Different chemical formulations for the synthesis of highly intercalated graphite bisulfate have been tested. In particular, nitric acid, potassium nitrate, potassium dichromate, potassium permanganate, sodium periodate, sodium chlorate, and hydrogen peroxide have been used in this synthesis scheme as the auxiliary reagent (oxidizing agent). In order to evaluate the presence of delamination, an...

BACKGROUND Five workers from a plant manufacturing concrete wall panels and beams were referred to our department because of suspected occupational dermatitis. When patch tested, 3 workers reacted to potassium dichromate. Four workers reacted to ethylenediamine dihydrochloride, without any obvious exposure. Owing to the high proportion of workers with recent-onset skin disease, an investigation...

Disclosed is a method of preparing pigmentary chromium oxide nano particles having 50 percent particle size less than about 100 nm. Preparation of nano chromium (III) oxide is investigated by thermal decomposition method. According to the disclosed method, a substantially dry solid composition of potassium dichromate and carbon active is heated in CO2 atmosphere to a temperature of about 60...

In previous papers (1, 2) it has been shown that in dilute aqueous solutions aldehydes may be oxidized in the a! position by oxidizing agents such as ceric sulfate, potassium dichromate, and potassium ferricyanide. Normal butyraldehyde and isobutyraldehyde yielded the most conclusive results; the latt,er was converted by ceric sulfate at 80’ into cr-hydroxyisobutyraldehyde and acetone. The evol...

BACKGROUND The standardized protocol for performing the strip patch test has proven to be valid, but evidence on its reliability is still missing. OBJECTIVE To estimate the parallel-test reliability of the strip patch test as compared with the conventional patch test. METHODS In this multicentre, prospective, randomized, investigator-blinded reliability study, 132 subjects were enrolled. Si...

BACKGROUND Samples for diagnostic procedures often require some form of pre-analytical preparation for preservation or safe handling during transportation prior to analysis in the laboratory. This is particularly important for milk samples which frequently need preservatives to retain milk composition as close to that found in freshly collected samples as possible. METHODS Milk samples were t...

Common sources of chromium in wastewater are electroplating and leather industries. Hexavalent chromium is more toxic and carcinogenic compared to its trivalent counterpart. Conversion of Cr (VI) to Cr (III) in an aqueous medium both by chemical reduction using zerovalent iron and by photocatalytic reduction using UV radiation and ZnO semiconductor has been investigated using potassium dichroma...

A potentiometric titration method for the determination of minoxidil based on its redox reaction with K2Cr2O7 is described. The best results were observed using 1.00 x 10-3 mol L-1 K2Cr2O7 and 1.00 x 10-2 mol L-1 minoxidil solutions, and the minoxidil as titrant in 2.00 mol L-1 H2SO4 medium. The method was applied to commercial samples and compared with the results from a chromatographic proced...