSD and <4% RE for M3G.     

LC-MS/MS法测定人血浆中加巴喷丁的浓度及其药动学研究

建立液相色谱串联质谱(LC-MS/MS)法测定人血浆中加巴喷丁的浓度并将其应用于人体药动学研究。取血浆样品经甲醇沉淀蛋白后,以甲醇0.2%甲酸水溶液(80∶20)为流动相,用Inertsil ODS-3 C18柱(50 mm×2.1 mm ID,3μm)分离,采用电喷雾离子源,以多反应监测(MRM)方式进行正离子检测,定量分析的离子反应分别为m/z 172→m/z 154(加巴喷丁)和m/z 130→m/z 71(内标二甲双胍)。加巴喷丁线性范围为40.8～8.16×103 ng.mL 1,定量限为40.8 ng.mL 1,每个样品测试时间仅2.2 min,日内、日间精密度(RSD)均小于12%,准确度(RE)在±6.4%范围内。应用此法研究了20名健康志愿者单剂量口服加巴喷丁胶囊600 mg后的药动学特点。该方法快速、专属、灵敏、适用性强,可应用于加巴喷丁的人体药动学研究。     

Sensitive bioassay of bupivacaine in human plasma by liquid-chromatography-ion trap mass spectrometry

A sensitive high-performance liquid chromatography-tandem mass spectrometric (HPLC-MS-MS) method, using an ion trap spectrometer, was developed for quantitation of bupivacaine in human plasma. Bupivacaine and an internal standard (ropivacaine) were extracted in a single step from 100 microL of alkalinized plasma with diethyl-ether. The mobile phase consisted of acetonitrile with 0.1% formic acid (50:50, v/v), and was delivered at a flow rate of 0.3 mL/min. The effluent was detected by MS-MS in positive ion mode. Ionisation was performed, using an electrospray ion source, operating at 200 degrees C. The selected reaction monitoring transitions m/z 289-->m/z 140 and m/z 275-->m/z 126 were chosen for bupivacaine and ropivacaine, respectively. Calibration curves were linear over the concentration range of 3.90-500 microg/L with determination coefficients >0.996. The method is accurate (bias <10%) and reproducible (intra-assay and inter-assay precision <15%), with a quantitation limit of 3.90 microg/L, using only 100 microL of plasma. The high specificity and sensitivity, achieved by this fast method (total run-time <3 min), allowed the determination of bupivacaine plasma levels in pediatric patients, following epidural administration of bupivacaine.     

A fast and sensitive liquid chromatographic-tandem mass spectrometric method for assay of lorazepam and application to pharmacokinetic analysis

A fast and sensitive method of coupled high-performance liquid chromatography-electrospray tandem mass spectrometry for the assay of lorazepam in human plasma was developed. Plasma samples were simply treated with acetonitrile to precipitate and remove proteins and the isolated supernatants were directly injected into the HPLC/MS/MS system. Chromatographic separation was performed on a Zorbax C(18) (100 x 2.1 mm I.D.) column with a 65:35 (v/v) mixed solution of acetonitrile and 10mM aqueous formic acid being used as mobile phase. With diazepam as an internal standard, quantification was performed by selected reaction ion monitoring of the transitions of m/z 321--> m/z 275 for lorazepam and m/z 285--> m/z 193 for the internal standard. The assay was validated in the concentration range of 0.71-71.3 ng/ml in human plasma. A detection limit of 0.10 ng/ml for lorazepam was achieved, and inter- and intra-run precisions of better than 4.4% (R.S.D.) were observed. The developed method has been successfully applied for pharmacokinetic study of the drug in man.     

Simultaneous determination of clozapine and its N-desmethyl and N-oxide metabolites in plasma by liquid chromatography/electrospray tandem mass spectrometry and its application to plasma level monitoring in schizophrenic patients

A liquid chromatography tandem mass spectrometry (LC-MS-MS) assay method for the simultaneous determination of clozapine and its N-desmethyl (norclozapine) and N-oxide metabolites in human plasma is described. The compounds were extracted from plasma by a single step liquid-liquid extraction procedure and analyzed using a high performance liquid chromatography electrospray tandem mass spectrometer system. The compounds were eluted isocratically on a C-18 column, ionized using positive ion atmospheric pressure electrospray ionization method by a TurboIonspray source and analyzed using multiple reaction monitoring mode. The ion transitions monitored were m/z 327 --> m/z 270 for clozapine, m/z 313 --> m/z 192 for norclozapine, m/z 343 --> m/z 256 for clozapine-N-oxide and m/z 421--> m/z 201 for internal standard. The standard curves of clozapine, norclozapine and clozapine-N-oxide were linear over the range of 1 ng/ml to 1000 ng/ml when 0.5 ml of plasma was used for the analysis (r(2) >0.998). Three pooled plasma samples collected from patients who were treated with clozapine were used as long-term quality control samples to check the validity of spiked standard curve samples made at various times. The intra- and inter-assay variations for the spiked standard curve and quality control samples were less than 14%. These variations for the long-term patient quality control samples were less than 11%. The LC-MS-MS assay for simultaneous determination of clozapine, norclozapine and clozapine-N-oxide reported here is highly specific, sensitive, accurate and rapid. This method is currently being used for the plasma level monitoring of clozapine and its N-desmethyl and N-oxide metabolites in patients treated with clozapine. The plasma levels of clozapine, norclozapine and clozapine-N-oxide varied widely within and among patients. The data revealed that the norclozapine and clozapine N-oxide metabolites were present at about 58%+/-14% and 17%+/-6% of clozapine concentrations in plasma, respectively.     

高灵敏度LC-MS/MS法测定犬血浆中的坦洛新

犬口服盐酸坦洛新控释片后血浆药物浓度C_max小于10 ng·mL^-1，需建立测定犬血浆中坦洛新的高灵敏度液相色谱-串联质谱法(LC-MS/MS)。血浆样品加入内标苯海拉明，用正己烷-二氯甲烷(2∶1)萃取后，反相C₁₈色谱柱分离，以甲醇-乙腈-甲酸铵(30∶40∶30，v/v/v)为流动相，流速为0.4 mL·min^-1。选用大气压化学离子化源(APCI)三重四极杆串联质谱仪，以选择反应监测方式进行检测，用于定量分析的离子反应分别为m/z 409→228(坦洛新)和m/z 256→167(苯海拉明)。坦洛新线性范围为0.02～50 ng·mL^-1，定量下限为0.02 ng·mL^-1。批内、批间精密度(RSD)均小于9.72%，准确度(RE)在-2.61%～8.82%。本方法灵敏度高，专属性强，用于犬口服盐酸坦洛新控释片后的药代动力学研究。     

液相色谱-串联质谱法测定人血浆中的利培酮

利培酮为苯并异噁唑类化合物,通过阻断5-HT2受体和多巴胺D2受体发挥抗精神病作用.同其他抗精神病药物相比,利培酮所引起的椎体外系副作用更少,药效更为明显 .     

高效液相色谱-质谱/质谱联用法测定人血浆中莫沙必利

建立测定人血浆中莫沙必利的高效液相色谱-质谱/质谱联用法。取血浆样品经液-液萃取后，以乙腈为有机相，0.3%甲酸水溶液为水相，采用梯度洗脱的方式，用C₁₈柱分离，通过电喷雾离子化，以多反应监测(MRM)方式进行正离子检测。莫沙必利线性范围为0.17~68.00 ng·mL^-1，定量下限为0.17 ng·mL^-1，每个样品测试时间仅2.8 min，日内、日间精密度(RSD)均小于13%，准确度(RE)在±6.3%范围内。应用此法研究了20名志愿者单剂量口服枸橼酸莫沙必利片后的药代动力学特点。该方法、灵敏、准确、快速，适用于莫沙必利的药代动力学及生物等效性研究。     

Liquid chromatographic-tandem mass spectrometric method for the simultaneous quantitation of telmisartan and hydrochlorothiazide in human plasma

A rapid and sensitive method using liquid chromatography-tandem mass spectrometry (LC-MS/MS) has been developed for the simultaneous determination of telmisartan and hydrochlorothiazide in human plasma. Sample preparation involved liquid-liquid extraction with diethyl ether-dichloromethane (60:40, v/v). The analytes and internal standard, probenecid, were separated on a Venusil XBP-C(8) column using gradient elution with acetonitrile-10 mM ammonium acetate-formic acid at a flow rate of 1.2 mL/min. Detection was by electrospray negative ionization mass spectrometry using multiple reaction monitoring of the transitions at m/z 513.0-->469.4 for telmisartan, m/z 295.9-->268.9 for hydrochlorothiazide and m/z 283.9-->239.9 for probenecid. For both analytes, the method was linear in the range 1.00-600 ng/mL with intra- and inter-day precision (as relative standard deviation) 相似文献   

液相色谱-串联质谱法同时测定人血浆中二甲双胍和格列吡嗪

建立了快速、灵敏的液相色谱-串联质谱法测定人血浆中的二甲双胍和格列吡嗪。血浆样品经0.3%甲酸-乙腈(v/v)沉淀蛋白后，以乙腈-水-甲酸(70∶30∶0.3，v/v/v)为流动相，流速为0.50 mL·min^-1。Zorbax Extend C₁₈柱分离，采用大气压化学电离源；以选择反应监测(SRM)方式进行正离子检测。用于定量分析的离子反应分别为m/z 130→m/z 60(二甲双胍)，m/z 446→m/z 321(格列吡嗪)和m/z 256→m/z 167(内标，苯海拉明)。测定血浆中二甲双胍的线性范围为2.00～2 000 ng·mL^-1， 定量下限为2.00 ng·mL^-1； 格列吡嗪的线性范围为1.00～1 000 ng·mL^-1， 定量下限为1.00 ng·mL^-1。该方法专属性好，灵敏度高，准确快捷，适用于二甲双胍和格列吡嗪的临床药代动力学研究。     

高灵敏度LC/MS/MS法同时测定人血浆中麻黄碱和氯苯那敏

麻黄碱是存在于草麻黄和木贼麻黄等植物中的生物碱,属拟肾上腺素类药物,包括互为差向异构体的麻黄碱和伪麻黄碱两种活性不同的成分;氯苯那敏为丙胺类组胺H1-受体拮抗剂,作用较强,用量少,中枢抑制作用小,为常用抗过敏药,临床上可用于缓解各种感冒症状,与麻黄碱联合应用,用于缓解支气管哮喘与慢性喘息性支气管炎所致支气管痉挛.     

LC-MS/MS法测定人血浆中西酞普兰及其在制剂生物等效性中的应用

A sensitive and selective LC-MS/MS method for determination of citalopram in human plasma was established to study the bioequivalence of different formulations containing citalopram. The samples were simply pretreated by protein precipitation using acetonitrile, and then analyzed on a Zorbax Extend C₈column. The mobile phase consisted of acetonitrile-water-formic acid (60∶40∶0.2), at a flow-rate of 0.5 mL·min^-1. A Thermo Finnigan TSQ Quantum Ultra tandem mass spectrometer equipped with electrospray ionization source was used as detector and was operated in the positive ion mode. Selected reaction monitoring using the precursor to product ion combinations of m/z325 → m/z109 and m/z265 → m/z167 was performed to quantify citalopram and the internal standard, respectively. The pharmacokinetic parameters of citalopram in different formulations were calculated by non-compartment model. The linear calibration curves were obtained in the concentration range of 0.10-100 μg·L^-1. The lower limit of quantification was 0.10 μg·L^-1. The intra- and inter-day relative standard deviation (RSD) over the entire concentration range was less than 5.2%. Accuracy determined at three concentrations (0.25, 8.00 and 90.0 μg·L^-1 for citalopram) ranged from -4.7% to 1.3%. Each plasma sample was chromatographed within 3.0 min. The method was successfully used in bioequivalence study of citalopram in human plasma after oral administration of 20 mg citalopram. Calculated with AUC_{1-120 h}, the bioavailability of two formulations was (102.1±10.9)%. The method is rapid, selective, robust and is proved to be suitable for bioequivalence evaluation of different formulations containing citalopram.     

Ultra-performance liquid chromatography-tandem mass spectrometry method for the determination of nitrendipine in dog plasma and its application to a pharmacokinetic study of a solid self-emulsifying pellet formulation

A rapid, sensitive and selective ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was developed and validated for the quantitative determination of nitrendipine (NTD, CAS 39562-70-4) in dog plasma. Using propranolol hydrochloride (CAS 318-98-9) as an internal standard (IS), plasma samples pretreatment adopted a simple liquid-liquid extraction process with diethyl ether. Separation was carried out by a gradient elution on an Acquity UPLC BEH C18 column with a mobile phase consisting of water (containing 0.1% formic acid) and acetonitrile. Detection was performed by a triple-quadrupole mass spectrometry with positive electrospray ionization (ESI) as source ionization in multiple-reaction monitoring (MRM) mode at m/z 361.0 --> 315.0 for NTD and m/z 260.2 --> 116.0 for IS. The method demonstrated good linearity at the concentrations ranged from 0.1-200 ng/mL and the lower limit of quantification (LLOQ) of NTD was 0.1 ng/mL. The intra- and inter-day relative standard deviations (RSD) were less than 10%. The mean extraction recoveries of NTD and IS were 90.2% and 82.4%, respectively. Finally, the method was successfully applied to a pharmacokinetic study of home-made solid self-emulsifying pellets and conventional NTD tablets in beagle dogs following a single oral administration.     

A sensitive LC/MS/MS method using silica column and aqueous-organic mobile phase for the analysis of loratadine and descarboethoxy-loratadine in human plasma

A sensitive method using liquid chromatography with tandem mass spectrometric detection (LC/MS/MS) was developed and validated for the simultaneous analysis of antihistamine drug loratadine (LOR) and its active metabolite descarboethoxy-loratadine (DCL) in human plasma. Deuterated analytes, i.e. LOR-d(3) and DCL-d(3) were used as the internal standards (I.S.). Analytes were extracted from alkalized human plasma by liquid/liquid extraction using hexane. The extract was evaporated to dryness under nitrogen, reconstituted with 0.1% (v/v) of trifluoroacetic acid (TFA) in acetonitrile, and injected onto a 50 x 3.0 mm I.D. 5 microm, silica column with an aqueous-organic mobile phase consisted of acetonitrile, water, and TFA (90:10:0.1, v/v/v). The chromatographic run time was 3.0 min per injection and flow rate was 0.5 ml/min. The retention time was 1.2 and 2.0 min for LOR and DCL, respectively. The tandem mass spectrometric detection was by monitoring singly charged precursor-->product ion transitions: 383-->337 (m/z) for LOR, 311-->259 (m/z) for DCL, 388-->342 (m/z) for LOR-d(3), and 316-->262 (m/z) for DCL-d(3). The low limit of quantitation (LLOQ) was 10 pg/ml for LOR and 25 pg/ml for DCL. The inter-day precision of the quality control (QC) samples was 3.5-9.4% relative standard deviation (R.S.D.). The inter-day accuracy of the QC samples was 99.0-107.9% of the nominal values.     

Sample preparation and determination of gabapentin in venous and capillary blood using liquid chromatography-tandem mass spectrometry

An analytical method for the determination of gabapentin in serum obtained from venous blood samples has been developed using high-performance liquid chromatography (HPLC)-tandem mass spectrometry. In addition, a comparative study between capillary plasma samples and venous serum samples was carried out. This demonstrates the potential for the use of the described analytical system using very small amounts of blood. As internal standard (S)-(+)-alpha-amino-cyclohexane-propionic acid hydrate was used. Gabapentin and the internal standard are structural isomers, but have different m/z values for the fragments after collision induced dissolution. Gabapentin has 172-->154 and 172-->136 transitions and amino-cyclohexane-propionic acid hydrate has a 172-->126 transition which can be detected in tandem MS. Analysis of gabapentin was carried out on a C8 HPLC column using an isocratic mobile phase consisting of ammonium acetate (pH 3.0; 5mM)-methanol (96:4, v/v). The analytical method was validated for venous serum samples. Limit of detection was 1.6ng/ml and lower limit of quantification was 7.5ng/ml. R.S.D. values and bias values were within the range of acceptance for all concentration levels. The method developed for venous serum samples is being used in a gabapentin monitoring study using population pharmacokinetic modeling.     

Determination of capsaicin,nonivamide, and dihydrocapsaicin in blood and tissue by liquid chromatography-tandem mass spectrometry

A sensitive and selective liquid chromatography-tandem mass spectrometry (LC-MS-MS) method for the analysis of capsaicin, nonivamide, and dihydrocapsaicin in blood and tissue has been developed. The method utilized a one-step liquid-liquid extraction that yielded an approximate 90% recovery of capsaicinoids from blood. Chomatographic separation of the capsaicinoids was achieved using a reversed-phase high-performance liquid chromatography column and a stepwise gradient of methanol and distilled water containing 0.1% (v/v) formic acid. Identification and quantitation of the capsaicinoids was achieved using electrospray ionization-tandem mass spectrometry monitoring the precursor-to-product-ion transitions for the internal standard octanoyl vanillamide (m/z 280 --> 137), capsaicin (m/z 306 --> 137), dihydrocapsaicin (m/z 308 -->137), and nonivamide (m/z 294 --> 137). Calibration curves, 1.0 to 250 ng/mL, were constructed by plotting concentration versus peak-area ratio (analyte/internal standard) and fitting the data with a weighted quadratic equation. The accuracy of the assay ranged from 90% to 107% for all analytes. The intra-assay precision (%RSD) for capsaicin was 4% at 2.5 ng/mL, 3% at 10 ng/mL, and 7% at 100 ng/mL. The interassay precision (% RSD) for capsaicin was 6% at 2.5 ng/mL, 6% at 10 ng/mL, and 7% at 100 ng/mL. Similar values for inter- and intra-assay precision were obtained for nonivamide and dihydrocapsaicin. This method was used to assay for capsaicinoids in blood and tissue samples collected from rats exposed to capsaicinoids via nose-only inhalation. The concentration of capsaicin in these samples ranged from < 1.0 to 90.4 ng/mL in the blood, < 5.0 to 167 pg/mg in the lung, and < 2.0 to 3.4 pg/mg in the liver.     

液相色谱-质谱-质谱联用法测定猕猴血浆中阿德福韦液相色谱-质谱-质谱联用法测定猕猴血浆中阿德福韦

目的 建立测定猕猴血浆中阿德福韦(adefovir)的液相色谱-质谱-质谱联用法。方法 取血浆样品0.25 mL经甲醇沉淀蛋白后,以甲醇-水-甲酸(20∶80∶1)为流动相,用Diamonsil C₁₈柱分离,通过电喷雾离子化四极杆串联质谱,以选择离子反应监测方式进行检测。用于定量分析的离子反应分别为m/z 274→m/z 162(阿德福韦)和m/z 288→m/z 176［内标,9-(3-膦酸甲氧基丙基)腺嘌呤］。结果阿德福韦线性范围为0.02～4.00 mg·L^-1,最低定量限为20 μg·L^-1,日内、日间精密度(RSD)小于5.8%,准确度(RE)在±4.5%范围内。在临床前药代动力学研究中,应用此法测试了3只猕猴po给予阿德福韦地匹福酯(adefovir dipivoxil)后血浆中阿德福韦的浓度。结论该法操作简便,准确,适用于临床前药代动力学研究。     

LC/MS/MS法测定血浆中左羟丙哌嗪浓度及其药代动力学

目的建立测定血浆中左羟丙哌嗪的液相色谱-串联质谱法，考察左羟丙哌嗪在中国健康志愿者体内的药代动力学行为。方法血浆样品经液-液提取后，进行色谱分离，在三重四极杆串联质谱仪上，以多重反应离子监测(MRM)方式进行定量分析，用于监测的离子为m/z 237 → m/z 120（左羟丙哌嗪）和m/z 288 → m/z 58(佐米曲普坦，内标)。结果左羟丙哌嗪的最低定量浓度为0.25 μg·L^-1，线性范围为0.25-500.0 μg·L^-1，精密度与准确度符合生物样品分析要求。结论该法操作简便、快速、灵敏度高。可检测出健康志愿者po左羟丙哌嗪60 mg,其24 h后的血药浓度，适于临床药代动力学研究。     

High performance liquid chromatography-tandem mass spectrometric determination of rupatadine in human plasma and its pharmacokinetics

A simple, rapid, sensitive and selective liquid chromatographic-tandem mass spectrometric (LC-MS/MS) method was developed and validated for the quantification of rupatadine in human plasma using estazolam as internal standard (IS). Following liquid-liquid extraction, the analytes were separated using a mobile phase of methanol-ammonium acetate (pH 2.2; 5mM) (50:50, v/v) on a reverse phase C18 column and analyzed by a triple-quadrupole mass spectrometer in the positive ion and multiple reaction monitoring (MRM) mode, m/z 416-->309 for rupatadine and m/z 295-->267 for the IS. The assay exhibited a linear dynamic range of 0.1-100 ng/ml for rupatadine in human plasma. The lower limit of quantification (LLOQ) was 0.1 ng/ml with a relative standard deviation of less than 20%. Acceptable precision and accuracy were obtained for concentrations over the standard curve range. The validated LC-MS/MS method has been successfully applied to study the pharmacokinetics of rupatadine in healthy volunteers.     

Development of a method for comprehensive and quantitative analysis of armillarisin succinate ester in its medicinal preparations by liquid chromatography-ion trap mass spectrometry

A rapid and sensitive method for the identification and quantification of armillarisin succinate ester (ASE), which is a patent drug, is described. The method used liquid chromatography-ion trap mass spectrometry (LC-IT-MS/MS). The ASE standard solution was directly infused into IT-MS for collecting MS(n) spectra. The major fragment ions of ASE were confirmed by MS(n) at m/z 333, 233, 202, 189 and 163 in negative ion mode, and m/z 335, 217, 189,175 and 161 in positive mode, respectively. The possible main fragment ions cleavage pathways were studied between in positive-ion mode and in negative-ion mode. Quantification was performed using the transitions m/z 333 --> 233 in negative mode. The method is reliable and reproducible, and the detection limit is 2 ng/mL. The method was validated in the concentration range of 1.0 - 50 microg/mL, intra- and inter-day precision ranged from 1.98% to 4.06%, and the accuracy was 97.5-106.2%. The mean recovery of ASE was 97.2-105.3% with RSD less than 4.35%. A LC-IT-MS/MS has successfully applied to determine the ASE in its medicinal preparations.