Oxytetracycline (OXY) is a broad-range antimicrobial routinely used in pig production, at doses in the range of few g/kg of medicated feed, during the weaning period. It could persist at ppm level in pig liquid manure that routinely is used for organic fertilisation. In the present work we describe a methodology to study OXY environmental fate in arable land where crops are cultivated for anima...

Purpose: To investigate the effect of β-glucuronidase on the extraction efficiency of silymarin (mainly as silybin) from spiked human plasma using a sensitive and reproducible high performance liquid chromatography (HPLC) method. Methods: The importance of β-glucuronidase was evaluated by comparing the extraction efficiency of silymarin in β-glucuronidase-treated and untreated plasma samples. I...

Choline was isolated from deproteinized plasma by cation-exchange chromatography. Isolated choline was directly converted to the 3,5-dinitrobenzoate derivative and was analyzed by paired-ion high-performance liquid chromatography with UV detection at 254 nm. An internal standard, 3-hydroxy-N,N,N-trimethylpropanaminium iodide was used for quantitation of plasma choline. Linearity was achieved fr...

Cilostazol is a selective inhibitor of type 3 phosphodiesterase. 5-(3-Chloropropyl)-1-cyclohexyl-1H-tetrazole, used as an intermediate in the synthesis of cilostazol, has a primary alkyl chloride group, a well-known alerting function for genotoxic activity. Upon request from a regulatory agency, a limit test in accordance with ICH Q2(R1) added with the accuracy of a recovery test of 5-(4-chloro...

gamma-aminobutyric acid is the main inhibitory amino acid neurotransmitter in several areas of the brain. measurement of gamma-aminobutyric acid in the brain will help elucidate its metabolic rote and diagnostic value. the liquid chromatography (lc) system consisted of a delivery pump. male rats (150-250g) were used in this study. the brain was rapidly removed from decapitated animals. trie chr...

High-performance capillary electrophoresis (HPCE) with UV absorbance detection (254 nm) has been applied for analyzing intracellular free ribonucleotides. The nucleotide profiles obtained from peripheral blood lymphocytes differ from those obtained from Molt4 human leukemic cells. With a 140 mM borate buffer, pH 9.4, a nearly complete profile can be obtained in 25 min. HPCE has comparable resol...

objective(s):the present study reports the development and validation of a sensitive and rapid extraction method beside high performance liquid chromatographic method for the determination of crocetin in human serum. materials and methods:the hplc method was carried out by using a c18 reversed-phase column and a mobile phase composed of methanol/water/acetic acid (85:14.5:0.5 v/v/v) at the flow...

A high-performance liquid chromatography (HPLC) method for the determination of azadirachtin (A and B) residues in bovine muscle has been developed. Azadirachtin is a neutral triterpene and chemotherapeutic agent effective in controlling some pest flies in horses, stables, horns and fruit. The actual HPLC method uses an isocratic elution and UV detection. Liquid-liquid extraction and solid-phas...

Background and Objectives: Furfural (F) and hydroxymethyl furfural (HMF) are cyclic aldehydes, which are formed during the heat processing of foods. These chemical contaminants have received much attention due to their suspected health hazards and heat damage indicators. The aim of the present study was extraction and determination of F and HMF in baby-foods using dispersive liquid-liquid micro...

Theobromine and its related compounds, such as caffeine and theophylline, are secondary metabolites that belong to the alkaloids and have economic and cultural importance. These alkaloids have demonstrated stimulatory effects on the central nervous, gastrointestinal, cardiovascular, renal and respiratory systems, resulting in 'energy arousal', increased motivation to work, increased alertness a...