Assay of Brain Tocopherols Using High Performance Liquid Chromatography

Abstract

The four natural tocopherols were separated using a μ-Bondapak-NH₂ column. For the analysis of brain tocopherols 5,7-dimethyltocol was used as an internal standard. α-Tocopherylquinone and other tocopherols than α-tocopherol were not detected. Rat cerebral cortex and cerebellum contained 19.3 μmol/g and 11.2 μmol/g of α-tocopherol, respectively. A chromatographic system with a reversed-phase column proved less suitable.     

Assay of Yohimbine in Human Plasma Using High Performance Liquid Chromatography with Electrochemical Detection

Abstract

Yohimbine is a selective α₂ adrenoreceptor antagonist used in the study of α₂ adrenoreceptors in man. In order to better improve administration regimens for the study of yohimbine in man, we have developed an assay for the determination of yohimbine in plasma utilizing reverse phase high performance liquid chromatography with electrochemical detection. Using a C₁₈ column and a methanol:acetate (60:40) mobile phase, we detected yohimbine in plasma following a simple chloroform extraction. Reserpiline was used as an internal standard. The assay was linear over a concentration range of 50–250 ng/ml in spiked plasma and had a lower limit of sensitivity of 10 ng/ml. It was used to detect yohimbine in plasma sampled from 4 volunteers during an infusion of the alkaloid.     

A Rapid Quantitative Assay of Sparsomycin by High Pressure Liquid Chromatography

Abstract

Fast quantitative analysis of sparsomycin in fermentation broth can be accurately carried out by Amberlite XAD-2 column chromatography followed by normal phase high pressure liquid chromatography using a Porasil T column (2mm ID × 61 cm) and a mobile phase consisting of ethyl acetate-methanol-concentrated ammonium hydroxide (90:10:0.1).     

High Performance Liquid Chromatography Assay of Itraconazole in Human Plasma

Abstract

A high performance chromatographic method, using internal standard quantification, for the analysis of Itraconazole in human plasma is described. The standard curve was linear over the concentration range tested. The detection limit of the method was 250 ng. An authentic sample of both Itraconazole and the internal standard (ketoconazole) were used to establish the calibration curve.     

用高效液相色谱法快速测定甜菊糖甙

本文介绍了用高效液相色谱法分离测定甜菊糖甙的四种成分,测定了各成分的相对百分含量及甜菊饮料制品中各糖甙成分及糖类的含量,并做了精密度和回收率的验证。该法简便快速,效果良好。色谱条件为:μ-Bondapak NH_2往,柱前加Bondapak AX/Corasil预柱;乙腈:0.02M(NH_4))2 HPO_4水溶液=75:25作流动相,流速为2.0ml·min~(-1);示差折光检测。     

Assay of Arginine-Esterase Activities by Reversed Phase High Performance Liquid Chromatography

Abstract

Application of a high performance liquid chromato-graphic technique to assay of arginine-esterase activities is presented. Enzyme reaction was carried out with benzoyl-L-arginine ethylester as a substrate and analysis was performed on a reversed phase chromato-graphic system using a μ Bondapak C₁₈ or a Radial-PAK A column and buffered aqueous methanol as the mobile phase. The enzyme activities were determined by the peak height of cleaved product (benzoyl-L-arginine). The minimum detection limit for benzoyl-L-arginine was 0.02 nM on each column. The generality of this method was demonstrated by its application to determination of plasmin activity, and so it might be suitable for both kinetic studies and routine assays of plasmin-like es-terases.     

高效液相色谱对液态奶中三聚氰胺的快速测定

建立了有机溶剂提取和离子对色谱相结合的三聚氰胺快速检测方法.样品中加入有机溶剂振荡提取,取上清液过滤进行高效液相色谱(HPLC)分析.对丙酮、乙腈、乙醇和异丙醇的提取物分别在甲醇-离子对试剂流动相体系和乙腈-离子对试剂流动相体系中进行测定和比较.结果显示,选择合适的流动相,使用丙酮、乙醇或异丙醇为提取剂可以获得较好的提取效果.在甲醇-离子对试剂流动相体系中,三聚氰胺的质量浓度在1.0 ～100.0 mg/L范围内与色谱峰面积呈良好的线性关系(r=0.999 98),检出限为0.1 mg/kg,采用丙酮为提取剂,加标回收率为97% ～103%,相对标准偏差(RSD)小于5%.     

高效液相色谱法测定复方芦丁片中芦丁和维生素C的含量

采用反相高效液相离子对色谱法,以对氨基苯甲酸为内标,测定了复方芦丁片中芦丁和维生素Ｃ的含量。色谱柱为μ－ＢｏｎｄａｐａｋＣ_（１８）,流动相为甲醇－水（５０：５０）配制的樟脑磺酸溶液（０．００２５ｍｏｌ／Ｌ）,检测波长为２５４ｎｍ。并做了线性范围和回收率测定。     

高效液相色谱/氢化物发生/原子荧光快速检测尿砷形态

本文对砷形态分析方法进行了评述。提出了人尿中Ａｓ（Ⅲ）、Ａｓ（Ⅴ）、一甲基砷（ＭＭＡ）和二甲基砷（ＤＭＡ）的快速、灵敏的形态分析方法。方法基于在１５ｃｍ长、３μｍ粒径的ＨＰＬＣ柱上快速分离不同形态的砷后以灵敏的氢化物发生／原子荧光检测。常见砷的四种形态的分析只须４ｍｉｎ即可完成,检出限在μｇ／Ｌ级。标准样品尿中砷的形态分析结果与标准值吻合很好。本法已应用于摄取砷糖前、后所采集的尿样中砷的形态分析研     

Determination of Some Penicillin Derivativies Using High Performance Liquid Chromatography

Abstract

A rapid, precise and selective method is described for determination of penicillin derivatives. Penicillin derivatives are separated from closely related degradation products by high performance liquid chromatography at ambient temperature using 10cm column packed with 5um Nucleosil RP₁₈ and buffered aqueous acetonitrile as mobile phase. The eluate is monitored at 254nm. The procedure is suitable for determination of 8 penicillin derivatives either in raw material or phamaceutical dosage forms.     

高效液相色谱法快速测定鸡蛋中5种氟喹诺酮类药物残留

建立了一种检测鸡蛋中环丙沙星、达氟沙星、恩诺沙星、二氟沙星及沙拉沙星残留的高效液相色谱方法。该方法前处理简便快速,样品经低浓度乙腈结合加热促使蛋白质快速沉淀,正己烷脱脂,分离清液后进高效液相色谱仪分析。流动相为0.05 mol/L磷酸/三乙胺溶液-乙腈溶液(80∶20),荧光检测器的激发波长为280 nm,发射波长为450 nm。该方法对环丙沙星和二氟沙星的定量下限为5μg/kg,达氟沙星的定量下限为0.5μg/kg,恩诺沙星的定量下限为2.5μg/kg,沙拉沙星的定量下限为10μg/kg。在定量下限及低、中、高4种加标浓度下,5种氟喹诺酮类药物的平均回收率为92.2%~107.1%,批内相对标准偏差(RSD)为0.6%~5.8%,批间相对标准偏差为1.5%~5.0%。方法具有前处理简单、环保、快捷、准确度和灵敏度高等优点,适合生产线和流通环节鸡蛋样品的快速检测。     

反相高效液相色谱法快速测定7种四环素类抗生素

建立了一种反相高效液相色谱梯度洗脱分离测定四环素类药物的新方法。采用DiamonsilTM C1 8ODS(2 5 0mm× 4 .6mmi.d ,5 μm)色谱柱 ,以甲醇 乙腈 0 .0 1mol/L草酸为流动相 ,流速 1.0mL/min ,2 70nm检测 ,在10min内分离检测四环素等 7种化合物。同时还研究了流动相组成、梯度条件、pH值、草酸浓度等因素对分离效果的影响。     

Rapid Determination of Bupropion in Human Plasma by High Performance Liquid Chromatography

Abstract

A high performance liquid chromatographic (HPLC) technique has been developed for the determination of bupropion hydrocloride (Bup) in human plasma, using a reversed-phase method, with UV detection at 250 nm.

The internal standard 5-(P-methylphenyl)-5-phenylhydantoin (MPPH), was used as an aid to quantitation. The plasma was deprotemized with acetonitrile and the clear supernatant was directly injected in the chromatographic system. The lower limit of quantitation was 5.0 ng/ml using only 100 μl of plasma sample.

Linear regression analysis for the calibration plots obtained on five different days over a two-week period for the the two ranges used (10–250 ng/ml and 250–2000 ng/ml) in plasma indicated excellent linearity and reproducibility. The mean recovery of spiked Bup in plasma samples over the concentrations studied was found 96.5 ± 3.14%.

The method revealed that more than 30% of Bup was lost when the supernatant was stored at room temperature for 24 hrs.     

A New Assay for Argininosuccinate in Urine Samples by High Performance Liquid Chromatography

Abstract

A rapid, sensitive and simple procedure has been developed for determination of argininosuccinate (ASA). The assay is based upon the enzymatic cleavage of ASA in the presence of excess of argininosuccinate lyase (ASAL), HPLC separation and UV-detection of fumarate formed. The calibration curve, obtained using standards, derives from a linear correlation between the reaction rate and ASA concentration. The range of HPLC detection corresponds with the level of normal excretion of argininosuccinate in urine from the patients with argininosuccinate lyase deficiency (ASLD).     

Rapid Determination of Teicoplanin in Human Plasma by High Performance Liquid Chromatography

Abstract

A rapid isocratic reversed-phase HPLC method for the determination of the major component of teicoplanin in plasma is described.

By using solid phase extraction C18 and UV detection at 240 nm, this method is specific, and sufficiently sensitive.

We found a good linearity over the range: 5 – 40 mg/1 of teicoplanin plasma concentrations. The coefficients of variation did not exceed 5.4% both within-day and between-day assays.

With the small plasma sample required for the analysis (250 μl) and the good accuracy, this rapid procedure appears to be suitable for the therapeutic drug monitoring.     

High Performance Liquid Chromatography of Dithiolthiones

Abstract

Sixteen dithiolthiones including oltipraz (5-(2-Pyrazinyl)-4-methyl-1-1, 2 dithiol-3-thione) and anethol dithiolthione (P-methoxyphenyl-1,2-dithiol-3-thione) have been studied using an isocratic high performance liquid chromatographic system. The retention characteristics of these compounds were determined using a conventional C 18 reverse phase column and a μ Bondapack phenyl column. The mobile phases used consisted of several concentrations of methanol and water. All compounds studied were adequately detected in the nanogram range (30–100 ng on column) using ultra violet detection (UV) set at 300 nm. Several analogs and isomers were separated. The retention characteristics of the 16 compounds studied are reported for both columns using 4 mobile phases and chromatograms of reference standards are presented.     

反相高效液相色谱法分离测定烟草中的多酚类化合物

对植物中9种多酚类化合物的色谱分离条件进行了优化,分别探讨了流动相组成、流动相中醋酸浓度、醋酸溶液与甲醇的比例对保留时间的影响,确定了梯度分离条件,并对9种天然多酚类化合物进行了定量分析。该方法的检测限为13.26~59.29 mg/kg (S/N=3)。在3.0～100.0 mg/L 范围内呈良好的线性关系,相关系数r2为 0.9979~0.9999。9种待测化合物的加标回收率为96.8%~108%,相对标准偏差(RSD)小于3.8% (n=3)。用80%甲醇超声提取烟草样品,并通过优化的色谱条件对其进行分析,测定了实际烟草样品中芸香苷和绿原酸的含量。结果表明,该方法具有一定的实用价值。     

猪肉中二甲胺四环素的反相-高效液相色谱测定

建立了一种测定猪肉中二甲胺四环素的反相-高效液相色谱(RP-HPLC)分析方法.目标物经EDTA-Mcllvaine提取,用Oasis HLB固相萃取小柱净化,流动相为甲醇-咪唑缓冲溶液,体积比20:80,荧光检测器检测,外标法定量.平均添加回收率在89.6％～94.0％之间,相对标准偏差(RSD)在3.1％～6.5％...     

Assay of Erythromycin from Human Serum by High Performance Liquid Chromatography with Electrochemical Detection

Abstract

A sensitive and selective method has been developed for the determination of serum concentrations of erythromycin A by high performance liquid chromatography with electrochemical detection. Erythromycin was extracted from alkalinized serum samples with methyl t-butyl ether. After evaporation of the ether, the samples were reconstituted in acetonitrile/ammonium acetate and washed with hexane. Aliquots were injected onto a Sepralyte diphenyl column. The mobile phase consists of acetonitrile/sodium perchlorate/ammonium acetate/methanol under isocratic conditions. Eluted peaks were detected by dual coulometric electrodes operated in the oxidative screen mode. The recovery of erythromycin from serum was 84%. Assay limit of quantification was 0.05 μg/ml serum, and dynamic linear range was 0.05–1.5 μg/ml. This method was used to quantitate both erythromycin and its gastric degradation products from human serum. Additionally, other macrolide antibiotics could be quantified by electrochemical detection. Analytical results for erythromycin compared favorably with those obtained with a standard microbiological assay.     

全自动免疫亲和在线净化/高效液相色谱法快速高通量测定饲料中黄曲霉毒素

建立了全自动免疫亲和在线净化/高效液相色谱快速高通量测定饲料中黄曲霉毒素(Aflatoxins,AFT)的分析方法。饲料样品经乙腈-水(80∶20,体积比)提取,3 g/L Triton X-100水溶液10倍稀释后,用自动进样器注入RIDACREST在线固相萃取系统并流经黄曲霉毒素免疫亲和小柱,以甲醇-水(45∶55,体积比)为流动相,流速为1.0 m L/min,C18色谱柱(150 mm×3.5 mm,5μm)分离,光化学衍生,荧光检测器测定。根据3倍信噪比的峰响应值,确定黄曲霉毒素B1,B2,G1,G2的检出限分别为0.08,0.05,0.18,0.08μg/kg,分别在1~100,0.24~24,0.56~56,0.24~24μg/kg范围内呈线性相关,相关系数(r2)分别为0.999 4,0.999 7,0.999 8和0.999 8;AFT在猪饲料、鸡饲料、宠物饲料和饲料原料4类样品中的加标回收率为72.6%~103%,相对标准偏差为2.5%~4.9%。该方法一次装柱可检测60个样品,液相色谱分析一个样品总的运行时间为15 min,所以1 d可检测70~80个样品,满足饲料中黄曲霉毒素快速高通量准确定量检测的需要。