Determination of cilnidipine, a new calcium antagonist, in human plasma using high performance liquid chromatography with tandem mass spectrometric detection

A rapid, sensitive and reliable high performance liquid chromatographic method coupled with tandem mass spectrometry (HPLC–MS/MS) has been developed and validated for the determination of cilnidipine, a relatively new calcium antagonist, in human plasma. The reversed-phase chromatographic system was interfaced with a TurboIonSpray (TIS) source. Nimodipine was employed as the internal standard (IS). Sample extracts following protein precipitation were injected into the HPLC–MS/MS system. The analyte and IS were eluted isocratically on a C18 column, with a mobile phase consisting of CH₃OH and NH₄Ac (96:4, v/v). The ions were detected by a triple quadrupole mass spectrometric detector in the negative mode. Quantification was performed using multiple reaction monitoring (MRM) of the transitions m/z 491.2 → 122.1 and m/z 417.1 → 122.1 for cilnidipine and for the IS, respectively. The analysis time for each run was 3.0 min. The calibration curve fitted well over the concentration range of 0.1–10 ng mL⁻¹, with the regression equation Y = (0.103 ± 0.002)X + (0.014 ± 0.003) (n = 5), r = 0.9994. The intra-day and inter-day R.S.D.% were less than 12.51% at all concentration levels within the calibration range. The recoveries were between 92.71% and 97.64%. The long-term stability and freeze-thaw stability were satisfying at each level. The present method provides a modern, rapid and robust tool for pharmacokinetic studies of cilnidipine.     

Determination of itopride in human plasma by liquid chromatography coupled to tandem mass spectrometric detection: application to a bioequivalence study

A simple method using a one-step liquid-liquid extraction (LLE) with butyl acetate followed by high-performance liquid chromatography (HPLC) with positive ion electrospray ionization tandem mass spectrometric (ESI-MS/MS) detection was developed for the determination of itopride in human plasma, using sulpiride as an internal standard (IS). Acquisition was performed in multiple reaction monitoring (MRM) mode, by monitoring the transitions: m/z 359.5 > 166.1 for itopride and m/z 342.3 > 111.6 for IS, respectively. Analytes were chromatographed on an YMC C₁₈ reverse-phase chromatographic column by isocratic elution with 1 mM ammonium acetate buffer-methanol (20: 80, v/v; pH 4.0 adjusted with acetic acid). Results were linear (r² = 0.9999) over the studied range (0.5-1000 ng mL⁻¹) with a total analysis time per run of 2 min for LC-MS/MS. The developed method was validated and successfully applied to bioequivalence studies of itopride hydrochloride in healthy male volunteers.     

高效液相色谱-电感耦合等离子体质谱联用检测食品中的五种硒形态

建立了高效液相色谱-电感耦合等离子体质谱(HPLC-ICP-MS)联用检测硒酸盐(SeVI)、亚硒酸盐(SeIV)、硒代蛋氨酸(SeMet)、硒代胱氨酸(SeCys2)和硒代乙硫氨酸(SeEt)的方法。采用Hamilton PRP X-100色谱柱（250 mm×4.6 mm, 5 μm）,使用5 mmol/L的柠檬酸溶液(pH 4.5)作为流动相,电感耦合等离子体质谱(ICP-MS)检测,在21 min内可以完全分离5种硒形态。各形态硒的线性相关系数均大于0.9995, SeVI、SeIV、SeMet、SeCys2、SeEt的检出限分别为0.4、0.4、5.6、0.9、1.2 μg/L。探讨了不同提取方法的提取效果,鲜蘑菇和猪肉样品加标回收实验表明,对水溶性良好的无机硒和硒代蛋氨酸而言,采用柠檬酸溶液提取的效果非常好,SeIV和SeVI的回收率均在100%左右,SeMet的回收率为85.0%～95.3%;用蛋白酶水解提取,SeCys2和SeEt的回收率为79.9%～91.5%。该方法可完全满足食品中这5种硒形态的准确定量分析。     

微波灰化-高效液相色谱-电感耦合等离子体质谱(ICP-MS)法测定茶叶中的铬酸铅

为了准确测定茶叶中铬酸铅的含量,为市场监管提供判断依据,本文建立了微波灰化-高效液相色谱-电感耦合等离子体质谱仪测定茶叶中铬酸铅的方法。茶叶样品经微波灰化仪在500 ℃的条件下,灰化50 min后,用0.25 mol·L-1的NaOH和0.14 mol·L-1的Na2CO3混合碱性提取液在90 ℃-95 ℃温度下不间断搅拌提取10 min,提取液经色谱柱分离后,用ICP-MS测定52Cr。研究表明该方法在5.00 μg·L-1-500 μg·L-1范围内,线性良好,相关系数为0.9998,方法检出限低至2.5 mg·kg-1,三水平加标回收率为91.30 %～95.33 %,精密度在1.14 %～1.99 %之间。与电炉灼烧茶叶相比,微波灰化茶具有检出限低,精密度高,准确度良好等特性,能够满足茶叶中铬酸铅的测定。 关键词 微波灰化;高效液相色谱-电感耦合等离子体质谱法;铬酸铅;茶叶     

超高效液相色谱-电喷雾串联质谱法测定饲料中残留的三聚氰胺

饲料样品经1%三氯乙酸-二甲基亚砜提取,Waters Oasis MCX柱净化,超高效液相色谱分离,最终采用电喷雾串联四极杆质谱进行检测。结果表明,三聚氰胺在饲料中的含量范围为10～5000 μg/kg时,线性关系良好(r＞0.99)。在10～100 μg/kg 的添加水平范围内的平均回收率为83%～94%,相对标准偏差为4.2%～6.5%。该方法的检出限为10 μg/kg。     

高效液相色谱-电喷雾串联质谱法测定饲料中的N-氨基甲酰-L-谷氨酸

建立了高效液相色谱-电喷雾串联质谱(HPLC-ESI-MS/MS)测定饲料中N-氨基甲酰-L-谷氨酸(NCG)含量的方法。饲料样品经甲醇提取、混合型强阴离子交换反相固相萃取(PXA)柱净化、HPLC分离后,采用ESI-MS/MS在正离子多反应监测(MRM)模式下进行检测,以碎片离子m/z 148.0和m/z 84.0进行定性,以碎片离子m/z 130.0进行定量。NCG的检出限(S/N >3)为24 μg/kg,定量限(S/N >10)为80 μg/kg,在20~1000 μg/L的质量浓度范围内峰面积与含量的线性关系良好,相关系数为0.9999。对饲料中NCG在80、200、500 mg/kg等3个添加水平下的回收率进行了测定,分别为104.0%、103.5%、95.3%,相对标准偏差分别为7.5%、6.3%、5.8%。结果表明,该方法操作简单,净化效果好,快速,灵敏度和准确度高,符合对饲料样品中NCG检测分析的要求。     

高效液相色谱-串联质谱法测定动物源食品中粘杆菌素、多粘菌素B的残留量

建立了动物源食品中粘杆菌素和多粘菌素B残留的高效液相色谱-串联质谱(HPLC-MS/MS)测定方法。样品用V(10%三氯乙酸水溶液):V(乙腈)=30:70提取,Oasis WCX SPE柱净化,LC-MS/MS电喷雾正离子多反应监测模式(ESI+-MRM)检测。分析物在0～250μg/kg的浓度范围内呈良好线性,线性相关系数>0.995。方法的定量限为10μg/kg。方法在三个添加水平的平均回收率在71.6%～78.9%之间,相对标准偏差在6.2%～12%之间。方法适用于动物源食品中粘杆菌素和多粘菌素B的定量及确证检测。     

Quantitative analysis of the P-glycoprotein inhibitor Elacridar (GF120918) in human and dog plasma using liquid chromatography with tandem mass spectrometric detection

A liquid chromatographic/tandem mass spectrometric (LC/MS/MS) method for the determination of the P-glycoprotein and breast cancer resistance protein inhibitor Elacridar in human and dog plasma is described. The internal standard was stable isotopically labelled Elacridar. Sample pretreatment involved liquid-liquid extraction with tert-butyl methyl ether. Analysis of Elacridar and internal standard was performed by reversed-phase LC on a basic stable minibore analytical column with an eluent consisting of acetonitrile and aqueous ammonia. An API-2000 triple-quadrupole mass spectrometer with an electrospray ion source was used in the positive-ion multiple reaction monitoring mode. The run time per sample was only 6 min. The method is sensitive and specific, with a dynamic range from 1 to 500 ng ml(-1) from 100 microl of human or dog plasma. The accuracy of the method was within 15% bias and the precision was lower than 15% for all tested concentration levels and in both matrices. The method is simple and the liquid-liquid extraction produces clean samples. This method was successfully applied to support the pharmacokinetics of a clinical trial in which orally applied Elacridar was used as a bioavailability enhancer.     

Sensitive and rapid analytical method for the quantification of glucosamine in human plasma by ultra high performance liquid chromatography with tandem mass spectrometry

A highly sensitive and rapid ultra high performance liquid chromatography with tandem mass spectrometry method has been developed and validated for the determination of glucosamine in human plasma using miglitol as the internal standard. Special attention was paid to achieve the high throughput and sensitivity of the established method, and the absence of a matrix effect on the analytes. The sample preparation procedure involved a simple deproteinization step. The chromatographic separation was achieved on a Waters ACQUITY HSS Cyano column using a mixture of acetonitrile/2 mM ammonium acetate solution containing 0.03% formic acid (80:20, v/v) as the mobile phase with a very short run time of 1.5 min. This method was validated over the concentration range of 10–3000 ng/mL for glucosamine. The intra‐ and inter‐batch precision was <13.9% for the low, medium, and high quality control samples. The established method is highly sensitive with a lower limit of quantification of 10 ng/mL, low enough to determine the circadian rhythm on endogenous glucosamine level in human plasma, which has not been reported in detail until now. The method was successfully applied to characterize the pharmacokinetic profile of glucosamine in healthy volunteers following a single oral administration of 750 or 1500 mg glucosamine hydrochloride.     

高效液相色谱-串联质谱测定猪肉中3种β-受体激动剂残留量

建立一种同时测定猪肉中3种β-受体激动剂残留量的高效液相色谱-电喷雾串联质谱(HPLC-ESI-MS/MS)确证分析方法。样品经β-葡萄糖醛酸酶/芳基硫酸酯酶酶解、乙酸铵缓冲液提取和MCX固相萃取柱净化,采用Agilent ZorbaxSB-C18(2.1mm×150mm,3.5μm)色谱柱,0.1%的甲酸水溶液、甲醇和乙腈作为流动相进行洗脱,高效液相色谱分离,电喷雾离子源电离,正离子多反应监测模式进行检测,内标法定量。3种药物在0.05～1μg/kg浓度范围内线性良好,相关系数r均大于0.999,0.05、0.1、0.5μg/kg3个浓度水平的添加回收率在89.7%～106.7%之间,相对标准偏差为2.4%～8.6%,3种药物的定量限均为0.05μg/kg。方法适用于猪肉中β-受体激动剂残留的确证分析。     

Determination of bromazepam in human plasma by high-performance liquid chromatography with electrospray ionization tandem mass spectrometric detection: application to a bioequivalence study

A simple method using a one-step liquid-liquid extraction (LLE) followed by high-performance liquid chromatography (HPLC) with positive ion electrospray ionization tandem mass spectrometric (ESI-MS/MS) detection was developed for the determination of bromazepam in human plasma, using lorazepam as internal standard. The acquisition was performed in the multiple reaction monitoring mode, monitoring the transitions: m/z 316 > 182 for bromazepam and m/z 321 > 275 for lorazepam. The method was linear over the studied range (1-100 ng ml(-1)), with r(2) > 0.98, and the run time was 2.5 min. The intra- and inter-assay precisions were 2.7-14.6 and 4.1-17.3%, respectively and the intra- and inter-assay accuracies were 87-111 and 75.8-109.5%, respectively. The mean recovery was 73.7%, ranging from 64.5 to 79.7%. The limit of quantification was 1 ng ml(-1). At this concentration the mean intra- and inter-assay precisions were 14.6 and 7.1%, respectively, and the mean intra- and inter-assay accuracies were 102.5 and 104%, respectively. Bromazepam stability was evaluated and the results showed that the drug is stable in standard solution and in plasma samples under typical storage and processing conditions. The method was applied to a bioequivalence study in which 27 healthy adult volunteers (14 men) received single oral doses (6 mg) of reference and test bromazepam formulations, in an open, two-period, randomized, crossover protocol. The 90% confidence interval of the individual ratios (test formulation/reference formulation) for C(max) (peak plasma concentration), AUC(0-96) and AUC(0-inf) (area under the plasma concentration versus time curve from time zero to 96 h and to infinity, respectively) were within the range 80-125%, which supports the conclusion that the test formulation is bioequivalent to the reference formulation regarding the rate and extent of bromazepam absorption.     

Simultaneous determination of three bufadienolides in rat plasma after intravenous administration of bufadienolides extract by ultra performance liquid chromatography electrospray ionization tandem mass spectrometry

A novel, rapid and specific ultra performance liquid chromatography electrospray ionization tandem mass spectrometry (UPLC-ESI-MS/MS) method has been developed for simultaneous determination and pharmacokinetic studies of three bufadienolides (bufalin, cinobufagin and resibufogenin) in rat plasma. The analytes, bufalin, cinobufagin, resibufogenin and the internal standard, diphenhydramine were extracted from rat plasma samples by a one-step liquid–liquid extraction and separated on an ACQUITY UPLC™ BEH C₁₈ column with gradient elution using a mobile phase composed of acetonitrile and water (containing 0.1% formic acid) at a flow rate of 0.20 mL min⁻¹. Detection was carried out on a triple-quadrupole tandem mass spectrometer in the multiple reaction monitoring (MRM) mode via an electrospray ionization (ESI) interface. The three bufadienolides could be simultaneously determined within 3.0 min. Linear calibration curves were obtained over the concentration ranges of 1.0–200 ng mL⁻¹ for all the analytes. The intra- and inter-day precisions (relative standard deviation (R.S.D.)) were less than 11.35 and 10.87%, respectively. The developed method was applied for the first time to the pharmacokinetic studies of bufadienolides in rats following a single intravenous administration of 2.10 mg kg⁻¹ bufadienolides.     

液相色谱-电喷雾串联质谱法测定人血浆中的艾芬地尔

建立了测定人血浆中艾芬地尔的液相色谱-串联质谱方法。血浆样品用乙酸乙酯液-液提取后,以甲醇-6 mmol/L乙酸铵溶液(pH 7.40)(体积比为90∶10)为流动相进行分离。在Q TRAPTM串联质谱仪上,以选择性反应离子监测(SRM)方式进行定量分析,用于监测的离子为m/z 326.1→308.2 (艾芬地尔)和m/z 531.0→82.1 (酮康唑,内标)。在6 min内完成了艾芬地尔的检测,工作曲线的线性范围为0.25～50 μg/L,日内、日间精密度分别小于2.7%和6.5%,平均回收率为101.3%～105.0%,检测限为0.08 μg/L。本方法灵敏度高,特异性好,可以用于临床试验的血浆样品的检测。     

超高压液相色谱-串联质谱测定茶叶中10种极性农药残留

建立了绿茶、乌龙茶、红茶和普洱茶中8种氨基甲酸酯和2种烟碱类农药等10种极性农药残留超高压液相色谱-串联质谱(UPLC-MS/MS)检测方法。茶叶样品经水润湿15 min后,乙腈提取,Carbon/NH2固相萃取净化,乙腈-甲苯(3:1V/V)淋洗。UPLC-MS/MS采用电喷雾电离(ESI),多反应监测模式(MRM)分析。方法在7.5,15,30μg/kg添加水平上回收率达到72.2%～92.5%,RSD≤9.2%。10种农药的基质效应因不同农药和不同种类茶叶基质存在较大差异,且均表现为基质抑制效应,因此校正工作液需采用相似茶叶空白基质配制。方法的定量限(LOQ)均达到7.5μg/kg.     

Determination of teniposide in rat plasma by ultra performance liquid chromatography electrospray ionization tandem mass spectrometry after intravenous administration

A novel, specific and rapid ultra performance liquid chromatography electrospray ionization tandem mass spectrometry method has been developed and validated for determination of teniposide in rat plasma. A one‐step liquid–liquid extraction method was used and the separation was carried out on an Acquity UPLC^TM BEH C₁₈ column with gradient elution using a mobile phase composed of acetonitrile and water (containing 0.1% formic acid) at a flow rate of 0.20 mL/min. A triple quadrupole tandem mass spectrometer in multiple‐reaction monitoring mode via an electrospray ionization interface was used for the detection of teniposide. The detection was complete within 3.0 min. A linear calibration curve was obtained over the concentration range 10–10,000 ng/mL for teniposide, with a lower limit of quantification of 10 ng/mL. The intra‐day precision and inter‐day precision (relative standard deviation) were less than 10.23 and 13.09%, respectively. The developed method was applied for the first time to the pharmacokinetic study of teniposide in rats following a single intravenous administration of 4.5 mg/kg teniposide. Copyright © 2009 John Wiley & Sons, Ltd.     

Simultaneous determination of cyadox and its metabolites in plasma by high‐performance liquid chromatography tandem mass spectrometry

Cyadox is a novel antimicrobial growth‐promoter of the quinoxalines. For food safety and pharmacokinetic studies, a convenient, sensitive and reproducible LC‐ESI‐MS/MS method was developed for the simultaneous determination of cyadox and its major metabolites, quinoxaline‐2‐carboxylic acid, 1,4‐bisdesoxycyadox, cyadox‐1‐monoxide and cyadox‐4‐monoxide in chicken plasma. Plasma sample was subjected to a simple deproteinisation with acetonitrile. Analysis was performed on a C₁₈ column by detection with mass spectrometry in multiple reaction monitoring mode. A gradient elution program with 0.2% formic acid, methanol and acetonitrile was performed at a flow rate of 0.2 mL/min. The decision limits (CCαs) of five analytes in plasma ranged from 1.0 to 4.0 μg/L, and the detection capabilities (CCβs) were <10 μg/L. Acceptable precision and accuracy were obtained for concentrations over the standard curve range. The extraction recoveries of five analytes were between 87.4 and 93.9% in plasma at the spiked levels of 5 (10)–200 μg/L with the relative standard deviations <10% for each analyte. The developed method demonstrated a satisfactory applicability in real plasma samples.     

Quantification of pramipexole in human plasma by liquid chromatography tandem mass spectrometry using tamsulosin as internal standard

A high-performance liquid chromatography/electrospray ionization tandem mass spectrometry method was developed and validated for the quantification of pramipexole in human plasma. Following liquid-liquid extraction, the analytes were separated using an isocratic mobile phase on a reverse-phase column and analyzed by MS/MS in the multiple reaction monitoring mode using the respective [M + H](+) ions, m/z 212/152 for pramipexole and m/z 409/228 for the IS. The method exhibited a linear dynamic range of 200-8000 pg/mL for pramipexole in human plasma. The lower limit of quantification was 200 pg/mL with a relative standard deviation of less than 8%. Acceptable precision and accuracy were obtained for concentrations over the standard curve range. A run time of 3.5 min for each sample made it possible to analyze more than 200 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.     

LC-MS/MS内标法测定水产品中三聚氰胺残留量

建立了高效液相色谱-电喷雾串联质谱(LC-MS/MS)测定水产品中残留的三聚氰胺的方法.以13C,15N标记三聚氰胺为内标,样品经三氯乙酸溶液沉淀蛋白,提取目标分析物,经SCX-C18均匀混合填装的反相色谱柱分离,选择反应监测(SRM)正离子模式测定.LC-MS/MS的检测低限为10 μg/kg;在10.0～500 ng/mL时峰强度与质量浓度的线性关系良好(r>0.99).方法的平均回收率为78%～118%.     

高效液相色谱-电感耦合等离子体质谱法测定土壤和沉积物中Cr(Ⅲ)与Cr(Ⅵ)EI北大核心CSCD

Cr(III) and Cr(VI) were separated by high performance liquid chromatography by using EDTA-Naj as mobile phase. Oxygen was added to reduce the interference of40Ar12C on+52Cr in mass spectrometry. The results showed that the linear relationships of Cr(HI) and Cr(VI) were good in the concentration range of 0.5-100 μXg/L, and the correlation coefficients were 0.9997 and 0.9998, respectively. The method detection limits of Cr(TH) and Cr(VI) both were 0.1 μxg/L. The method was applied to determine standard substances of NSI Lab Solutions with three kinds of chromium speciation, and the results were agreement with the certified values. The recoveries were 91.9%-116.7% at three spiked concentrations. The method is suitable for the determination of water-soluble chromium in soil and sediment samples. © 2023, Youke Publishing Co.,Ltd. All rights reserved.     

Quantitative analysis and pharmacokinetics study of tigecycline in human serum using a validated sensitive liquid chromatography with tandem mass spectrometry method

Tigecycline, a novel intravenously administered glycylcycline antibiotic, currently plays a key role in the management of complicated multiorganism infections. However, current liquid chromatography with tandem mass spectrometry methods briefly describe parameters and the only reported internal standard was sometimes difficult to obtain. In our study, an updated liquid chromatography with tandem mass spectrometry method for the quantitative analysis of tigecycline in human serum was developed. Sample preparation involved precipitation with 20% trichloroacetic acid. Chromatographic separation of tigecycline and tetracycline (internal standard) was achieved on a Hypersil GOLD C₁₈ column using gradient elution. The selected reaction monitoring transitions were performed at m/z 586.1→513.2 for tigecycline and m/z 445.1→410.2 for tetracycline. The assay was linear over the concentration range of 5–2000 ng/mL. The intra‐ and interday precisions at three concentration levels (10, 100, and 1600 ng/mL) were <15% and their accuracies were within the range of 95.1–106.1%. The mean recovery ranged from 94.3 to 105.6% and the matrix effect from 92.1 to 97.6%. Tigecycline was stable under all tested conditions. This validated method was successfully applied to a pharmacokinetic study in critically ill patients. The data demonstrated that our method allows quantification of tigecycline in serum in a quick and reliable manner for widespread application.