Reduction of chromium(VI) to chromium(Ill) by thiourea between pH 3.0 and 5.5 is a key aspect of the chrominm(VI)/thiourea/polyacrylamide gel polymer system used in enhanced oil recovery processes. A method has been developed to determine chromium(Vl) concentration during the reduction of chromium(VI) to chromium(III) in this pH range. The reduction reaction is run in the presence of an acetic ...

a thin-layer chromatography method has been developed and evaluated for the separation and determination of lysine and methonine in a mixture of amino acids obtained from acid or enzyme hydrolysis of protein. the solvent systems were (a) ethanol-ether, (b) phenol-water, (c) ethyl methyl ketone-pyridine-distilled water-glacial acetic acid. procedures in all the three stages were in the same dime...

The data on the standards for chromium requirements and the safety of various chromium compounds and doses are reviewed. The 350-fold difference between the acceptable daily intake and the calculated reference dose for humans of 70 mg per day seems without precedent with respect to other nutritional minerals. Previous claims of mutagenic effects of chromium are of questionable relevance. While ...

in order to investigate effect of methionine levels in starter diet on performance, immunity and blood parameter of arian broilers chickens during the starter period, a trial with 700 broiler chickens in a completely randomized design with 7 treatments, 5 replicates and 20 chicks in each experimental unit was performed. experimental groups were consisted of 0.38, 0.43, 0.48, 0.53, 0.58, 0.63 an...

the purpose of this study was to investigate the effect of feeding dietary soy protein and soy protein supplemented with methionine on lipids and lipoproteins content of blood in wistar rats. sixteen male and 16 female wistar rats with the initial live weight of 116 ± 6.3 and 115.8 ± 6.8 grams respectively, were fed by the isocaloric and isonitrogenous diets containing casein (20%), soy protein...

This study was undertaken to develop an assay for biologically active chromium suitable for determining the best form of chromium for human supplementation studies. The assay involved monitoring the decrease in fasting serum glucose for 1-3 hours in normal human subjects following ingestion of 100 μg of chromium. The maximum decline occurred 1-2 hours after taking the chromium. The average maxi...

BACKGROUND:Herbal methionine can be compared relative toDl-methionine with evaluation of bioavailability of this source ofmethionine. OBJECTIVES: An experiment was carried out todetermine the relative bioefficacy of herbal methionine (H-Met)®relative to DL-methionine (DL-Met) on performance criteria andimmunocompetence of Met sources in male broilers. Atotal of 160male broilers were fed a Met-d...

The essentiality and carcinogenicity of chromium depend on its chemical form. Oxidation state and solubility are particularly important in determining the biological effects of chromium compounds. For this reason, total chromium measurements are of little value in assessing its nutritional benefits or its toxicological hazards. Aqueous sodium carbonate-sodium hydroxide solutions have been succe...

Two workers exposed to trivalent chromium sulphate in a leather tannery had high concentrations of chromium in the urine. The concentration of chromium showed a workshift-related diurnal fluctuation, but it was remarkably high even after a vacation, indicating accumulation of chromium in the body. The concentrations of chromium in the workplace air, as collected on filters using standard techni...

Chromium exists primarily in two forms: trivalent and hexavalent. Trivalent chromium is present in the cationic form as Cr+3 and is an essential nutrient, but hexavalent chromium is toxic and exists as an anion, either as chromate (CrO4 -2) or dichromate (Cr2O7 -2). Therefore, the analysis of total chromium does not always provide a true indication of the effects of chromium present in a sample...