Quantification of Teicoplanin in Human Plasma by Liquid Chromatography with Ultraviolet Detection

A simple high-performance liquid chromatographic method was developed for determining five major components of teicoplanin, designated A2–1, A2–2, A2–3, A2–4 and A2–5, in human plasma. Using piperacillin sodium as internal standard, teicoplanin in plasma samples was extracted by coextractive cleanup procedure. The extracts were injected into a Nova-Pak C₁₈ column maintained at ambient temperature. The mobile phase consisted of acetonitrile–0.1% trifluoroacetic acid (27:73, pH = 2.2), at a flow rate of 1.0 mL min⁻¹. The analytes were detected at the UV wavelength of 218 nm. The method was found to be linear over the concentration range of 2.5–50 mg L⁻¹ for teicoplanin (r = 0.9993 ± 0.0038), which covered the clinically expected trough plasma levels. The percentage error of the analytical method was below 9%. The intra- and inter-day reproducibility was adequate with coefficients of variation less than 7%. The chromatographic running time was 11 min. Thus, the method can be effectively applied to measure teicoplanin concentrations in clinical samples.     

Development and Validation of a Liquid Chromatographic Method for Determination of Efavirenz in Human Plasma

A simple, rapid, and sensitive high-performance liquid chromatographic method for estimation of efavirenz in human plasma has been developed and validated. Chromatography was performed with C₁₈ analytical column and 50:50 acetonitrile–phosphate buffer (pH 3.5) as mobile phase. Compounds were monitored by UV detection at 247 nm. The retention time for efavirenz was 6.45 min and that for the internal standard, nelfinavir, was 2.042 min. Response was a linear over the concentration range of 0.1 μg–10 μg mL⁻¹ in human plasma. The method was simple, specific, precise and accurate and was useful for bioequivalence and pharmacokinetic studies of efavirenz.     

高效液相色谱电化学法检测人体血浆中芹菜素和相关黄酮类化合物

建立了同时检测人体血浆中芹菜素等5种黄酮类化合物含量的反相高效液相色谱法。血浆样品经固相萃取柱提取后,用Hypersil C18色谱柱分离样品,流动相为甲醇/磷酸水溶液(V/V,2/3,pH2.25),等度洗脱,流量为1 mL/min,柱温为40℃,用电化学检测器在直接模式下,1100 mV分析检测待测物,内标法定量。对于全部待测组分r均大于0.99;槲皮素、毛地黄黄酮、山奈酚、芹菜素和异鼠李黄素线性范围分别为3~7000、3~5900、3~7000、5~7000和3~7400 nmol/L;检出限为1.4~4.8 nmol/L。方法的实际样品加标回收率为86.8%~102.9%;相对标准偏差(RSD)低于7.4%(n=3)。方法简便、快速、准确,可用于芹菜素等黄酮类化合物在人体内的生物利用度及膳食干预研究。     

高效液相色谱－电化学检测法同时测定血浆中5－羟色胺和5－羟吲哚乙酸

A simple and Sensitive method for the simultaneous measurement of serotonin(5-HT)and 5-hydroxyin-doleacetic acid(5-HIAA)in plasma is described.Plasma samples,only deproteinated,without further extraction,were directly injected into and high performance liquid chromatographic column and detected electrochemically. Within 18 min,the total separation was achieved.The recovery reached over 90%. The coefficient of variation inretention time was less than 2.5%and in peak area was less than 1.2%.     

反相高效液相色谱法测定人血浆中异丙酚浓度

用柱前衍生化反相高效液相色谱法测定人血浆中异丙酚浓度,为临床药理学研究提供了依据。提取的异丙酚及内标麝香草酚同时以Ｇｉｂｂｓ试剂衍生化,衍生物经色谱柱分离和紫外检测,异丙酚在５０～１５００μｇ／Ｌ浓度范围内呈线性关系（ｒ＝０．９９９１）。方法平均变异系数为６．１％,最低检出浓度为２４．８μｇ／Ｌ,已满意地用于临床药理学研究。     

Liquid Chromatographic Analysis of Cephalexin in Human Plasma by Fluorescence Detection of the 9-Fluorenylmethyl Chloroformate Derivative

Abstract

A simple and sensitive precolumn derivatization method for the determination of cephalexin in human plasma has been developed. Cephalexin was derived with 9-fluorenylmethyl chloroformate (FMOC-Cl) in borate buffer (5 mM, pH 8.5) for 15 min at 25°C. Optimal conditions for the derivatization were described. The derivative was chromatographed on an XDB-C₁₈ column with water–acetonitrile (10:90, v/v) as mobile phase at a flow rate of 1.0 mL/min. The fluorescence excitation and emission wavelengths were 268 nm and 314 nm, respectively. The standard curve in spiked plasma was linear over the range of 0.0234–58.5 µg/mL; the detection limit (signal-to-noise ratio = 3; injection volume, 10 µL) was about 0.014 µg/mL. The performance of analysis was studied, and the validated method showed excellent performance in terms of selectivity, sensitivity, precision, and accuracy.     

Simple High-Performance Liquid Chromatographic Assay, with Post-Column Derivatization, for Simultaneous Determination of Mycophenolic Acid and its Glucuronide Metabolite in Human Plasma and Urine

Two simple high-performance liquid chromatographic (HPLC) methods have been established for simultaneous determination of mycophenolic acid (MPA) and its glucuronide metabolite (MPAG) in human urine, and of their total and unbound forms in human plasma. For total MPA and MPAG analysis sample preparation entailed precipitation of protein with acetonitrile and isolation of the free analytes from the plasma by ultrafiltration. For urine samples, fivefold dilution with water was used. MPAG was determined by UV detection whereas MPA was quantified by fluorescence detection after post-column derivatization with 0.2 M sodium hydroxide solution. For plasma, response was found to be linearly dependent on concentration over the ranges 0.1–40 μg mL^-1 and 0.01–1 μg mL^-1 for total and free MPA, respectively, and 10–200 μg mL^-1 and 2.5–100 μg mL^-1 for total and free MPAG, respectively. For urine, linearity was observed from 0.1 to 50 μg mL^-1 for MPA and 10 to 500 μg mL^-1 MPAG in the urine before dilution. The methods reported were found to be accurate and reproducible for quantifying the level of MPA and MPAG and can thus be used for clinical pharmacokinetic studies and for therapeutic drug monitoring. Contributed equally to this work An erratum to this article is available at .     

高效液相色谱－荧光检测法测定人血浆中匹伐他汀的含量

 Pitavastatin belongs to the class of coenzyme A reductase inhibitors. Very few methods of assaying pitavastatin from human plasma are available in literature. An analytical method is presented for the determination of the drug from human plasma making use of the fluorescent property of the drug. The drug is extracted from plasma using ethyl acetate under neutral condition and then analyzed by reversed-phase high performance liquid chromatography (HPLC) with fluorescence detection (λEx 245 nm; λEm 420 nm). Analysis of pitavastatin was carried out on a C18 HPLC column using a gradient flow of mobile phase (0.01 mol/L monobasic potassium phosphate (pH 3.20)-acetonitrile, 63∶37, v/v). Fluorescein isothiocyanate was used as internal standard. The dynamic range of assay was 3 to 50 ng/mL. The intraday precision was less than 10% and accuracy ranged from 95.2% to 112.6%. The same for interday check was less than 12% and 92.8% to 105.1%, respectively. The drug was found to be stable under the assay conditions. The developed method is simple, precise, accurate, and stable. This indicates that it can be applied to routine analysis of this drug in human subjects where there are large numbers of samples without the need of specialized instruments like column switching.     

Commercial Screen‐Printed Gold Electrodes for the Detection and Quantification of Aminothiols in Human Plasma by Liquid Chromatography with Electrochemical Detection

In order to show the possibilities of screen‐printed electrodes in HPLC detection, a method is presented for routine quantification of aminothiols in human plasma. It uses commercial gold screen‐printed electrodes and provides a rapid, simple and economical procedure with a disposable detector and without any additional electrode. By working at 98 : 2 (0.05 % trifluoroacetic acid: methanol) and 0.9 V, it allows us to determine cysteine (Cys), cysteinyl‐glycine (Cys‐Gly), and homocysteine (HCys) at μmol/L levels. The method was validated, and linearity range, detection and quantification limits, precision and accuracy were evaluated by external calibration and by using N‐acetylcysteine as internal standard, which exhibited better precision.     

胶束电动毛细管色谱分析间接紫外吸收检测人体血小板活化因子

研究了人体血小板活化因子中1-O-十六烷基乙酰甘油磷酰胆碱与1-O-八烷基乙酰甘油磷酰胆碱的胶束电动毛细管色谱分离条件与间接紫外吸收检测条件。首次采用高效毛细管电泳法成功地分析了人体血小板活化因子中两种主要磷酰胆碱的含量。     

高效液相色谱法测定血中苯妥英浓度

A high performance liquid chromatographic method for the quantitative analysis of phenytoin(PHT) inhuman plasma or whole blood is described. After a onestep extraction of PHT and internal standard withethyl acetate from human plasma or whole blood,samples were chromatographed on a Spherisorb-C(18) columnwith a mobile phase of methanol-water-tetrahydrofuran(45/55/5,V/V/V)at a flow rate of 0. 3mL/min. Theeluant was monitored at 210nm.     

A Rapid Liquid Chromatographic Method for Determination of Flecainide in Human Blood Plasma Using Ultraviolet Detection

Abstract

A liquid chromatographic method for the assay of the antiarrhythmic drug flecainide in plasma has been developed. The method is rapid, simple and with sufficient detection sensitivity to render it suitable for therapeutic drug monitoring. Flecainide and added internal standard, a non-fluorinated analogue, were extracted by a single ether extraction from alkalinized plasma followed by a back-extraction of the ether with dilute phosphoric acid. A portion of the acid extract was then applied directly to a 30 cm ODS column eluting isocratically with 30% acetonitrile in water containing 0.01M dibutylamine phosphate. Monitoring was by ultraviolet detection at 214 nm and the total run time was 8 min. This method is specific and can quantitate plasma levels to less than 30 ng/ml (free base) from 0.5 ml of plasma without interference from antiarrhythmic drugs commonly used in therapy.     

高效液相色谱法测定鸡肝中玉米赤霉醇的残留量

建立了高效液相色谱测定鸡肝中玉米赤霉醇的方法。样品经β-葡糖苷酸酶水解、乙醚提取、氢氧化钠抽提、C18小柱净化后,用Zorbax SB-Phenyl柱(250 mmx4.6 mm i.d., 5 μm)分离,以乙腈-0.3%三氟乙酸水溶液(体积比为40∶60)作流动相,流速为0.80 mL/min,于262 nm波长处检测。结果表明,样品的加标平均回收率为72.0%-80.4%,相对标准偏差为8.3%-13.9%,定量测定低限(LOQ)为5 μg/kg。方法已应用于实际样品的测定。另外,用高效液相色谱-质     

Improved High Pressure Liquid Chromatographic Method for Phenylpropanolamine in Human Plasma

Abstract

A high-pressure liquid chromatographic analysis of phenylpropanolamine in plasma following extraction, back extraction and pre-column derivitization with O-phthalaldehyde is presented. The method is improved by the use of phenylethanolamine as internal standard. Using fluorescence detection, the method is sufficiently sensitive to quantitate 5 ng/ml in 0.5 ml plasma with a standard error of estimate of 2.7 ng/ml when calibrated over the O to 240 ng/ml range. Analysis of over 2000 clinical samples have shown the method to be highly specific and reliable.     

柱切换-荧光检测反相高效液相色谱法测定血浆中特布他林浓度

采用柱切换技术 荧光检测反相高效液相色谱法测定血浆中特布他林 (TB)浓度。使用LunaC8( 2 )和KromasilC18为分析柱 ( 1 5 0mm× 4.6mm ,5 μm)和预处理柱 ( 2 5mm× 4.6mm ,5 μm) ,流动相分别为pH 3 0 ,0 .0 3 3mol/L磷酸盐缓冲液∶甲醇∶乙腈 ( 92∶7∶1 )和水∶甲醇∶乙腈 ( 97∶2∶1 ) ,流速均为 1 .0ml/L。血浆样品经乙腈沉淀蛋白后进样 ,切换时间为 3 .2～ 4.2min。荧光检测 ,λex为 2 80nm ,λem为 3 0 9nm。以沙丁胺醇作内标 ,按内标法定量。标准曲线线性范围为 0 .8～ 3 2 μg/L ;最低定量限为 0 .8μg/L;TB和内标的保留时间分别为 8.7和 9.3min;日内RSD小于 4% ,日间RSD小于 9% ,方法回收率在 93 %～ 1 1 2 %。     

High-Performance Liquid Chromatographic Determination of Isofraxidin in Rat Plasma

For the first time a high-performance liquid chromatographic (HPLC) method, with liquid-liquid extraction and ultraviolet (UV) absorbance detection, has been developed for quantification of isofraxidin in rat plasma. The analysis was performed on a Diamonsil C₁₈ column (200 mm × 4.6 mm i.d., 5 μm particle size) with acetonitrile–0.05% phosphoric acid, 26:74 (v/v), as isocratic mobile phase. The linear range was 0.05–8.0 μg mL⁻¹ and the lower limit of quantification was 0.05 μg mL⁻¹. The intra and inter-day relative standard deviation (RSD) for measurement of 0.25, 2.0, and 6.0 μg mL⁻¹ quality-control (QC) samples ranged from 5.7 to 6.4% and from 6.3 to 7.9%, respectively. Accuracy, as relative error (RE), was from ±5.8% to ±7.3%. The method was validated for specificity, accuracy, and precision and was successfully used in a pharmacokinetic study of isofraxidin in rat plasma after administration of Ciwujia extract.     

高效液相色谱-紫外检测法测定人体尿液中的蝶呤-6-羧酸

建立了人体尿液中蝶呤-6-羧酸的高效液相色谱-紫外分析新方法. 运用Lichrospher C18柱(250×4.6 mm,5 μm),甲醇-水(70∶30,V/V)为流动相,流速为0.4 mL/min,可较好地将尿液中蝶呤-6-羧酸与其它共存干扰物质分离.在355 nm检测波长下,蝶呤-6-羧酸在0.19～4.8 μg/mL范围内与色谱峰面积呈良好线性关系,相关系数为0.9999,方法检出限为0.015 μg/mL.尿液经0.45 μm滤膜过滤后,可直接进样分析,方法简便,应用于癌症病人和健康人尿样中蝶呤-6-羧酸测定,结果较好.方法的加标回收率为94.6%～100.2%,相对标准偏差为0.81%～ 5.07% .     

高效液相色谱/荧光检测法同时测定高分子材料中6种异氰酸酯

建立了高分子材料中6种异氰酸酯含量的高效液相色谱/荧光检测法。样品中的异氰酸酯经萃取衍生,C18色谱柱梯度洗脱分离后,以荧光检测器检测,外标法定量。考察了萃取剂、萃取方式、衍生化时间及流动相组成对异氰酸酯萃取量、衍生化效果及分离效果的影响。结果表明,选用极性萃取剂二氯甲烷超声萃取的回收率高于非极性萃取剂环己烷振荡萃取的回收率,最佳衍生化时间为30 min。流动相采用乙腈-三乙胺缓冲液梯度洗脱时,目标组分的分离度高于1.5,在10~100 μg/L范围内异氰酸酯衍生物的线性相关系数不低于0.999 1。高分子样品中异氰酸酯的加标量在0.1~1.0 mg/kg范围内,平均回收率为90%~95%,相对标准偏差(RSD,n=5)为2.2%~4.2%。检出限(信噪比为3)为30.3 ~42.3 μg/kg。实际样品检测结果表明,除苯基异氰酸酯(PI)外的5种异氰酸酯在样品中均有不同程度检出,总含量为79.7~326.3 μg/kg。该方法准确、灵敏、重现性好,适用于高分子材料中异氰酸酯残留量的检测。     

高效液相色谱法（荧光检测）分析人血浆中哌啶酸

本工作用丹磺酰氯柱前衍生比反相色谱（荧光检测）法分析了正常人和肝病患者血浆中哌啶酸－２的水平。样品用荧光胺提取法,除去血浆中的其他氨基酸和生物胺对检测的干扰。以哌啶酸－３为内标物,测得平均回收率为８４％。至少在４０ｐｍｏｌ至２ｎｍｏｌ范围内,浓度与响应的线性关系良好。两个哌啶酸的检测极限分别为２．０和２．５ｐｍｏｌ。对操作中应予注意的几个步骤作了讨论。     

固相萃取-高效液相色谱法测定人血浆中的川芎嗪

建立了高效液相色谱测定人血浆中川芎嗪浓度的方法。色谱条件:分析柱为Luna C18(150 mm×4.6 mm i.d.,5 μ m),流动相为甲醇-乙腈-醋酸盐缓冲液(pH 5.0)(体积比为50∶8∶42),流速1.0 mL/min,柱温40 ℃,检测波长280 nm。 血浆样品预处理采用C8固相小柱萃取法。方法的线性范围为25～5000 μg/L,线性相关系数为0.9999。高、中、低浓度 的川芎嗪在标准血浆样品中的平均提取回收率为96.72％～100.90％,日内和日间相对标准偏差(RSD)小于8.64％,准确度 为99.59%~103.26%,检测限为10 μg/L。该方法的各项效能指标符合生物样品的分析要求,可用于川芎嗪制剂的人体药 代动力学研究。