Application of high-performance liquid chromatography for the simultaneous determination of morphine,codeine, and caffeine

A procedure is described for the simple and rapid simultaneous determination of morphine, codeine, and caffeine in biological fluids. The detection limits were 0.4 ng for caffeine, 0.9 ng for morphine, and 0.6 ng for codeine with an analysis time of under 6 min. The preferred system employs a column packed with octacylsilate bonded onto 10-μm porous silica gel, reverse phase, and a RP-8 Spheri-5 guard column. An eluting system of methanol: 0.25% (w/v) aqueous ammonium acetate (70:30) was found to be best. The standard deviation was not more than 0.5 for caffeine, one for morphine, and 1.2 for codeine. Drug recovery from 50 μl urine and blood samples was better than 90.0%.     

An Evaluation of High Performance Liquid Chromatography-UV for the Multi-Residue Analysis of Organophosphorous Pesticides in Environmental Water

Abstract

In this study isocratic high performance liquid chromatography in the reversed-phase mode (RP-8 or RP-18 column) with UV-detection (254 nm), was evaluated for the analysis, directly or after extraction, of organophosphorous pesticides in environmental water.

Fifteen pesticides were studied and good resolution was obtained for eight by direct analysis of a multi-residue water sample. Reproducibility in terms of retention times was found to be very good. Linear calibration curves were obtained down to 0.5ng/μL (3 ng injected) with a coefficient of variation near 10%. The limit of quantitation for direct analysis was found to be 0.5mg/L (3ng) in water. However, by extraction with methylene chloride or ethyl acetate and concentration of the extract some of the pesticides could be determined at 0.5 μg/L (ppb) in water.     

A Rapid Isocratic Reversed-Phase Separation and Determination of Some Barbiturates by High-Performance Liquid Chromatography

Abstract

A high performance liquid chromatographic method for the rapid separation and quantitative determination of five barbiturates in pharmaceutical preparations and body fluids has been developed. A C₁₈ reversed phase column was used and the barbiturates were detected at 235nm.

A number of eluting systems were examined, the most suitable of them being, Ethanol:Propanol:Methanol:Water (26:5:29:40) at pH = 8.8.     

Trace Enrichment and HPLC Analysis of Chlorophenols in Environmental Samples,Using Precolumn Sample Preconcentration and Electrochemical Detection

Abstract

A HPLC method has been developed for trace analysis of chlorophenols in the 0.2–2 ppb range from spiked water samples. Simple liquid-liquid extraction followed by on-line preconcentration of total mono- and dichlorophenols has been performed using a divinylbenzene-styrene copolymeric sorbent (PRP₁) as packing material for the precolumn. The chlorophenols have been eluted from the precolumn on an analytical column (5μm LiChrosorb RP-18, 12.5 cm × 4 mm) by use of a switching valve system followed by separation. Detection was carried out with an electrochemical detector. The linearity of the detector response has been proved over two orders of magnitude. The detection limit of chlorophenols by means of the electrochemical method is in the lower picogram range. The recoveries of the isomeric chlorophenols from spiked river water samples having initial concentrations of 2ppb are usually 70–90%. The procedure has been applied to drinking water and river water.     

High Performance Liquid Chromatographic Separation of Bryostatins 1–12

Abstract

A reversed-phase high performance liquid chromatographic (RP-8; acetonitrile-water gradient) separation procedure was developed for detecting bryostatins 1–12, using a photodiode array detector system. While bryostatins 6 and 9 were found to co-elute they were easily separated using a silica gel column with 9:1 n-hexane-n-propanol as eluent.     

Effect of Alkyl Chain Length of Bonded Silica Phases on Separation,Resolution and Efficiency in High Performance Liquid Chromatography

Abstract

A comparative study of alkyl bonded phases was carried out under optimum solvent conditions for each phase. Three columns, RP-2, RP-8 and RP-18, were tested for their efficiency and resolving power using three groups of compounds in three binary organic-water mobile phases. The organic solvents were acetonitrile, methanol and tetrahydrofuran which are widely used as solvent modifiers.

The results indicate that each of the three factors, i.e. solvent, solute and bonded alkyl chain length, play an important role, with the solvent being the most significant. When tetrahydrofuran-water was used as the mobile phase, the ratio of THF/H₂O did not vary by much when an RP-2, RP-8 or RP-18 column was used to separate naphthalene from biphenyl, dimethylphthalate from diethylphthalate or anthraquinone from methyl, anthraquinone and ethyl anthraquinone. When acetonitrile-water and methanol-water were used the ratio of organic modefier to water changed so as to accomodate the hydrophobic properties of the columns. The efficiency of the columns, expressed as theoretical plates per meter (TPM) was highest when acetonitrile-water was used as the mobile phase. Although there were variations in TPM and resolution from column to column, the three columns gave good separation of the components of the three groups of compounds.     

Analysis of Sucrose Fatty Acid Esters Composition by HPLC

Abstract

Two procedures for quantitative analysis of sucrose fatty acid esters composition using HPLC are described. A reversed-phase column (RP-18) was used. The mobile phases consist of: a) methanol (95%) and isopropanol (5%); b) methanol and water (5%) using UV and RI detectors.     

High Performance Liquid Chromatographic Analysis of Penicillin V Solid Dosage Forms

Abstract

An isocratic high performance liquid chromatographic (HPLC) method for the determination of Penicillin V in solid dosage forms is described. A reverse phase RP-8 column and a mobile phase of 52% methanol in 0.05 M phosphate buffer (pH 3.3) were employed. Detection was effected at 254 nm. The results obtained are compared with those from the iodometric method.     

High Performance Liquid Chromatographic Analysis of Rifampin and Related Impurities in Pharmaceutical Formulations

Abstract

High pressure liquid chromatography was employed for the assay of rifampin in capsules. A reverse phase RP-2 column and a mobile phase of 48% methanol, 5% tetrahydrofuran and 47% 0.05 M ammonium formate (pH 7.3) were used with detection at 254 nm. Rifampin was separated from all its major degradation products and quantitated.     

Simultaneous Determination of Warfarin,Sulphaquinoxaline and Fenitrothion in Wheat-Based Rodenticide Baits by High Pressure Liquid Chromatography

Abstract

The simultaneous determination of warfarin, sulphaquinoxaline and fenitrothion in wheat-based rodenticides is achieved by extracting the three components from the bait with dimethylformaaide followed by an isocratic, high-pressure liquid chromatographic separation using a reverse-phase RP-8 column and 0.005 M pentane sulphonic acid in methanol:water (60:40) as eluent. The three components are detected at 280 nm after separation. Recoveries in the concentration range investigated were fenitrothion 97.2%, warfarin 97.8% and sulphaquinoxaline 96.9%.     

A Reverse Phase HPLC Assay for the Determination of Calcium Pantothenate Utilizing Column Switching

Abstract

A reverse phase HPLC assay utilizing column switching has been developed and validated for the determination of calcium pantothenate (CP) in several multivitamin tablet formulations. The reverse phase system utilizes a DuPont Zorbax C-8 analytical column, an automatically switched and backflushed Brownlee RP-18 guard column for the elimination of a highly retained excipient peak, 88:12 0.25M phosphate buffer:MeOH mobile phase, and 214 nm detection. Sample preparation and the switched column chromatography cycle each require approximately 15 minutes. A spiked recovery study showed linearity over the 50–150% of theory concentration range. Average recovery was 99.7%. Assay precision studies yielded sample RSD's ranging from 0.8 to 2.3%. Results obtained by this method are comparable to those obtained by the USP method.     

A Simple and Rapid Reversed Phase High Performance Liquid Chromatographic Method for Quantification of Alprazolam and α-Hydroxyalprazolam in Plasma

Abstract

A simple and rapid reversed-phase liquid chromatographic method for the determination of alprazolam and a-hydroxyalprazolam in plasma is described. Flunictrazepam was used as internal standard. Plasma samples were buffered with sodium borate and extracted with dichloromethane /n-pentane 4:6 v/v for 60 sec on a vortex apparatus. Extraction solvent was evaporated to dryness and extraction residues were reconstituted in the mobile phase. Samples were chromatographed on a 5μ Lichrospher RP-18 column (25cm × 4mm i. d) using acetonitrile/water 40:60 v/v as the mobile phase. The column effluent was monitored at 230nm. The lower limit of detection was 1ng/ml for alprazolam and a-hydroxyalprazolam while the lower limit of quantification was 2ng/ml for both compounds. Peak height and plasma     

HPLC Quantification of Azintamide and Papaverine Hydrochloride Simultaneously in Pharmaceutical Preparations

Abstract

A simple HPLC-procedure for quantification of azintamide and papaverine. HCl simultaneouly in dosage formulations has been investigated. The complete resolution and quantitative determination of both drug substances has been undertaken on a Hibar 100RP-18 Lichrospher (5 μm) column by using a solvent mixture composed of acetonirile – water (56:44, v/v) isocratically at a rate of 1 ml·min^?1with UV-detection at 240 nm. Recovery percentages of 100.39 ± 0.70 (n = 12) and 99.97 ± 1.11 (n = 12) were obtained for added azintamide and papaverine. HCl, in order.     

Method for quantification of morphine and its 3- and 6- glucuronides, codeine, codeine glucuronide and 6-monoacetylmorphine in human blood by liquid chromatography-electrospray mass spectrometry for routine analysis in forensic toxicology.

Simultaneous determination of opiates and their glucuronides in body fluids has a great practical interest in the forensic assessment of heroin intoxication. A selective and sensitive method for quantification of morphine and its 3- and 6-glucuronides, codeine, codeine glucuronide and 6-monoacetylmorphine (6-MAM) based on liquid chromatography-electrospray ionisation mass spectrometry is described. The drugs were analysed in human autopsy whole blood after solid-phase extraction on a C8 cartridge. The separation was performed on an ODS column in acetonitrile (analysis time 15 min). For the quantitative analysis, deuterated analogues of each compound were used as internal standards. Selected-ion monitoring was applied where the molecular ion was chosen for quantification. The limits of quantification were 0.5 ng/ml for morphine and 6-MAM and 1 ng/ml for the 6-glucuronide of morphine, codeine-6-glucuronide and codeine and 5 ng/ml for the 3-glucuronide of morphine.     

A Method for the Determination of Octa- and Nonachloro-2-phenoxyphenols in Chicken Tissue

Abstract

A gas-liquid chromatographic method was developed capable of determining octa-and nonachloro-2-phenoxyphenols in chicken liver or muscle at 0.25 ppb and fat at 2.5 ppb. The method involves extraction with acidified acetone:hexane, cleanup with concentrated H₂SO₄ and Florisil column chromatography, methylation with diazomethane, and quantitation by capillary column gas-liquid chromatography with electron capture detection. Fortification of liver and muscle at 0.25 or 0.5 ppb and fat at 2.5 or 5.0 ppb and subsequent analysis yielded recoveries averaging 91% for octa-and 97% for nonachlorophenoxyphenol.     

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.     

A Rapid Method for Determination of Progesterone By Reversed-Phase Liquid Chromatography from Aqueous Media

ABSTRACT

A simple reversed-phase liquid chromatographic method to assay progesterone in aqueous receiving medium, following in vitro skin permeation studies is presented. Progesterone was analysed using 5 μm LichroCART® RP-18 column (125 × 4 mm i.d.), after extraction with chloroform. The mobile phase used was methanol:water (70:30) at a flow rate of 1 ml/min. Detection was carried out at 254 nm at room temperature. The method showed a mean recovery of 99% for progesterone, and intra-assay and inter-assay coefficients of variation were below 2%. The proposed method was validated for linearity, specificity, precision and accuracy and showed to be useful for analysis of progesterone in in vitro skin permeation studies.     

Determination of Reserpine in Pharmaceutical Formulations by High Performance Liquid Chromatography

Abstract

High performance liquid chromatography was employed in the assay of reserpine in tablet formulations. A reverse-phase RP-8 column was used and reserpine was separated from its major degradation products and quantitated by peak-height measurement using ultraviolet detection at 254 nm and fluorescence at 330 nm excitation. Tablets analysed were within the official limits even after more than ten years following manufacture.     

High Performance Liquid Chromato-Graphic Method For The Determination Of Permethrin Deposits In A Forestry Spray Trial

Abstract

A convenient and sensitive reversed-phase high performance liquid Chromatographie method has been developed for the determination of perraethrin [3-phenoxybenzyl (±)- cis,trans -3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylate] insecticide. Various isocratic and gradient mobile phases, consisting of acetonitrile:water (CH₃CN:H₂O) and methanol:water (CH₃OH:H₂O) solvent systems at two flow rates, were tested to separate and quantify the Isoners of permethrin using octadecylsilyl (ODS) (Regis 5μ m) and octylsilyl (OS) (RP-8, 10 μ m) bonded columns. The optimal mobile phase for perraethrin using the ODS column was 70:30 (v/v) CH₃CN:H₂O mixture at flow rates of either 1.0 or 1.5 mL/min. The measurement was done with a UV detector at 200 nm and 50°C. The OS column gave a less satisfactory separation than the ODS. Gradient elution systems examined did not improve the iso-meric separation of perraethrin. Using the method developed, deposit levels obtained on various sampling units during a perraethrin spray trial were analyzed after elution or extraction followed by necessary column cleanup. Minimum levels of detection for permethrin varied from 1 to 3 ng depending on the nature of the sampler used.     

Analysis of Phosmet and Azinphos-Methyl in Apples by High-Performance Liquid Chromatography

Abstract

A high-performance liquid chromatography (HPLC) method has been developed to analyze two organophosphate insecticides (phosmet and azinphosmethyl) in apples. The procedure includes a novel extraction whereby whole apples are sonicated for 2 min in 100 ml of MeOH to remove the pesticides. Reversed-phase HPLC separation was accomplished with an Ultremex C18 column and acetonitrile:methanol:water as the eluent. Detection was at 224 nm for phosmet and 300 nm for azinphos-methyl. For both pesticides the limit of detection was 0.5 ppb and the linearity was from 1 to 405 ng injected. Average recoveries were 80% for phosmet and 86% for azinphos-methyl. Thirteen apple varieties comprising 240 apples were analyzed from supermarkets and roadside stands for phosmet (amount found ranged from none detected to 1233 ppb) and azinphos-methyl (amount found ranged from none detected to 388 ppb). Confirmation of phosmet and azinphos-methyl was made by UV spectral scans.