Determination of Chlordiazepoxide and Its Metabolites in Plasma by High Pressure Liquid Chromatography

Abstract

A rapid, sensitive and specific high pressure liquid chromatographic (HPLC) assay was developed for the determination of chlordiazepoxide and its metabolites from plasma. The assay involves extraction of chlordiazepoxide and its metabolites into diethyl ether from plasma buffered to pH 9. The overall recovery of chlordiazepoxide is 80 ± 5.0% (S.D.) and the sensitivity limit of detection is 50 to 100 ng/ml of plasma, using a 1 ml specimen. The assay was used in the determination of plasma levels of chlordiazepoxide and its metabolites in man following oral administration of chlordiazepoxide. HCl.

The chromatographic behavior of other clinically important benzodiazepines and their major metabolites is also reported.     

Determination Of Chlorpromazine And Its Sulfoxide And 7-Hydroxy Metabolites By Ion-Pair High Pressure Liquid Chromatography

Abstract

An ion-pair HPLC approach with ordinary silica has been applied, with detection by ultraviolet absorption, to the assay of plasma for chlorpromazine and its sulfoxide on the one hand, and for 7-hydroxychlorpromazine (an active metabolite) on the other hand. The respective sample-preparation procedures entail extraction of the plasma with heptane at strongly alkaline pH, or else with diethyl ether at a less alkaline pH and with ensuing back-extraction and re-extraction. For each of the compounds, levels as low as 10 ng. ml^?1 are measurable. The conditions adopted are such that specificity and reproducibility are satisfactory although chlorpromazine and its various metabolites, especially 7-hydroxychlorpromazine, are chemically unstable and, moreover, are readily lost onto glass. With the unorthodox separation system adopted, adsorption rather than partition appears to be the dominant mechanism.     

液相色谱法检测水产品中亚甲蓝及其代谢物残留

建立了液相色谱同时检测水产品中亚甲基蓝及其代谢物天青A、天青B、天青C残留的方法并用于样品检测.试样中残留的药物以含离子对试剂对甲苯磺酸的乙酸铵缓冲液-乙腈提取,二氯甲烷反萃,MCAX固相萃取小柱净化,液相色谱测定.对提取、净化及仪器分离分析条件进行了探讨,对亚甲基蓝在分析过程的稳定性进行了研究.水产品中4种化合物在0.005～0.50 mg/kg范围内线性关系良好,相关系数为0 9946～0.9978.在0.005～0.5 mg/kg浓度范围内,平均加标回收率为75.9%～93.2%; 相对标准偏差为3 3%～11.9%; AZA、AZB、AZC、MB的检出限分别为1.27、0.98、1.48和1.33μg/kg.方法稳定可靠,可满足水产品中亚甲基蓝及其代谢物的检测需要.     

Determination of Amikacin Isomers by High Pressure Liquid Chromatography

Abstract

A high-pressure liquid chromatographic (HPLC) method for quantitative monitoring of amikacin isomers is described. Four isomers, BB-K8, BB-K29, BB-K6 and BB-K11 were applied to a silica gel column. While adsorbed, the isomers were derivatized with o-phthalaldehyde and the derivatized products eluted with ethanol. A decrease in the fluorescence of the derivatized products with time was observed. Heating at 50°C for 5 min produced products with stable fluorescence for at least three hours. Using the fluorescent properties of the amikacin derivative for detection, the four isomers of amikacin were separated by reverse phase (HPLC). A linear relationship from 1 to 10 μg/mL was obtained for all four isomers.     

痕量神经肽的高效液相色谱

本文选用芴甲氧羰基氯(FMOC-CL)作为肽的荧光衍生试剂,建立了两段淋洗分离测定神经肽RP-HPLC的方法。衍生反应简便、快速、衍生物稳定。FMOC-脑啡肽、FMOC-P物质在18min内全部被洗脱。本方法在1～100pmol具有良好的定量线性关系。当信噪比为2.5:1时,检测极限:FMOC-甲硫脑啡肽为405fmol,FMOC-亮脑啡肽337fmol,FMOC-P物质为500fmol。并且能够容易地脱去衍生基团得到反应前的神经肽。     

Determination of Pentachlorophenol Laurate by High Pressure Liquid Chromatography

Abstract

Pentachlorophenol Laurate (PCPL) in canvas is determined by extraction and chromotography on silica gel. Conditions are chosen to eliminate peak splitting due to the presence of different “laurate” fatty acids. The determination is faster and more specific than previously reported methods.     

Paired-Ion High Pressure Liquid Chromatography of Methotrexate and Metabolites in Biological Fluids

Abstract

A paired-ion high pressure liquid chromatography procedure (HPLC) is described for the separation of methotrexate and its major metabolites (7-hydroxymethotrexate, 4-amino-4-deoxy-N^lO-methylpteroic acid, methotrexate diglutamate, methotrexate triglutamate), and therapy-related compounds (Diamox and 5-methyltetrahydrofolate). The mobile phase consisted of a 70% solution of 5 mM hexanesulfonic acid, pH 3.75, and 30% methanol eluted on a reverse phase column or columns and monitored at 305 nm or 280 nm UV absorption. The lower limit of sensitivity for methotrexate and 7-hydroxymethotrexate in plasma was 2 ng/ml.     

High Performance Liquid Chromatography Determination of Chlorpropham and Its Metabolites in Isolated Rat Hepatocyte Incubations

Abstract

Free chlorpropham (CIPC) and its metabolites (4-hydroxy CIPC, 3-chloroani-line and 3-chloroacetanilide) were separated by reverse phase high performance liquid chromatography (H.P.L.C.) using an isocratic procedure. The separation was used to quantify the metabolism of CIPC in rat hepatocyte incubations. The free metabolites were diethylether-extracted at pH 7.4. The sulfate and glucuronide conjugates of 4(OH)CIPC were enzymatically split and the aglycone determined by HPLC. Beside the unmetabolized CIPC which accounts for 33% of the dose, 4(OH)CIPC as the sulfoconjugate and glucuroconjugate represents 35% and 20% respectively, while free 4(OH)CIPC accounts for only 3%. About 10% of the CIPC is hydrolytically split yielding 3-chloroaniline (2%) which further transformed into 3-chloroacetanilide (5%).

In spite of the great sensitivity of the proposed method (0.2 μg/ml incubation medium) no other metabolites were recorded. This extraction and separation procedure could be applicable to future metabolic studies in cellular incubation systems.     

Urinary Uric Acid Determination by Reversed-Phase High Pressure Liquid Chromatography

Abstract

Reversed-phase high pressure liquid chromatography with UV detection was proven to be a powerful method for the separation and quantitation of urinary uric acid. We have compared three different treatments for urine samples previous chromatographic injection: alkaline methanol extraction, ethylacetate extraction and centrifugation. It was also studied storage conditions for urine samples.

Our findings show that the method has high specificity and reproducibility for urinary uric acid. Samples are stables and require only centrifugation previous injection to the chromatograph.     

氰氟草酯及其代谢物在稻田水、土壤和稻株中的残留分析方法

研究并建立了氰氟草酯及其 4种代谢物在稻田水、土壤及稻株中的残留分析方法。在同一色谱分析条件下 ,同时检测 5种化合物 ,样品前处理过程简单 ,方法准确可靠 ,灵敏度和准确度达到了农药残留检测的要求。氰氟草酯及 4种代谢物在上述样品中的最低检知浓度在 0 .0 2～ 0 .0 0 4mg kg之间 ,方法的添加回收率(0 .0 1～ 5mg kg)在 80 .2 %～ 1 0 1 .2 %之间     

高效液相色谱法测定脂肪中11种苯并咪唑类药物残留标志物

建立了同时测定脂肪中11种苯并咪唑类药物残留标志物的高效液相色谱法。样品采用正己烷溶解后,加入抗氧化剂,用0.1 mol/L盐酸-乙腈(1∶1,体积比)提取,经正己烷脱脂后再次加入抗氧化剂,以MCX固相萃取柱净化。净化液浓缩处理后进行高效液相色谱分离,以甲醇-1%乙酸为流动相梯度洗脱,流速为1.0 mL/min,紫外检测波长为292 nm,采用外标法以峰面积定量检测。11种目标物均在25.0～1 000μg/L范围内线性良好,方法定量下限为50μg/kg,在3个加标水平下的回收率为82.0%～109%,相对标准偏差(RSD)为0.71%～9.9%。该方法能够满足脂肪中苯并咪唑类药物残留标志物的检测要求。     

Determination of Sterigmatocystin in Fungal Cultures by High Pressure Liquid Chromatography

Abstract

Levels of sterigmatocystin in cultures of various fungal strains were determined by high pressure liquid chromatography (HPLC). This mycotoxin was well separated using acetonitrile / water / acetic acid (55/45/2) as solvent on a μ-Bondapak C18 column (Waters Associates). It was detected by its absorbance at 320 nm. Using this method, sterigmatocystin can thus be simply and rapidly determined in mould strain cultures.     

Quantitative Determination of Polypeptides by Gradient Elution High Pressure Liquid Chromatography

Abstract

High pressure liquid chromatographic (HPLC) methods are described for the quantitative determination of polypeptides in pharmaceutical dosage forms or in synthetic and natural products.

Owing to the addition of an electrolyte for the inactivation of the residual silanol groups present on the modified silica surface, hydrophobic stationary phases were found which proved to be very suitable for the analyses of polypeptides.

Excellent results were obtained with tetramethyl-ammonium containing buffer systems at pH 3 in a gradient of water-methanol. Thus the polypeptides arginine-, lysine vasopressin, oxytocin, ACTH (1–24), ACTH, β-endorphin, glucagon and porcine- and bovine Insulin could be determined with coefficients of variation below 2%.     

高效液相色谱法测定粮食中玉米赤霉烯酮及其代谢物

采用甲醇-水提取,C18小柱净化,反相HPLC荧光检测器测定了玉米、面粉、小麦样品中的玉米赤霉烯酮及其代谢物和黄曲霉B1。对样品预处理和高效液相色谱测定条件进行了优化,ZON,α-ZOL,β-ZOL和AFTB1的线性范围分别为5.0μg/L~146g/L,25.0μg/L~200g/L,25.0μg/L~160g/L和0.4μg/L~2.0g/L,检出限分别为0.5、2.5、2.5和0.04μg/kg;加标回收率在80.0%~110.0%范围内;日间相对标准偏差为4·5%~9.2%,日内精密度2.7%~7.4%。本方法灵敏准确,易于推广,适用于粮食中玉米赤霉烯酮及其代谢物的检测。     

High Performance Liquid Chromatography—Tandem Mass Spectrometric Determination of Resveratrol and Its Metabolites in Rat Tissues

In this study, we established a rapid, sensitive, and specific liquid chromatography method coupled with electrospray ionization–tandem mass spectrometry to evaluate the disposition of resveratrol and its metabolites in rat tissues following oral administration. Here, we validate this method and show that it is useful for quantifying tissue concentrations of resveratrol and its metabolites with acceptable specificity, linearity, lower limits of quantification, precision, accuracy, and recovery. The present study demonstrates that the major distribution of the trans-resveratrol and its metabolites in investigated tissues, which suggests that there is a specified range of target organs for cancer chemoprevention by polyphenols.     

Determination of Bicascarosides in Cascara Fluid Extract by High Pressure Liquid Chromatography

Abstract

A quantitative determination of bicascarosides by HPLC in pharmaceutical preparations is described. These compounds are transformed by oxidative hydrolysis into their aglycones which can be separated on a RP-18 column. Concentrations as low as 0.05% can be determined without interference from monomeric aglycones.     

脂肪乳剂Intralipid代谢产物的高效液相色谱测定

本文介绍了利用ＨＰＬＣ色谱柱前衍生化技术简便，正确和灵敏地测定血清中游离脂肪酸的方法。在最佳条件下，一些脂肪酸的最低检知量为０．０４μｇ。方法已用于脂肪乳剂Ｉｎｔｒａｌｉｐｉｄ在诱发急性坏死性胰腺炎动物体内代谢产物测定。     

固相萃取-高效液相色谱法对血液中唑吡坦及其两种羧酸代谢物的同时测定

建立了固相萃取-高效液相色谱分析血液中唑吡坦、6-羧酸唑吡坦及苯基-4-羧酸唑吡坦的方法。采用Waters Oasis HLB 3 mL固相萃取小柱萃取,以乙腈-2.5 mmol/L醋酸铵水溶液为流动相,梯度洗脱,经ZORBAX Eclipse XDB-C18色谱柱(4.6 mm×250 mm,5μm)分离,二极管阵列检测器(DAD)检测,检测波长为250 nm,外标法定量。比较了不同洗脱溶剂、溶液pH值对回收率的影响。在优化条件下,唑吡坦、6-羧酸唑吡坦及苯基-4-羧酸唑吡坦的线性范围分别为40~2000μg/L(r=0.9999)、20~2000μg/L(r=0.9998)和40~2 000μg/L(r=0.9998),检出限为1.2~3.3μg/L。添加16、160、360μg/L 3个水平的混合标准溶液,3种化合物的回收率为86%~106%,相对标准偏差均小于8%。结果表明,该方法具有操作简便、回收率高、精密度好和灵敏度高等特点,适于血液中唑吡坦及其2个羧酸代谢物的分析,可为相关案件提供方法及技术支持。     

高效液相色谱法测定丁香酸及其杂质含量

研究了一种同时测定合成粗产品中丁香酸及其３,４－二羟基－５－甲氧基苯甲酸、３,４,５－三羟基苯甲酸以及３,４,５－三甲氧基苯甲酸含量的高效液相色谱法。用ＯＤＳ－３色谱柱,流动相为甲醇／水／３６％乙酸（４０：６０：２,Ｖ／Ｖ／Ｖ）,检测波长范围为２５０～３００ｎｍ,在选定的色谱条件下,各组份１５ｍｉｎ内实现基线分离。丁香酸、３,４－二羟基－５－甲氧基苯甲酸、３,４,５－三羟基苯甲酸以及３,４,５－三     

Simultaneous Determination of Fourteen Catecholamines and Their Metabolites by High Performance Liquid Chromatography with Electrochemical Detection

Abstract

A simple method has been developed for simultaneous determination of 14 catecholamines and their metabolites in cerebrospinal fluid and brain tissue by reversed-phase, ion-pair high-performance liquid chromatography with electrochemical detection. The time required for complete separation and analysis of all compounds was less than 35 min. Quantitation was based on the use of an internal standard isoproterenol. The mobile phase consisted of a 91:9 (v/v) mixture of 0.1 M formic acid and acetonitrile containing sodium-1-octane sulfonic acid. Using this method, analysis of neurotransmitters in brain tissue can be accomplished without a clean-up procedure.