A highly-sensitive analytical method for the detection of p-hydroxymethamphetamine (pOHMA) in urine is presented. The proposed method combines liquid-liquid extraction with acetonitrile and solid-phase extraction by thin-layer chromatography (TLC) with oxidation using potassium hexacyanoferrate(III) and sodium hydroxide to detect the fluorophor of pOHMA. The detection limit for pOHMA is 10 ng (...

an extensive study of fischer-tropsch synthesis (fts) on alumina-supported cobalt catalysts with different amounts of cobalt is reported. up to 40 wt % of cobalt, is added to the catalysts by impregnation method. the effect of the cobalt loading on the reducibility of the cobalt oxide species, dispersion of the cobalt, average clusters size, water-gas shift (wgs) activity and activity and selec...

BACKGROUND Cobalt has been shown to induce mainly asthma, allergic contact dermatitis and hard metal disease. The data on cobalt asthma are mainly based on case reports. AIMS To characterize all the cases of occupational cobalt asthma encountered in a cobalt plant at the time of diagnosis and 6 months later. We also evaluated the incidence of cobalt asthma in different departments on the basi...

We report a method to control the conformation of a weak polyampholyte (the protein β-casein) in Langmuir monolayers by light, even though the protein is not photosensitive. Our approach is to couple the monolayer state to a photochemical reaction excited in the liquid subphase. The conformational transition of the protein molecule is triggered through its sensitivity to a subphase bulk field (...

Prussian Blue (ferric hexacyanoferrate(II)) was discovered accidentally by Johann Jacob Diesbach (1) and Johann Konrad Dippel (2) in Berlin in 1706 (3). As the first synthetic pigment, Prussian Blue received its name from the country in which its discovery occurred. It revolutionized the use of the color blue in artwork because it was less expensive and/or more stable than other blue pigments o...

We introduce dual kinetic chronoamperometry, in which reciprocal relations are established between the kinetic curves of electrochemical reactions that start from symmetrical initial conditions. We have performed numerical and experimental studies in which the kinetic curves of the electron-transfer processes are analyzed for a reversible first order reaction. Experimental tests were done with ...

A cobalt spot test was recently developed (1). Testing for cobalt release is performed by dipping a white cotton stick into a clear yellow cobalt test solution containing nitroso R salt, followed by rubbing of the cotton stick for 20–30 seconds against the test item. A colour change from yellow to red–orange indicates a positive test reaction. The spot test detects approximately 8 ppm cobalt in...