This study evaluated the toxicity of hexavalent and trivalent compounds of chromium to the pacu, Piaractus mesopotamicus, in acute exposures of 96 h through mortality and histopathological responses. Hexavalent potassium dichromate was more toxic than trivalent compounds of chromium chloride, chromium oxide and chromium carbochelate. Sufficient mortalities occurred only with potassium dichromat...

THE writer has previously described [1914] a method for the volumetric estimation of carbon, the essence of which is oxidation by a mixture of phosphoric acid and potassium dichromate and the measurement of the 002 produced. It was shown that where methyl groups are present the substance is not oxidised to carbon dioxide alone but to a mixture of carbon dioxide and acetic acid; for example, lac...

Oxidation–reduction titrations and potentiometric methods provide a convenient experimental means to quantitatively determine compositions of unknown mixtures containing oxidizable/reducible species. Over the past decade, numerous titration methods have appeared in this Journal (1–6) and in standard laboratory manuals (7–10) involving common titrants such as potassium dichromate, iodine, potass...

In this paper, a new method for the determination of cysteine by potassium dichromate spectrophotometry is established. H 2 SO 4 medium, has strong oxidation. Potassium can react with hydrosulfuryl(-SH) in cysteine, which makes fade, and fading degree proportional to amount added. Therefore, content be quantitatively determined determinating decrease value absorbance. The various influencing fa...

Pseudokirchneriella subcapitata is a sickle-shaped freshwater green microalga that is normally found in unicellular form. Currently, it is the best known and most frequently used species of ecotoxicological bioindicator because of its high growth rate and sensitivity to toxicants. However, despite this organism's, our knowledge of its cell biology-for example, the patterns of nuclear and cytopl...

Carthamin, the natural dye of carthamus tinctorius (Golrang) was separated by soxhlet extraction and further purified in good yields. Its mordant dyeing of wool, using potassium dichromate as mordant, showed a high washing fastness (above 4). Mordanting by "sweet chrome", "sour chrome", and "reduced chrome" proved that last one to be superior.