The determination of chromium in biological materials by atomic absorption spectroscopy

Cytotoxic and clastogenic effects of soluble and insoluble compounds containing hexavalent and trivalent chromium

“…Only Cr(VI) reduction within the cell nucleus, and then only in the cells of target organs, could produce the interaction of Cr(III) with biological molecules relevant for the expression of carcinogenic effects. It is generally assumed that Cr exists within cells only in its reduced form, and Cr(III) is indeed detected, even after treatment with Cr(VI) compounds, by colorimetry (Levis et al, 1978a, b; and in the present data), atomic absorption spectrophotometry (Feldman et al, 1967) and gas chromatography (Savory et al, 1970). All these procedures, however, require wet decomposition of the biological samples with acidic mixtures which, in our experience, produce significant reduction of Cr(VI) to Cr(III) (see Methods).…”

“…Standard calibration curves, made with potassium dichromate and chromium chloride as highly soluble Cr(VI) and Cr(III) salts, gave reliable results for the direct Cr(VI) determination by DPCA in Hanks' balanced salt solution (HBSS) and MEM, provided that phenol red was not added to the solutions as an indicator of pH, as well as for total Cr determination (Cr(VI) + Cr(IJJ)) in HBSS, MEM and treated cells, after wet decomposition of the samples by mineralization at 180NC for 2-3 h with nitric acid: sulphuric acid: perchloric acid (3:1:1) and oxidation with potassium permanganate. The last procedure has been used also for Cr(VI) and Cr(III) determination in biological samples both by atomic absorption spectrophotometry (Feldman et al, 1967) and gas chromatography (Savory et al, 1970) Tables I, IV, V), Cr compounds were directly suspended in the growth medium used for treatments. In the experiments on the induction of chromosome aberrations and SCE in CHO cells, almost complete solubilization was obtained in N HCI for Cr(III) compounds and 0-5N NaOH for Cr(VI) compounds, after which they were diluted with MEM to the final concentrations specified in Table IX (Maltoni, 1976) and mutagenicity in bacteria (Petrilli & de Flora, 1978a,b;de Flora, 1981 Tables IV, V, VII and Fig.…”

Cytotoxic Effects of Hexavalent and Trivalent Chromium on Mammalian Cells In Vitro

“…On the basis of colorimetric Cr determinations (Tables IV-V) as well as of the much more sensitive atomic absorption spectrophotometry (Feldman et al, 1967), only Cr3+ is detected inside the cells even after treatment with K2Cr2O7, and its level increases with the exposure period and K2Cr2O7 concentration, reaching a maximal value of about 5 x 10-2 2ug…”

The distribution of heavy metals in the red abalone,Haliotis rufescens, on the California coast

“…Procedures described by Berman (1965, 1967), Fuwa et al (1964), Feldman et al (1967, Hannig andAprison (1967), andParker et al (1967) for the determination of Cd, Cu, Cr, Zn and other metals in biological samples were utilized in conjunction with empirically determined procedures developed at the Hopkins Marine Station of Stanford University. Duplicate and sometimes triplicate one-g aliquots of powdered sample were placed in 30-ml Pyrex beakers and five ml of 70% redistilled nitric acid was added.…”