The Use of HPLC/Thermospray Ms for the Confirmation of Aflatoxins in Peanuts

Abstract

An HPLC/Thermospray MS method is described for the determination of aflatoxins B₁, B₂, G₁ and G₂ in peanut extracts. Samples are extracted and prepared for analysis using an SPE method. The final determination utilizes reversed phase HPLC with a thermospray MS detector. The use of the MS allowed for unequivocal identification of aflatoxins in the extracts.     

High Performance Liquid Chromatogrphy of Fat-Soluble Vitamins. III. Determination of Vitamin D3 in Pharmaceutical Preparations and in Blood

Abstract

A reversed phase high-performance liquid chromatographic method (HPLC) is described for separation and determination of colecalciferol (Vitamin D₃) in Vitamin preparations and in biological materials. Vitamin D₃ is extracted from the formulations and from the blood in a fully automated electronically controlled extraction apparatus. For HPLC a column of lichrosorb RP18 and methanol as eluent are used. The extraction, separation and determination of vitamin D₃ needs about 10–20 minutes. The described extraction and HPLC methods allow the detection of 1–2 ng per injection and are well reproduced with a maximum coefficient of variation of < 3,5%. Vitamin A-acetate is used as internal standard.     

The Determination of Sodium Monofluoroacetate (Compound 1080) in Formulation and Technical Samples by High Pressure Liquid Chromatography

Abstract

A high pressure liquid chromatographic (HPLC) procedure was developed for the determination of sodium monofluoroacetate (Compound 1080). The procedure utilized an amine (NH₂) bonded column for the reverse phase determination of sodium monofluoroacetate in formulation and technical samples.     

Serum Injection of the HPLC Column for Carbamazepine Assay

Abstract

Serum was injected directly on an HPLC column packed with C₁, 6.5 μm particle size, 300 Å pore-packing material for carbamazepine determination. The use of a wide-pore column with low hydrophobicity eliminated excessive pressure buildup in the column from protein precipitation which is usually caused by the high concentration of organic solvents in the mobile phase. This simple approach can be utilized for the determination of other drugs and endogenous compounds in serum.     

Aflatoxin Analysis by Reverse Phase HPLC Using Post-Column Derivatization for Enhancement of Fluorescence

Abstract

The application of a technique for the determination of aflatoxins by reverse phase HPLC and fluorescence detection incorporating post-column derivatization with iodine, is described. The procedure proved to be extremely sensitive and reproducible. Chromatograms of extracts from maize, peanut butter, sorghum malt and duckling mash are presented illustrating the value of the procedure for confirming the presence of aflatoxins B₁ and G₁.     

A Study On Air Pollution by Asphalt Fumes

Abstract

A TLC/HPLC procedure for the determination of polycyclic aromatic hydrocarbons (PAH), occuring in asphalt fumes (adsorbed on particular matter), is described. The method is based on extraction of asphalt fume particles, collected on glass fibre filters, using CCK₄. Following a clean up step by the aid of a TLC procedure on Al₂ O₃ thinlayer plates, using a mixture of cyclohexane/acetone/ether as the mobile phase. Under UV-light, occuring PAH are indicated as fluorescent spots. A separation of the collected PAH into individual components and their identification is performed by the aid of a HPLC procedure. Futher-more, an approach was made to verify the separated PAH by their fluorescence spectra and their mass spectra.     

Quantitation of Creatinine in Urine and Plasma Samples by Reversed Phase HPLC

Abstract

Creatinine determination in urine and plasma affords an index of the renal function. Reversed-phase high pressure liquid chromatography was used for the separation and quantitation of creatinine in normal and arsenic exposed human urine samples. Acetonitrile/water (1:1) was the mobile phase. The method was compared with the Jaffé alkaline picrate reaction. Results show that the HPLC procedure has high reproducibility and samples are stable at the storage conditions. Plasma samples required depro-teinization and extraction with CH₃CN prior to HPLC analysis, while urine samples required only centrifugation.     

An Accurate,Specific HPLC Method for the Analysis of a Decapeptide in a Lactose Matrix

Abstract

A high-performance liquid chromatographic (HPLC) method is described for the determination of an analog of the hormone LH-RH in lyophilized vials at the low parts-per-million level. The peptide (Schally analog) is quantitatively recovered from the glass lyophilization vials after reconstitution with mobile phase. The peptide solution is eluted on a reversed-phase, C₁₈ column and monitored with ultraviolet (UV) detection at 220 nm. The chromatography resolves Schally analog from a number of synthetic impurities and decomposition products.     

HPLC Analysis of Adriamycine as N-2,4-Dinitrophenyladriamycine

Abstract

Derivatization of adriamycine (I) by reaction with 2,4-dinitrofluorobenzene, followed by HPLC analysis on reversed phase (RP-18 μ-Bondapak) or on normal phase (μ-porasil) and detection at 482 nm, provides a fast method (R_f=4.0 min) for determination of adriamycine [as N-2,4-dinitrophenyladriamycine (III)] in the 1–10 ppm range. Reaction with 2,4-dinitrofluoro[^?14C]benzene, followed by HPLC separation and detection on a γ counter, extends the detection limit to 0.04 ppm adriamycine.     

High Performance Liquid Chromatographic Separation of Bacitracin Methylenedisalicylate

Abstract

Our previously described isocratic RP HPLC procedure was convenient for monitoring and quality control of bacitracin production and Zn - bacitracin feed grade preparations. Separation and quantitative determination of the main active bacitracin components (A₁ B₁ and B₂) are possible and those elution is not interrupted by other ingredients in this type of samples. But when the methylenedisalicylic salt of bacitracin was tested some modification of method were necessary for the correct separation of bacitracin components. Mobile phase had to be modified and polystyrene based packing was an alternative and useful complement to octadecylated silica gel packings.     

Determination of Zero Retention Times (t0) by Temperature Dependent Reversed Phase High Perfomance Liquid Chromatography

Abstract

For a given reversed phase HPLC system the zero retention time (t₀) can be determined by measuring brutto retention times at different temperatures. For calculation of t₀ value temperature intervals must be equidistant in 1/T. If at least two compounds are separated on the column having almost the same sorption enthalpies a more simple intersecting point method can be practised. In this case only two temperature points are necessary for graphic evaluation. The presented methods for determination of t₀ values are proved for noradrenaline and adrenaline under selected experimental conditions using aqueous solutions of alkaline perchlorates as mobile phases. Thus t₀ values can be determined with an accuracy and a precision of less than ± 3%.     

HPLC‐UV Detection for Analysis of p‐Benzoquinone Dioxime and p‐Nitrosophenol,and Chromatographic Fingerprint Applied in Quality Control of Industrial p‐Benzoquinone Dioxime

Abstract

A reliable reversed‐phase high performance liquid chromatographic (HPLC) method has been developed for simultaneous determination of p‐benzoquinone dioxime (BQD) and its related impurity p‐nitrosophenol (NSP). Separation was achieved on a Kromasil C₁₈ column by using methanol‐water‐NH₄Ac‐NH₃ solution (pH=7.0, 50 mM) (30/50/20, v/v/v) as the mobile phase, and detection was operated by UV absorption at a wavelength of 305 nm. The method was seen to have good linearity, accuracy, and precision for the concentration range and to be an attractive choice for the quality control of BQD for industrial use. Moreover, the HPLC‐UV‐vis fingerprint of BQD has been established, and successfully applied to quality control of industrial BQD in laboratories of some rubber factories in China. Chromatographic fingerprints of intermediates would become an effective strategy for accelerating the progress of fine chemical industry.     

A Rapid Method For Cyclosporine A Determination By Hplc

Abstract

A rapid method is described for the determination of cyclo-sporine in whole blood by HPLC. The cyclosporine is extracted with an acetonitrile-isopropanol mixture, purified on a C₁₈ minicolumn, and finally injected on a CN column. Recovery of the drug is greater than 90%.     

High Pressure Liquid Chromatographic Determination of Isoniazid and Acetylisoniazid in Human Plasma

Abstract

A quantitative high pressure liquid chromatographic (HPLC) assay has been developed for the determination of isoniazid (INH) and acetylisoniazid (ACINH) in human plasma. Plasma samples were taken from a patient after oral administration of INH (with proven tuberculosis infection). A C₁₈ reversed phase radial compression column was used to separate INH and ACINH from other plasma components. The analysis takes 10 minutes per sample and the lower limit of detection for each compound is 0.10 ug/ml plasma.     

High Performance Liquid Chromatograph 1C Method for Determination of Mifobate in Rat Feed

Abstract

A high performance liquid Chromatographie (HPLC) method is described for the quantitative determination of Mifobate (SR-202) in rat feed. Mifobate is extracted in acetone and isolated from other extractants on a Waters Sep-pak® C₁₈ disposable pre-column. The extracted drug and internal standard are chromatographed on a μBondapak? C₁₈ reverse phase column with a mobile phase consisting of water and acetonitrile (55:45, v/v). The eluent is monitored at 225 nm.

The method provided a 101.56 ± 5.1% mean recovery of Mifobate from spiked feed samples ranging in the 22.24 to 433.04 mg/kg concentration range. Standard curves bracketing this concentration range had linear coefficients greater than 0.9998. The average relative standard deviation (%) for the entire concentration range was 4.2%. The critical steps and precision of the method were also evaluated.     

Measurement of Nicotine in Plasma by High-Performance Liquid Chromatography

Abstract

A new procedure has been developed to measure nicotine in blood plasma by high-performance liquid chromatography (HPLC). Nicotine is extracted from plasma by elution with cholorform. Final determination is achieved by isocratic HPLC with ultraviolet detection. Twenty microliters of plasma extract is deluted over a silica column at a flow rate of 1.0 ml/min with a dioxane:isopropanol:NH₄OH (80:3.0:0.4) mobile phase. The procedure is sensitive to 0.05 ug of nicotine per ml of plasma and is linear within the range of 0.05 to 10.0 ug/ml of plasma. When a known amount of nicotine was added to plasma, the concentration of nicotine measured averaged 99.9 + 3.9 (S.D.)% of the known concentration. The within-sample coefficient of variation was 3.9%     

The Analysis of Sulphonamide Drug Residues in Pork Muscle using Automated Dialysis

ABSTRACT

The aim of this study was to assess the suitability of automated dialysis, using a commercial system, for the analysis of sulphonamides in porcine tissue. The system involves automated dialysis, followed by trace enrichment of the dialysate prior to HPLC determination. The procedure was applied to the analysis of nine sulphonamide drug residues using reversed phase HPLC as the method of determination. Muscle samples were blended in saline, centrifuged and the supernatant was filtered before dialysis for an optimised time of 11 min. The resulting dialysate was concentrated on a reversed phase trace enrichment cartridge prior to HPLC analysis with UV detection at 280 nm. The developed method was evaluated by carrying out intra- and inter-assays on fortified porcine muscle. Mean recoveries, evaluated from the inter-assay study, were 80% or higher for the nine sulphonamides studied and the limit of determination for the method was 40 ng g^?1.     

A Bidimensional HPLC System for Direct Determination of Theophylline in Serum

Abstract

A bidimensional HPLC system combining steric gel exclusion and reverse phase ODS columns for determination of theophylline in serum is reported. Factors involved in the development of the method and its performance are discussed. This technique is a practical alternative for the determination of theophylline levels in serum without any clean up procedure before chromatography.     

High-Performance Liquid Chromatography of Domoic Acid,a Marine Neurotoxin,with Application to Shellfish and Plankton

Abstract

A recent outbreak of poisoning resulting from the consumption of cultured blue mussels (Mytilus edulis L.) from a localized area in Eastern Canada has been attributed to the presence of domoic acid (1), a relatively rare neurotoxic amino acid, previously found only in some algae of the family Rhodomelaceae. Studies on aqueous extracts of shellfish tissue indicated that the toxin and several of its isomers could be separated (and isolated in sufficient amounts for subsequent structural identification) by reversed-phase high-performance liquid chromatography (HPLC) with ultraviolet (UV) diode array detection (DAD). Aqueous acetonitrile containing 0.1% v/v trifluoroacetic acid was used as mobile phase. As the retention time and characteristic UV absorption spectrum of 1 (λ_max = 242 nm) permit unequivocal identification, the HPLC-DAD procedure was refined with a microbore column to provide a rapid (5 min), sensitive (0.3 ng detection limit) and reproducible assay method for the determination of 1 in shellfish tissue. Extraction was accomplished by boiling homogenized shellfish tissue for 5 min with distilled water. Extracts were taken through an octadecylsilica solid phase extraction clean-up prior to HPLC. This method has been applied to a variety of shellfish and phytoplankton samples.

BRIEF

Reversed-phase HPLC with ultraviolet diode array detection was used to analyze shellfish tissue and phytoplankton extracts for domoic acid. A rapid (5 min) and sensitive (0.3 ng detection limit) assay is presented.