A sensitive and selective procedure is presented for the voltammetric determination of cobalt. The procedure involves an adsorptive accumulation of cobalt Pyrogallol Red (PGR) complex on a stationary mercury drop electrode, followed by cathodic stripping voltammetry measurement of the reduction current of the adsorbed complex at –1.17 V (vs. Ag/AgCl). The optimum conditions for the determinatio...

A selective spectrophotometric method has been developed for the determination of cobalt after extraction of its 2-methoxyethyl xanthate complex into molten naphthalene. Cobalt reacts with this xanthate in the ratio of 1 : 2 (metal : ligand ratio) in a pH range of 3.5-9.2 and over an acid range of 2.5-7.0 M. It absorbs strongly at 355 nm. Beer's law is obeyed over the concentration range of 2.5...

This paper focuses on how the surface chemical groups of sheep manure affect the adsorption capacity of cobalt ions. Improvement in cobalt ions uptake onto sheep manure was achieved successfully by introducing more carboxylic functional groups into its surface due to citric acid treatment. According to Langmuir model, cobalt ions uptake was increased from 22.88 mg/g for dried sheep manure (D-SM...

Cobalt chloride administration to rats stimulates erythropoesis but inhibits the synthesis of hepatic microsomal P-450 and ethylmorphine N-dealkylase activity by hepatic microsomes. No effect on NADPHcytochrome c reductase activity was observed. Phenobarbital induction of P-450 and ethylmorphine N-demethylation are prevented by simultaneous administration of cobalt chloride but phenobarbital in...

Assimilation of ionic cobalt by axenic cultures of four species of anaerobic rumen bacteria was measured using 6oCo as cobalt (II) chloride. Uptake could be measured in all four species but may not represent active accumulation in the case of Lactobacillus casei and Propionibacterium acnes. Significant uptake (89.5% of 6oCo present) was demonstrated by Selenomonas ruminantium from media contain...

All chambers of the heart are affected in experimental cobalt cardiomyopathy, with atrial predilection. The primary morphological alteration is mitochondrial damage that possibly reflects an enzymatic block of oxidative decarboxylation at pyruvate and ketogluterate levels. In acute cobalt toxicity chelation of calcium may also be a contributory factor, resulting in deficient utilization of high...

Nickel and cobalt are often responsible for metal-induced allergic contact dermatitis. With the increasing use of cell phones, we observed an increase in cases reports on telephone-related allergic contact dermatitis. The present study evaluated nickel and cobalt release from mobile phones used in Brazil. We evaluated devices of 6 brands and 20 different models using nickel and cobalt allergy s...

Alpha-benzilmonoxime in sodium dodecylsulfate micellar media has been used for the spectrophotometric determination of cobalt at pH 9.0. The linear range of calibration is 0.05-1.50 microg cm(-3) of cobalt at 380 nm with molar absorptivity of 3.72 x 10(4) dm3 mol(-1) cm(-1), which is about 1.5-times greater than that of the alpha-benzilmonoxime extraction based method. The relative standard dev...

The current study was designed to investigate the mechanical response of a polyetheretherketone-on-polyethylene total knee replacement device during a deep squat. Application of this high-demand loading condition can identify weaknesses of the polyetheretherketone relative to cobalt-chromium. This study investigated whether the implant is strong enough for this type of loading, whether cement s...