Determination of Carbonyl Compounds by High-Performance Liquid Chromatography

Carbonyl compounds in the form of 2,4-dinitrophenylhydrazones in alcoholic solutions were analyzed by high-performance liquid chromatography. This simple procedure is characterized by high sensitivity and reproducibility.     

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 Benzylpenicillin, Levomycetin (Chloramphenicol), and Tetracycline in Food Products by High-Performance Liquid Chromatography

A procedure was developed for the extraction of antibiotics from food products followed by extract cleanup and analysis using reversed-phase high-performance liquid chromatography.     

Determination of Monobromobimane-Labeled Phytochelatins by High-Performance Liquid Chromatography

A new method for phytochelatins by high-performance liquid chromatography (HPLC) was developed based on a condensation reaction with monobromobimane to produce fluorescent derivatives. Glutathione, H-(γ-glutamic acid-cysteine)₂-glycine-OH, H-(γ-glutamic acid-cysteine)₃-glycine-OH, H-(γ-glutamic acid-cysteine)₄-glycine-OH, H-(γ-glutamic acid-cysteine)₅-glycine-OH, and H-(γ-glutamic acid-cysteine)₆-glycine-OH were well separated, with retention times between 14.68 and 22.0 min. The HPLC method had good linearity (r < 0.9991) between 0.1 mg L^?1 and 100 mg L^?1. The limits of quantification for the analytes (S/N = 3) were 0.08, 0.3, 0.05, 0.3, 0.5, and 0.8 mg L^?1, respectively. The recoveries were between 83.0% and 101.33% with relative standard deviations less than 2%. The reported method is simple, accurate, and suitable for the determination of phytochelatins.     

Determination of Dialkyltin Compounds in Poly(Vinyl Chloride) by High-Performance Liquid Chromatography

A high-performance liquid chromatography (HPLC) method has been developed for the analysis of dialkyltin compounds in polyvinyl chloride (PVC) materials. The PVC sample was first dissolved in tetrahydrofuran. Concentrated hydrochloric acid was then added to convert the dissolved dialkyltin stabilizers into the chloride forms, followed by extraction with hexane. The extracted dialkyltin chlorides were preconcentrated and were finally separated by HPLC. Separation was performed using a C₁₈ column and an eluent of aqueous methanol containing 8-hydroxyquinoline (oxine) as the completing agent. Photometric detection of the dialkyltin-oxine complexes was carried out at 380 mm. Under optimum experimental conditions, the detection limits for dimethyltin, dibutyltin and dioctyltin are 1.7 ng, 2.1 ng and 2.9 ng (all as tin), respectively. Residual dialkyltin stabilizers in several commercially available PVC products were successfully analyzed via this method.     

高效液相色谱法测定环己铜过氧化物

以甲醇或甲醇与水作流动相,ODS为固定相,测定环己酮的多种过氧化物。平均回收率100.2％～101.6％,测定的相对标准偏差为1.02％～2.51％。     

Simultaneous Determination of Food-Related Amines by High-Performance Liquid Chromatography

Abstract

Ten amines found in marine foods, dimethylamine, trimethylamine, trimethylamine oxide, ammonia, urea, histamine, cadaverine, putrescine, spermine and spermidine were separated by HPLC using an ion-moderated partition column. Optimum resolution and sensitivity were obtained using 0.003N sodium hydroxide as the mobile phase and UV detection at 208 nm.     

Quick and Simple Determination of Dihydroergotamine by High-Performance Liquid Chromatography

Abstract

A simple and rapid liquid chromatographic assay method using a fluorescence detector for quantitation of dihydroergotamine in plasma without extraction was developed. After precipitating the protein with acetonitrile, the supernatant liquid was directly injected for analysis. Chromatographic separation was achieved on C₁₈ reversed phase column and the mobile phase was the isocratic mixture of methanol, acetonitrile and glycine buffer (0.5:3.5:6.0). With this eluting solvent the drug and its internal standard were well separated from the interference of the plasma sample. The average recovery of dihydroergotamine from 6 replicate samples of different concentrations (5-30 ng/ml) were 92.2 ± 3.37%. The minimum amount of dihydroergotamine detectable by this method was 2 ng/ml of sample.     

Determination of Atenolol and Its Related Compounds by Ion Pair High Performance Liquid Chromatography

Abstract

A rapid, simple, accurate, and stability-indicating ion pair high performance liquid chromatography (IP HPLC) procedure is presented for the determination of atenolol in pharmaceutical tablets. The related compounds of atenolol were separated, making the determination specific for atenolol. An aliquot of the sample is dissolved in methanol containing N-butyryl-4-aminophenol as an internal standard and chromatographed on a supelcosil LC-8-DB (5μ) (25Omm × 4.6mm i.d.) column using 1.0 mM ammonium acetate and 2.0 mM octanesulfonic acid sodium salt in acetonitrile: water (25:75) solution adjusted to pH 3.5 with glacial acetic acid as the mobile phase. The detection was carried at 225 nm. The relative standard deviations are less than 1.0% for the two commercial products analyzed. The method was tested for linearity, recovery, and specificity.     

Simultaneous Determination of Pioglitazone and Glimepiride by High-Performance Liquid Chromatography

A rapid and accurate HPLC method has been developed for simultaneous determination of pioglitazone and glimepiride. Chromatographic separation of the two pharmaceuticals was performed on a Cosmosil C₁₈ column (150 mm × 4.6 mm, 5 m) with a 45:35:20 (v/v) mixture of 0.01 m triammonium citrate (pH adjusted to 6.95 with orthophosphoric acid), acetonitrile, and methanol as mobile phase, at a flow rate of 1.0 mL min^–1, and detection at 228 nm. Separation was complete in less than 10 min. The method was validated for linearity, accuracy, precision, limit of quantitation, and robustness [1, 2]. Linearity, accuracy, and precision were found to be acceptable over the ranges 2.50–30.00 g mL^–1 for pioglitazone and 0.10–10.00 g mL^–1 for glimepiride.     

反相高效液相色谱法测定阿奇霉素及其相关化合物

建立了利用简单流动相组成测定阿奇霉素及其相关化合物的反相高效液相色谱法,色谱柱为InertsilODS 3(150mm×4. 6mm, 5μm),流动相为乙腈水(90∶10,V/V),流速0. 8mL/min,柱温30℃;紫外检测波长为205nm。能够明确地分辨阿奇霉素粗品中5种物质:红霉素6, 9亚胺醚、红霉素9, 11亚胺醚、阿奇霉素前体、甲基化硼酸酯和阿奇霉素。该方法简便快捷,线性关系良好,结果准确可靠,对阿奇霉素合成工艺优化和成品的质量检测均具有指导作用。     

Determination of Plasma Levels of Bupivacaine by High-Performance Liquid Chromatography

Abstract

We evaluate a method for determination of bupivacaine using HPLC, and the possibility of pharmacological interferences produced by seven commonly used drugs administered before, during and after surgery: diacepam, midazolam, epinephrine, naloxone, flumacenil, atropine and ephedrine. The method has an average recovery of 102.8 +/? 5.4%. The detection limit is 0.125 μg/mL. The within-day coefficient of variation is 5.88% and the between-day coefficient of variation is 15%. We haven't found drug interferences at generally encountered serum concentrations.     

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 Cefpirome in Human Plasma by High-Performance Liquid Chromatography

Abstract

Cefpirome is an investigational third-generation cephalosporin, which appears promising for the treatment of various pediatric infections. A high performance liquid chromatographic method was developed to measure cefpirome in small volumes of plasma for conducting pharmacokinetics studies in infants and children. the assay involved precipitation of plasma proteins with acetonitrile, using cefaclor as an internal standard. Chromatographic separation was accomplished using a reverse-phase     

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     

Determination of Pyridostigmine in Human Plasma by High-Performance Liquid Chromatography

Abstract

An easy to perform, specific, reproducible and sensitive high performance liquid chromatographic (HPLC) method to measure pyridostigmine concentration in human plasma was developed and validated. Sample clean-up consists of ion-pair extraction into dichloromethane in the presence of neostigmine as internal standard, followed by back extraction into an aqueous phase. Mean recovery of 110% (with a standard deviation of 10%) was determined for concentrations of 5 – 100 ng/ml. Chromatography on a 125·4 mm CN-propyl column using a mobile phase composed of 10% acetonitrile in 3.5×10^?4M NaH₂PO₄ and UV detection at 270 nm, yields clean chromatograms without any interferences from endogenous plasma components. Using 1 ml plasma samples the method has a limit of detection (LD) of 3 ng/ml, with %CV (precision) and bias (accuracy) ≥ 10% for concentrations in the range of 0–100 ng/ml. The method is being used in human pharmacokinetic studies of oral dosage forms of pyridostigmine.     

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.     

高效液相色谱法测定有机肥中洛克沙胂

建立了高效液相色谱(HPLC)-串联紫外检测法检测有机肥中洛克沙胂的分析方法。选用20g·L-1K2HPO4作为提取剂,于60℃温度下超声提取有机肥中的洛克沙胂,采用MAX固相萃取柱净化。结果表明,采用Symmetry ShieldTMRP 18色谱柱,以含0.1%甲酸的0.05mol·L-1 KH2PO4∶甲醇=95∶5(V/V)溶液作流动相,等度洗脱,紫外266nm检测,洛克沙胂的保留时间短,且可完全避开杂质峰的干扰;其平均加标回收率介于81.14%~82.75%之间,相对标准偏差(RSD)7.0%,检出限为20μg·L-1。方法重现性好,精密度高,操作简便,适用于有机肥中洛克沙胂检测。     

Analysis of Triorganotin Compounds by High-Performance Liquid Chromatography with Reverse-Pulse Amperometric Detection

High-performance liquid chromatography (HPLC) coupled with the reverse-pulse amperometric (RPA) detection method has been developed for the analysis of triorganotin compounds in aqueous solutions. The major advantage of RPA vs. conventional amperometric detection is its ‘in situ’ elimination of interference from dissolved oxygen in the chromatographic eluent; therefore, no extra chemicals or apparatus are required for oxygen removal. With a Partisil-10 SCX column and an eluent of methanol/0.01 M sodium acetate buffer (70:30, pH 5.5), the four triorganotins, viz., trimethyl-, triethyl-, tripropyl-, and tributyltin, can be totally separated. Detection by RPA was performed with a static dropping mercury electrode with an initial potential of ?1.15 V and a final potential of +0.15 V. The absolute detection limit (S/N = 3) ranged from 12 ng of tributyltin (as tin) to 0.3 μg of trimethyltin (as tin). Applications of the method to the analysis of trace tributyltin in marine antifoulant leachate and sea water are described.     

Determination of Vitamins in Feed and Foodstuffs by High-Performance Liquid Chromatography

Procedures were developed for the HPLC determination of fat- and water-soluble vitamins extracted from feed and foodstuffs. The optimum conditions for the extraction of vitamins and their subsequent determination were found.