电感耦合等离子体质谱法测定香精香料中的硼元素

采用微波消解-电感耦合等离子体质谱法(ICP-MS)测定香精香料中硼元素的含量。对微波消解样品前处理条件和仪器参数进行了优化,该方法硼元素检出限为1.005 ng/mL、平均回收率为106.1%、精密度为6.15%(n=5),并用茶叶国家标准物质(GBW10016)对分析方法进行了校准。该方法适合于香精香料中硼元素的测定。     

全蒸发顶空气相色谱法测定聚乙烯醇中甲醇的含量

建立了全蒸发顶空气相色谱法测定聚乙烯醇中甲醇含量的方法. 采用固定相为100%的二甲基聚硅氧烷石英毛细管柱,以氮气为载气,流速为1.0 mL/min,分流比为1:100,检测器温度为200 ℃,进样口温度为150 ℃,顶空进样,平衡温度为120 ℃,平衡时间为90 min,相关系数r为0.9979. 在此色谱条件下被测物均能得到很好的分离,甲醇峰面积与检测浓度呈良好的线性关系. 方法的检测限为0.011 mg,回收率为98.15%. 采用改变气固相比的方法测定了顶空色谱下的气固相分配系数,在0.02~0.4之间,方法符合全蒸发顶空气相色谱法应用条件. 实验建立的色谱方法灵敏、准确、简单、方便、高效. 方法可同时对9个样品进行测定,适合于企业大批量聚乙烯醇中甲醇含量的测定.     

气相色谱法检测面粉中磷化氢残留量

通过顶空气相色谱外标法快速、准确的测定粮食中残留的磷化氢含量.采用Porapak-Q填充柱,火焰光度检测器(FPD)进行分析测定.当磷化氢浓度在2.5~25.0 ng/mL范围内时,呈现良好线性关系(R2=0.9999).磷化氢含量为0.01和0.10μg/g时的平均加标回收率分别为93.7%和96.5%.此方法的操作简便,稳定性好,对同一浓度样品6次平行测定的RSD为0.9%.根据样品的质量,此方法的检出限可达到0.001μg/g,可作为粮食中磷化氢残留量快速测定.     

顶空气相色谱法测定制药工业污水中的甲苯

采用顶空气相色谱法测定制药工业污水中的甲苯含量.顶空瓶中的制药工业污水样品在顶空仪上加热平衡后,其顶空气体进入气相色谱仪中分离和检测.方法的检出限为0.002 mg/mL,测定结果的相对标准偏差为3.27%～9.26%(n=5),回收率为92.7%～97.0%.与GB/T 11890-1989相比,本方法操作简便快速、检测限低,具有较高的进样稳定性,结果计算更加科学准确.     

顶空-气相色谱法测定B-100生物柴油中游离甲醇含量

建立了顶空-气相色谱测定B-100生物柴油中游离甲醇含量的方法.B-100生物柴油样品使用N,N-二甲基乙酰胺溶解,90℃下顶空平衡45 min,在HP-INNOWAX色谱柱上进行分离和测定.方法建立了外标法定量的标准曲线,相关系数r大于0.999,样品中甲醇质量分数的检出限为0.005%.对实际样品进行检测,相对标准偏差为4.96%~6.83%(n=6),加标回收率为92.0%~110%.方法操作简单、快速、重复性好,适用于B-100生物柴油中游离甲醇含量的测定.     

顶空进样GC-SIM-MS测定硝唑尼特中溶剂残留甲醇含量

利用气相色谱-选择离子监测质谱联用仪(GC-SIM-MS)测定硝唑尼特样品中溶剂残留甲醇的含量,顶空进样,温度为70℃,时间为20 min.SIM定量离子m/z 32,参考离子m/z 31,30和29.甲醇质量浓度在0.5~100μg/m L内呈良好的线性(R~2=0.999 92).方法相对标准偏差为2.49%~4.85%,样品加标回收在94.5%~102.8%之间,检测限为0.5μg/m L,符合定量分析的要求.     

超高效液相色谱-串联质谱法测定血浆与尿液中14种麻痹性贝类毒素北大核心CSCD

人体生物基质中麻痹性贝类毒素的检测对其引起的食物中毒诊断和救治具有重要意义。研究建立了超高效液相色谱-串联质谱法测定血浆、尿液中14种麻痹性贝类毒素的分析方法。实验比较了不同固相萃取柱的影响,优化了前处理条件和色谱条件,血浆样品采用0.2 mL水、0.4 mL甲醇、0.6 mL乙腈提取后直接上机测定,尿液样品采用0.2 mL水、0.4 mL甲醇、0.6 mL乙腈提取,聚酰胺(PA)固相萃取柱净化后上机测定。采用Poroshell 120 HILIC-Z色谱柱(100 mm×2.1 mm,2.7μm)对14种贝类毒素进行分离,流动相为含0.1%(v/v)甲酸的5 mmoL/L甲酸铵缓冲溶液和0.1%(v/v)甲酸乙腈溶液,流速为0.50 mL/min。在电喷雾模式(ESI)下进行正负离子扫描,采用多反应监测(MRM)模式检测,外标法定量。结果表明,对于血浆和尿液样品,14种贝类毒素分别在0.24~84.06 ng/mL范围内线性关系良好,相关系数均大于0.995。尿液检测的定量限为4.80~34.40 ng/mL,血浆检测的定量限为1.68~12.04 ng/mL。尿液和血浆样品在1、2和10倍定量限加标水平下平均回收率为70.4%~123.4%,日内精密度为2.3%~19.1%,日间精密度为4.0%~16.2%。应用建立的方法对腹腔注射14种贝类毒素小鼠血浆和尿液进行测定,20份血浆样本中检出含量分别为19.40~55.60μg/L和8.75~13.86μg/L。该方法操作简便,样品取样量少,方法灵敏度高,适用于血浆和尿液中麻痹性贝类毒素的快速检测。     

液相色谱–质谱法测定血清中左乙拉西坦含量

建立测定血清中左乙拉西坦浓度的液相色谱–质谱方法。血清样品用甲醇提取,离心分离除去蛋白,采用液相色谱–质谱法测定其中左乙拉西坦的含量。流动相为甲醇–0.1%甲酸(体积比为80∶20),色谱柱为Agilent C18柱(100 mm×4.6 mm,3.5μm)。左乙拉西坦含量在1 000~100 000 ng/m L范围内与色谱峰面积线性关系良好,线性相关系数r2=0.999,检出限为10 ng/m L。测定结果的相对标准偏差为0.93%(n=6),样品加标回收率为99.4%~101.3%。该方法具有较高的灵敏度、准确度和良好的精密度,适合血清中左乙拉西坦含量的测定。     

顶空气相色谱法测定盐酸托莫西汀中有机溶剂残留量的研究

建立了盐酸托莫西汀中有机溶剂残留量的顶空气相色谱分析方法.选用大口径HP-快速GC残留溶剂柱为分离柱,FID为检测器,外标法进行定量,并对顶空平衡温度、平衡时间、供试品溶液的制备方法对残留有机溶剂测定的影响进行了研究.甲醇、乙醚、正己烷、乙酸乙酯、四氢呋喃的线性范围分别为 0.41～8.10 μg/mL(r=0.9999)、0.15～3.00 μg/mL(r=0.9995)、0.20～4.01 μg/mL(r=0.9991)、0.32～6.35 μg/mL(r=0.9999)、0.36～7.11 μg/mL(r=0.9999);平均回收率范围96.30%～105.47%,精密度RSD(n=6)2.1%～3.7%;检出限分别为0.2、0.008、0.003、0.04、0.04 μg/mL.     

微波消解-微波等离子体炬原子发射光谱法测定膨化食品中铅和铝

膨化食品样品经微波消解处理,用微波等离子体炬原子发射光谱法(MPT-AES)测定其中铅和铝的含量。详细考察了分析谱线、微波功率、载气流量、工作气流量等实验参数对元素测定的影响,在最佳条件下测得铅和铝的检出限分别为4.7ng/mL和20.8ng/mL,其线性范围分别为0.01~20μg/mL和0.5~300μg/mL,样品加标回收率为96.4%~104.1%,精密度为1.06%~4.65%。结果表明,MPT-AES测定膨化食品中铅和铝的含量方法简便、高效、消耗试剂少、污染少、准确度高。     

A sensitive LC–MS/MS‐based bioanalytical method for quantification of salviaflaside and rosmarinic acid in rat plasma and its application in a pharmacokinetic study

A selective and sensitive liquid chromatography tandem mass spectrometry method was developed for the simultaneous determination of salviaflaside and rosmarinic acid in rat plasma. Sample preparation was carried out through liquid–liquid extraction with ethyl acetate using curculigoside as internal standard (IS). The analytes were determined by selected reaction monitoring operated in the positive ESI mode. Chromatographic separation was performed on an Agilent Eclipse Plus C₁₈ column (100 × 4.6 mm, 1.8 μm) with a mobile phase consisting of methanol–water–formic acid (50:50:0.1, v/v/v) at a flow rate of 0.3 mL/min. The run time was 1.9 min per sample and the injection volume was 5 μL. The method had an LLOQ of 1.6 ng/mL for salviaflaside and 0.94 ng/mL for rosmarinic acid in plasma. The linear calibration curves were fitted over the range of 1.6–320 ng/mL for salviaflaside and 0.94–188 ng/mL for rosmarinic acid in plasma with correlation coefficients (r²) >0.99. Intra‐ and inter‐day precisions (relative standard deviation) were < 13.5%, and accuracies (relative error) were between −8.6% and 14.5% for all quality control samples. The method was validated and applied to the pharmacokinetics of salviaflaside and rosmarinic acid in plasma after oral administration of Prunella vulgaris extract to rats.     

Simultaneous quantification of sildenafil and N‐desmethyl sildenafil in human plasma by UFLC coupled with ESI‐MS/MS and pharmacokinetic and bioequivalence studies in Malay population

A simple, rapid, specific and reliable UFLC coupled with ESI‐MSMS assay method to simultaneously quantify sildenafil and N‐desmethyl sildenafil, with loperamide as internal standard, was developed. Chromatographic separation was performed on a Thermo Scientific Accucore C₁₈ column with an isocratic mobile phase composed of 0.1% v/v formic acid in purified water–methanol (20:80, v/v), at a flow rate of 0.3 mL/min. Sildenafil, N‐desmethyl sildenafil and loperamide were detected with proton adducts at m/z 475.4 > 58.2, 461.3 > 85.2 and 477.0 > 266.1 in multiple reaction monitoring positive mode, respectively. Both analytes and internal standard were extracted by diethyl ether. The method was validated over a linear concentration range of 10–800 ng/mL for sildenafil and 10–600 ng/mL for N‐desmethyl sildenafil with correlation coefficient (r²) ≥0.9976 for sildenafil and (r²) ≥0.9992 for N‐desmethyl sildenafil. The method was precise, accurate and stable. The proposed method was applied to study the bioequivalence between a 100 mg dose of two pharmaceutical products: Viagra (original) and Edyfil (generic) products. AUC_0–t, C_max and T_max were 2285.79 ng h/mL, 726.10 ng/mL and 0.94 h for Viagra and 2363.25 ng h/mL, 713.91 ng/mL and 0.83 hour for Edyfil. The 90% confidence interval of these parameters of this study fall within the regulatory range of 80–125%, hence they are considered as bioequivalent. Copyright © 2014 John Wiley & Sons, Ltd.     

A liquid chromatography–mass spectrometric method for the quantification of azithromycin in human plasma

A liquid chromatographic mass spectrometric assay for the quantification of azithromycin in human plasma was developed. Azithromycin and imipramine (as internal standard, IS) were extracted from 0.5 mL human plasma using extraction with diethyl ether under alkaline conditions. Chromatographic separation of drug and IS was performed using a C₁₈ column at room temperature. A mobile phase consisting of methanol, water, ammonium hydroxide and ammonium acetate was pumped at 0.2 mL/min. The mass spectrometer was operated in positive ion mode and selected ion recording acquisition mode. The ions utilized for quantification of azithromycin and IS were m/z 749.6 (M + H) ⁺ and m/z 591.4 (fragment) for azithromycin, and 281.1 m/z for internal standard; retention times were 6.9 and 3.4 min, respectively. The calibration curves were linear (r² > 0.999) in the concentration ranges of 10–1000 ng/mL. The mean absolute recoveries for 50 and 500 ng/mL azithromycin and 1 µg/ mL IS were >75%. The percentage coefficient of variation and mean error were <11%. Based on validation data, the lower limit of quantification was 10 ng/mL. The present method was successfully applied to determine azithromycin pharmacokinetic parameters in two obese volunteers. The assay had applicability for use in pharmacokinetic studies. Copyright © 2013 John Wiley & Sons, Ltd.     

Quantification of 3‐n‐butylphthalide in beagle plasma samples by supercritical fluid chromatography with triple quadruple mass spectrometry and its application to an oral bioavailability study

A high‐throughput, rapid, sensitive, environmentally friendly, and economical supercritical fluid chromatography with triple quadruple mass spectrometry method was established and validated for the first time to determine a cerebral stroke treatment drug named 3‐n‐butylphthalide in dog plasma. Plasma samples were prepared by protein precipitation with methanol and the analytes were eluted on an ACQUITY UPC^2TM HSS‐C₁₈ SB column (3 × 100 mm, 1.8 μm) maintained at 50°C. The mobile phase comprised supercritical carbon dioxide/methanol (90:10, v/v) at a flow rate of 1.5 mL/min, the compensation solvent was methanol at a flow rate of 0.2 mL/min and the total run time was 1.5 min per sample. The detection was carried out on a tandem mass spectrometer with an electrospray ionization source. Calibration curves were linear over the concentration range of 1.02–1021.00 ng/mL (r² ≥ 0.993) with the lower limit of quantification of 1.02 ng/mL. The intra‐ and inter‐day precision values were below 15% and the accuracy was from 97.90 to 103.70% at all quality control levels. The method was suitable for a pharmacokinetic study of 3‐n‐butylphthalide in beagle dogs.     

Quantification of heteroclitin D in rat plasma: validation of an LC/MS/MS method and its application in a preclinical pharmacokinetic study

A rapid, sensitive and specific liquid chromatography tandem mass spectrometry (LC/MS/MS) method was developed and validated for the quantification of heteroclitin D in rat plasma after using gambogic acid as internal standard (IS). Chromatographic separation was done on a Thermo Hypersil GOLD column (30 × 2.1 mm, 3 µm) using a mobile phase consisting of methanol–water–formic acid (80:20:0.1, v/v/v). The mass spectrometer worked with positive electrospray ionization in multiple reaction monitoring mode, using target ions at [M + H]⁺ m/z 483.3 for heteroclitin D and [M + H]⁺ m/z 629.3 for the IS. The standard curve was linear (R² ≥0.995) over the concentration range 9.98–2080 ng/mL and had good back‐calculated accuracy and precision. The intra‐ and interday precision and accuracy determined on three quality control samples (29.94, 166.4 and 1872 ng/mL) were ≤12.8 and –8.9–3.6%, respectively. The extraction recovery was ≥88.2% and the lower limit of quantification was 9.98 ng/mL. The method was successfully applied to evaluate pharmacokinetics of heteroclitin D in Sprague–Dawley rats following a single intravenous bolus injection of 2.0 mg/kg heteroclitin. Copyright © 2014 John Wiley & Sons, Ltd.     

Liquid chromatography–tandem mass spectrometric assay for the determination of vaccarin in rat plasma: application to a pharmacokinetic study

Vaccarin, a flavonoid glycoside, is considered one of the major active constituents of Vaccaria segetalis. A simple and specific liquid chromatography–tandem mass spectrometric method was developed and validated for quantifying vaccarin in rat plasma following intravenous dosing. Plasma samples were precipitated with methanol and separated on a Venusil‐C₁₈ analytical column (2.1 × 50 mm, 5 µm particles) with gradient elution consisting of methanol and 0.1% (v/v) formic acid as the mobile phase. The detection was performed on an Agilent Triple Quad LC/MS with electrospray ionization inlet in the positive multiple reaction monitoring mode. Good linearity was achieved over the concentration range of 12.5–25,000 ng/mL (r² > 0.99). Intra‐ and inter‐day precisions were <9.1%, and accuracy ranged from ?2.8 to 8.7%. The lower limit of quantification for vaccarin was 12.5 ng/mL, and the analyte was stable under various storage conditions. This validated method was successfully applied to the preliminary pharmacokinetic studies of vaccarin following intravenous administrations of 1.21, 2.41, and 4.82 mg/kg vaccarin in rats. Copyright © 2014 John Wiley & Sons, Ltd.     

Determination of tubuloside B by LC‐MS/MS and its application to a pharmacokinetic study in rats

Tubuloside B, a novel neuroprotective phenylethanoid, is a major active constituent of Cistanche tubulosa and Cistanche deserticola. A specific and sensitive liquid chromatography tandem mass spectrometry (LC‐MS/MS) method has been developed and validated for the quantification of tubuloside B in rat plasma. Sample preparation was conducted through a protein‐precipitation extraction with methanol using tubuloside A as internal standard (IS). Chromatographic separation was achieved using a Capcell Pak C₁₈ column (2.0 × 50 mm, 5 μm) with a mobile phase of methanol–10 mm ammonium acetate buffer (70:30, v/v) in an isocratic elution. Mass spectrometry analysis was performed in negative ionization mode with selected reaction monitoring transitions at m/z 665.1 → 160.9 for tubuloside B, and m/z 827.1 → 160.9 for IS. Calibration curves were linear over the range of 1.64–1640 ng/mL for plasma samples samples (R² > 0.990). The lower limit of quantification (LLOQ) was 1.64 ng/mL. The intra‐ and inter‐day accuracy was between 92.3 and 113.0% with the RSD <9.23% at all LLOQ and quality control levels. Finally, this method was successfully applied in the pharmacokinetics study of tubuloside B after intravenous administration.     

Simultaneous determination and pharmacokinetic study of three flavonoid glycosides in rat plasma by LC–MS/MS after oral administration of Rubus chingii Hu extract

A simple and sensitive liquid chromatography tandem mass spectrometry (LC–MS/MS) method was developed for the simultaneous determination of isoquercitrin, kaempferol‐3‐O‐rutinoside and tiliroside in rat plasma. Plasma samples were deproteinized with methanol and separated on a Hypersil Gold C₁₈ column (2.1 × 50 mm, i.d., 3.0 μm) using gradient elution with the mobile phase of water and methanol at a flow rate of 0.4 mL/min. Mass spectrometric detection was performed with negative ion electrospray ionization in selected reaction monitoring mode. All analytes showed good linearity over their investigated concentration ranges (r² > 0.99). The lower limit of quantification was 1.0 ng/mL for isoquercitrin and 2.0 ng/mL for kaempferol‐3‐O‐rutinoside and tiliroside, respectively. Intra‐ and inter‐day precisions were <8.2% and accuracy ranged from −11.5 to 9.7%. The mean extraction recoveries of analytes and IS from rat plasma were >80.4%. The assay was successfully applied to investigate the pharmacokinetic study of the three ingredients after oral administration of Rubus chingii Hu to rats.     

Quantification of morusin using LC–MS in rat plasma: Application to a pharmacokinetic study

A sensitive LC–MS method was developed for the quantification of morusin in rat plasma using praeruptorin C as internal standard. After extraction with diethyl ether, post‐treatment samples were chromatographed on a Hypersil C₁₈ column. An isocratic mobile phase consisting of methanol–water (70:30, v /v) was applied at a flow rate of 0.4 mL/min. Detection was performed via electrospray ionization source with positive ion mode using selected ion monitoring mode at m/z 443.1 for morusin and m/z 451.0 for IS. Acceptable linearity (r ² ≥ 0.99) was observed over the concentration range of 1.5–800 ng/mL. This method was successfully applied in the pharmacokinetics study of morusin in rats.     

Quantitative determination of meloxicam in dog plasma by high performance liquid chromatography–tandem mass spectrometry and its application in a pharmacokinetic study

A rapid, selective and sensitive high‐performance liquid chromatography–tandem mass spectrometry (HPLC‐MS/MS) method was developed to determine meloxicam in beagle dog plasma. Sample pretreatment involved a one‐step protein precipitation with methanol of 0.1 mL plasma. Analysis was performed on a Venusil ASB‐C₁₈ column with mobile phase consisting of methanol–water (containing 0.1% formic acid) (75:25, v/v). The detection was performed on a triple quadrupole tandem mass spectrometer by multiple reaction monitoring mode via electrospray ionization source. Each plasma sample was chromatographed within 4.1 min. The linear calibration curves for meloxicam was obtained in the concentration range of 10.3–4.12 × 10³ ng/mL (r ≥ 0.99). The intra‐ and inter‐day precisions (relative standard deviation) were ≤ 15%, and accuracy (relative error) was within ±7.3%. The method herein described was fully validated and successfully applied to the pharmacokinetic study of meloxicam tablets in beagle dog.