Potassium dichromate

About: Potassium dichromate is a research topic. Over the lifetime, 1430 publications have been published within this topic receiving 18967 citations. The topic is also known as: Potassium dichromate(VI) & Chromium potassium oxide.

Automated analysis of sorbic acid in food products

Abstract: The increasing use of sorbic acid and sorbates has created a need for a rapid, reliable and accurate analytical procedure for the routine analysis of these materials in food products. In this paper is described an automated version of the most popular calorimetric (thiobarbituric acid) method, originally proposed by Schmidt. The procedure uses a gas diffusion membrane in lieu of steam distillation for the separation of sorbic acid from the food samples. The separated acid is cleaved with potassium dichromate in acidic medium to yield an intermediate malon-aldehyde, which in turn, when reacted with thiobarbituric acid, produces a red dye. The absorbance of the red color, measured at 530 nm was proportional to the concentration of the sorbic acid in the sample. This automated procedure is capable of analyzing 30 samples per hour.

Histological study on the possible protective effect of curcumin on potassium dichromate induced hypothyroidism in adult male albino rats

Abstract: Introduction: Potassium dichromate, a widely used heavy metal in several industries induces hypofunction and tissue insult of the thyroid gland via oxidative stress. Curcumin; is a natural commonly used spice has a strong anti-inflammatory and antioxidant properties.Aim of the work: To investigate the possible protective effect of curcumin on the hypothyroidism induced by potassium dichromate in albino rats.Materials and Methods: Thirty- five adult male albino rats were divided into five groups, 15 rats in group I (control) and 5 rats in each of group II, III, IV and V. Group II (curcumin group) received curcumin orally (100 mg /kg/bw) daily for 4 weeks. Group III (potassium dichromate induced hypothyroidism) received i.p injection of potassium dichromate (2 mg/kg/bw) daily for 2 weeks. Group IV (recovery group) received potassium dichromate as group III then left untreated for another 2 weeks. Group V(curcumin and potassium dichromate group) received curcumin concomitant with potassium dichromate as in groups II and III, respectively daily for 2 weeks and only curcumin was continued for another 2 weeks. T3, T4 and TSH were assessed. Thyroid sections were subjected to toluidine blue, H&E, PAS and PCNA immunohistochemical stains. Morphometric and statistical studies were done.Results: Thyroid tissue insult and hypofunction with significantly decreased T3, T4 and increased TSH were detected in group III. Additionally, there was a significant increase in the mean values of follicular cell height, follicular diameter, mean number of PCNA positive nuclei and a significant decrease in the mean value of area percent of colloid versus group I, II and V with non-significant differences versus group IV. In group V, there was an obvious serological and histological improvement compared to group III and IV.Conclusion: Curcumin had protective effect against hypothyroidism and thyroid tissue damage induced by potassium dichromate.

Differentiation of normal human keratinocytes influences hexavalent chromium uptake and distribution and the ability of cells to withstand Cr(VI) cytotoxicity

Abstract: The degree of differentiation of normal human keratinocytes determines the biology of the cells to a large extent. We have previously documented that keratinocytes from different donors differ significantly in their ability to withstand hexavalent chromium [Cr(VI)]-induced cytotoxicity. Several factors may contribute to this differing donor sensitivity to Cr(VI). The aims of this study were to investigate to what extent keratinocyte differentiation might influence Cr(VI) uptake and the ability of cells to withstand Cr(VI)-induced cytotoxicity. Keratinocytes from different donors were cultured under identical conditions and exposed to Cr(VI) (as potassium dichromate) at different points during their maturation process. The degree of differentiation of the cells was assessed using a quantitative assay for involucrin and related to the Cr(VI) cytotoxicity experienced by the cells. Chromium content was measured in whole cell, cytosolic and particulate fractions. While proliferative keratinocytes exposed to Cr(VI) showed a high degree of cytotoxicity to dichromate exposure, the more differentiated cells showed significantly less cytotoxicity but a higher uptake of the metal ion into the cells. The relative percentage of cytosolic chromium was high in the proliferative cells and decreased as the cells matured, suggesting that differentiated cultures were binding most of the chromium to the particulate fraction. Total chromium also increased during differentiation. The use of the channel-blocking agent 4, 4'-diisothiocyanate-2-2'-stilbenedisulphonic acid confirmed the spatial differences of chromium accumulation in the phenotypically different cultures, in that it prevented Cr(VI) entry into the proliferative cells and attenuated dichromate cytotoxicity in these cultures, but had no effect on the Cr(VI) uptake in differentiated cells, nor did it reduce its cytotoxicity. These data support the hypothesis that the upper differentiated layers of the epidermis are able to offer considerable physical protection to the lower proliferative layers from chemical pro-oxidants.

Potential of Live Spirulina platensis on Biosorption of Hexavalent Chromium and Its Conversion to Trivalent Chromium

Abstract: Microalga biomass has been described worldwide according their capacity to realize biosorption of toxic metals. Chromium is one of the most toxic metals that could contaminate superficial and underground water. Considering the importance of Spirulina biomass in production of supplements for humans and for animal feed we assessed the biosorption of hexavalent chromium by living Spirulina platensis and its capacity to convert hexavalent chromium to trivalent chromium, less toxic, through its metabolism during growth. The active biomass was grown in Zarrouk medium diluted to 50% with distilled water, keeping the experiments under controlled conditions of aeration, temperature of 30°C and lighting of 1,800 lux. Hexavalent chromium was added using a potassium dichromate solution in fed-batch mode with the aim of evaluate the effect of several additions contaminant in the kinetic parameters of the culture. Cell growth was affected by the presence of chromium added at the beginning of cultures, and the best grow...