高效液相色谱法测定血清中茶碱浓度

采用高效液相色谱,分析柱：３μｍ,３．３ｃｍ＊４．６ｍｍ,Ｉ．Ｄ（Ｐｅｒｋｉｎ Ｅｌｍｅｒ,ＵＳＡ）;预柱：１０μｍ,１ｃｍ＊２．１ｍｍ,Ｉ．Ｄ（Ｐｅｒｋｉｎ ＥＬｍｅｒ,ＵＳＡ）;以乙酰氨基酚为内标对氯仿－异丙醇（９５：５,Ｖ／Ｖ）提取样品进行了分析,流动相：０．１ｍｏｌ／Ｌ醋酸缓冲液（ＰＨ＝４．５）－甲醇（７０：３０,Ｖ／Ｖ）;检测波长：２７０ｎｍ;流速０．５ｍＬ／ｍｉｎ,３ｍｉｎ即完成一次茶     

Quantitation of Purines and Pyrimidines in Human Serum by High-Performance Liquid Chromatography

Abstract

A high-performance liquid chromatography assay was developed for the purpose of examining xanthine, hypoxanthine, uridine, thymidine, allopurinol, and oxypurinol in serum of patients with advanced carcinoma treated with methorexate and 5-fluorouracil. After the addition of an internal standard, serum samples were extracted of purines and pyrimidines with trichloroacetic acid and neutralized with tert-amine. Aliquots of the extracted serum were injected onto a C18 reverse-phase column and purines and pyrimidines were eluted with a gradient of MeOH/H₂O and KH₂PO₄ solutions. Absorbance was detected with a variable-wavelength UV spectrophotometer at 254 nm and 280 nm. This assay can be readily applied to quantitate baseline and treatment-induced variations in serum purine and pyrimidine levels which may correlate with clinical response and/or toxicity in patients with cancer.     

Rapid Quantitation of Verapamil in Plasma by High-Performance Liquid Chromatography

Abstract

A simple and sensitive liquid chromatographic assay procedure using a fluorescence detector for the quantitative determination of verapamil in plasma without extraction was developed. After precipitating the protein with acetonitrile, the resulting supernatant liquid was injected onto the column for analysis. Chromatographic separation was achieved on C₁₈ reversed phase column and the eluting solvent was the isocratic mixture of methanol, acetonitrile and pH 3.0 glycine buffer (1:4:5). With this mobile phase the drug and its internal standard were well separated from the interference of the plasma sample. The average recovery of verapamil from 3 replicate samples of different concentration (100–600 ng/mL) were 95.5 ± 5.68%. The minimum amount of verapamil detectable by this method was 40 ng/mL of sample. The elimination half-life (β-phase) of this drug in rabbits was found to be 3.7 hours.     

An Improved Microanalytical Procedure for the Quantitation of Procainamide and N-Acetyl Procainamide in Serum by High-Performance Liquid Chromatography

Abstract

A high-performance liquid chromatographic method for analysis of procainamide (PA), and N-acetyl procainamide (NAPA) is presented. Sample preparation employs a simple base-acid double extraction procedure and analysis is carried out on a reverse phase chromatographic system using a μBondapak C₁₈ column and buffered aqueous acetonitrile as the mobile phase. The extraction procedure gives quantitative recovery of both PA and NAPA, and chromatographic results show that drug levels of as low as 0.3 mg per liter of serum can be conveniently analyzed without significant background interferences. The small volume (0.2 ml) of serum needed to perform an analysis makes this method suitable for pharmacokinetic studies in humans and animals as well as for clinical therapeutic drug monitoring studies.     

Quantitation of Baclofen in Tablets Using High-Performance Liquid Chromatography

Abstract

A reverse phase high-performance liquid chromatography method has been developed to quantify baclofen in tablets. The method is accurate and precise with a percent relative standard deviation of 0.52 based on 5 readings. The recovery from the synthetic mixtures was quantitative. The results were in excellent agreement with the USP-NF colorimetric method. The method can be used to test the content uniformity of the tablets. Samples which were treated with either sulfuric acid or sodium hydroxide and boiled for 10 minutes did not show new peaks in the chromatogram. Baclofen appears to be a very stable compound.     

Determination of Acyclovir in Human Serum by High-Performance Liquid Chromatography

Abstract

A method was developed for determination of concentrations of acyclovir in serum. Serum proteins were precipitated with equal part of 5% perchloric acid. High-performance liquid chromatography was used for separation from endogenous compounds and detection was done with spectrophotometry. The assay is simple and precise and seems well suited for pharmacokinetic studies.     

Determination of Serum Phospholipid Metabolic Profiles by High-Performance Liquid Chromatography

Abstract

A method for the separation of serum phospholipid molecular species by reversed-phase high-performance liquid chromatography is described. Total serum phospholipid extracts were hydrolyzed with phospholipase C and benzoylated, and the resulting monoglyceride, diglyceride, and ceramide derivatives were separated by using gradient elution with detection at 230nm. Both human and rat serum phospholipid extracts were examined, and the use of this method for the evaluation of serum phospholipid metabolic alterations accompanying exposure to an environmental toxicant (polybrominated biphenyls) is described.     

Quantitation of Chlorpropamide and Tolbutamide in Tablets by Stability-Indicating Reverse Phase High-Performance Liquid Chromatography

Abstract

A stability-indicating assay method for the quantitation of chloropropamide and tolbutamide based on reverse phase high-performance liquid chromatography has been developed. The method is accurate, reproducible and precise with a percent relative standard deviations based on 5 readings of 0.52 and 0.46 for chlorpropamide and tolbutamide, respectively. There is no interference from the products of hydrolysis of chlorpropamide or tolbutamide (they elute before the intact drug) and th excipients present in the tablets. The hydrolysis process proceeds very fast in acidic pH as compared with basic pH. The products of hydrolysis, p-chlorobenzenesulfonamide (from chlorpropamide) and p-toluenesulfonamide (from tolbutamide) can also be quantified if required. The hydrolysis of both chlorpropamide and tolbutamide in 0.09N H₂SO₄ followed first order law with K values of 0.0036 and 0.0047 per day (at 50°), respectively.     

A Method for the Determination of Methionine in Human Serum by High-Performance Liquid Chromatography with Electrochemical Detection

Abstract

We have found remarkable enhancement of electrochemical response for the analysis of methionine by use of a glassy carbon electrode preanodized in a 0.2 M phosphate buffer (KH₂PO₄?KOH, pH 6.5) at +1.9 V vs. Ag/AgCl for 2 min. On the basis of this finding, we have developed a method for the determination of methionine in human serum by reversed-phase high-performance liquid chromatography with electrochemical detection using the electrochemically pretreated glassy carbon electrode. The minimum detectable quantity of methionine has been found to be about 1 ng.     

A Simplified Extraction for Mexiletine from Serum and Analysis by High Performance Liquid Chromatography

Abstract

The analysis of mexiletine by High Performance Liquid Chromatography (HPLC) requires organic extraction followed by evaporation of the organic solvent. Calibration curves must be prepared using standards in drug-free serum. This procedure has been simplified by using a back extraction of the mexiletine from serum. Calibration curves can then be more quickly prepared since good agreement can be obtained using standards in hydrochloric acid (HCl) instead of having to prepare standards in serum with the time-consuming necessity of having to extract these standards.     

Measurement of Cefixime in Serum and Cerebrospinal Fluid by High-Performance Liquid Chromatography

Abstract

Cefixime is a new cephalosporin antibiotic for oral administration. A high-performance liquid chromatographic (HPLC) method was developed to measure cefixime in small volumes of serum and cerebrospinal fluid (CSF) to conduct a pharmacokinetics study in pediatric patients. The assay involved precipitation of serum proteins with 6% trichloroacetic acid, using 7-hydroxycoumarin as an internal standard. Chromatographic separation was accomplished using ultrasphere C8 column and mobile phase containing 15% acetonitrile in a buffer at a detection wave length of 280 nm. The retention time of cefixime and 7-hydroxycoumarin was about 5 and 9 minutes, respectively. The method was suitable for quantitation of cefixime at a concentration ranging from 0.05 to 10 μg/ml. The coefficient of variation was less than 3%. The technique was used successfully to measure cefixime in serum and CSF obtained from an infant receiving cefixime.     

Micro-Scale Method for Determination of Tobramycin in Serum Using High-Performance Liquid Chromatography

Abstract

A rapid, simple, accurate, and micro-scale method for the determination of tobramycin, sisomicin and netilmicin in serum using high-performance liquid chromatography has been developed. The method is sensitive to 0.3 pg/ml using only 20 μl of serum. The serum is deproteinized with methanol containing an internal standard: sisomicin for the tobramycin, netilmicin for the sisomicin, and sisomicin for the netilmicin. After centrifugation, a counter-ion reagent is added to the supernatant, then an aliquot of the solution is injected into the chromatograph. Tobramycin, sisomicin and netilmicin are separated by reversed-phase, ion-pair chromatography and detected by fluorescence using continuous-flow, post-column derivatization with o-phthalaldehyde. For the tobramycin, within-run and day-to-day variation was below 2.5%. Correlation of this method with microbiological assay and homogeneous enzyme immunoassay was good.     

用亲水性的C16硅胶反相色谱柱分离测定血清样品中的雌激素

将亲水性较强的C16硅胶反相色谱柱应用于血清样品中β-雌二醇、雌三醇、雌酮和17α-乙炔基雌二醇的分离。实验对分离条件进行了优化,得到的最佳色谱条件是：柱温40℃,流速1mL／min,以40％乙腈水溶液作等度洗脱。在此条件下．4种雌激素可在大约26min内实现基线分离,得到的4个色谱峰峰型对称。分离后的4种雌激素用紫外检测器在200nm处进行测定,方法对β-雌二醇、雌三醇、雌酮和17α-乙炔基雌二醇的检出限分别为0．024、0．015、0．012和0．016mg/L;校正曲线的线性范围为2-3个数量级,相关系数为0．998以上。方法应用于血清样品的测定,β-雌二醇、雌三醇、雌酮和17α-乙炔基雌二醇的标准加入回收率分别为96．3％、103．7％、100．1％和95．2％。     

Tocainide Determination by High-Performance Liquid Chromatography

Abstract

Tocainide has been assayed after serum deproteinization with acetonitrile by HPLC. The pH was critical in separating the drug from other interferences in the serum. The method is simple and fast.     

Determination of Ofloxacin,A New Oxazine Derivative in Human Serum,Urine, and Bile by High-Performance Liquid Chromatography

Abstract

A simple and precise high-performance liquid procedure has been developed for the determination of Ofloxacin (DL-8280), a new oxazine derivative in human serum, urine and bile using Norfloxacin as internal standard. The work-up procedure involves a chemical extraction step followed by isocratic chromatography on a anion-exchange analytical column, with ultraviolet detection. The run time for the assay was 11.5 minutes.     

High-Performance Liquid Chromatography of New Semisynthetic Daunomycinone Derivatives

Abstract

Reversed-phase HPLC utilizing LiChrosorb RP-8 was used to separate reaction mixtures of new semisynthetic daunomycinone derivatives and determine their relative occurrence.

Chromatographic behaviour of the following compounds was studied: daunomycinone (I), 7(S) and 7(R)-0-(2-hydroxyethyl)-13-ethyleneacetal daunomycinone (II and III), 13-ethyleneacetal daunomycinone (IV), 13-ethyleneacetal bisanhydrodaunomycinone (V), 7(S) and 7(R)-0-(3-hydroxypropyl)-13-propyleneacetal daunomycinone (VI and VII), 13-propyleneacetal daunomycinone (VIII), 13-propyleneacetal bisanhydrodaunomycinone (IX), 7(S) and 7(R)-0-(4-hydroxybutyl) daunomycinone (X and XI), 4-toluenesulfonylhydrazone daunomycinone (XII).     

Quantitation of Toremifene and its Major Metabolites in Human Plasma by High-Performance Liquid Chromatography Following Fluorescent Activation

Abstract

A highly sensitive reverse-phase high-performance liquid chromatography assay utilizing fluorescence activation has been developed for the quantitative analysis of the anti-estrogenic compound toremifene and its major metabolites, 4-hydroxy-toremifene and N-desmethyl-toremifene. Plasma samples containing various quantities of toremifene and its metabolites were spiked with an internal standard (nafoxidine), extracted with 2% n-butanol in hexane, and irradiated with high intensity ultraviolet light (254 nm). Aliquots of the extracted plasma components were then injected onto a C-18 reversed phase column and eluted isocratically with a mobile phase of water and triethylamine in methanol. Fluorescence of toremifene, its metabolites, and internal standard was measured at an excitation wavelength of 266 nm. -The sensitivity of this assay was 8.0, 15.0 and 5.0 ng/mL for toremifene, N-desmethyl-toremifene and 4-hydroxy-toremifene, respectively. Linearity was achieved for the concentration range of 25 to 400 ng/mL for all the compounds, with correlation coefficients of greater than 0.994. The assay presented is highly specific, very sensitive and demonstrates reproducible linearity throughout a wide range of clinically relevant plasma toremifene concentrations.     

High-Performance Liquid Chromatographic Analysis of Theophylline in the Presence of Caffeine in Blood Serum and Pharmaceutical Formulations

Abstract

A reversed phase high-performance liquid chromatographic (HPLC) method has been established for the separation and quantitative determination of the alkaloid theophylline in the presence of caffeine -internal standard- in blood serum and in pharmaceutical preparations. The separation was performed on Spherisorb-5 RP-18 5μm reversed phase column using methanol: 0.038 M ammonium acetate: acetonitrile (38: 57:5) at a pH of about 7.20. The eluted alkaloids are detected at 272 nm. The retention time is 3.09 min for theophylline and 3.85 min for caffeine. The correlation of the integrated peak area with the concentration of theophylline showed a linear relationship between 0.05 to 5.0 theophylline in blood serum, tablets, sprinkels, syrups, suppositories and injectable solutions.     

Urinary Tyramine Assay by High-Performance Liquid Chromatography

Abstract

An assay for urinary tyramine based on its reaction with fluorescamine and subsequent separation on reverse phase column has been described. The method is simple, sensitive and free from interferences. Patients with neuroblastoma, pheochromocytoma and Parkinson's disease have elevated levels of urinary tyramine.