We used a special-purpose glass microfiber sample, Johns-Manville Code 100/475, to study the effects of various acid and alkali treatments on biological activity as assessed by inflammation in the mouse peritoneal cavity, the leaching of Si, and the phase contrast optical microscopy (PCOM) fiber number. We used mild and medium treatments with oxalic acid and Tris buffer and harsh treatment with...

Large quantities of oxalic acid accumulate in the cell sap of various plants and as a major product of carbohydrate metabolism by many molds. A recent investigation in our laboratory revealed that oxalic acid was produced from oxalacetic acid by an enzyme system which was isolated from the mycelia of Aspergillus niger (1). It was also demonstrated that oxalic acid was converted to formic acid a...

Natural estrogens, such as 17beta-estradiol (E2), are the main substances responsible for estrogenic activity found in domestic sewage. In the work described herein, the degradation of E2 has been investigated by single ozonation and catalytic ozonation in the presence of manganese ion (Mn2+) and oxalic acid. The presence of Mn2+ and oxalic acid in the ozonation processes significantly improved...

It is known that oxalic acid is a product of ascorbic acid metabolism in the guinea pig (1) and rat (2), and is formed in man from unidentified precursors (3). Oxalates are also of interest because of their occasional toxicity and unexplained deposition. Ascorbic, dehydroascorbic, and 2,3diketogulonic acids are known to give rise to oxalic and threonic acids in approximately quantitative yields...

Aspergillus niger has shown production of metal chelating compounds mainly oxalic acid and citric acid. Production of oxalic acid by Aspergillus niger was found maximum in presence of Pb, followed by Cu+Pb and Cu. With increase in concentration of Pb to 50, 100 and 250 mg/L, the production of oxalic acid was increased. Whereas increase in concentration of Cu+Pb and Cu, resulted in decreased pro...

1. As varying amounts of calcium oxalate may be held in solution in the urine, conclusions based upon the presence or number of calcium oxalate crystals found therein are of no real value as an indication of the quantity of oxalic acid present. 2. Unless the utmost care is exercised, the results obtained by quantitative estimation of oxalic acid are subject to large percentages of error. This i...

l-Ascorbic acid functions as a precursor of oxalic acid in several oxalate-accumulating plants. The present study extends this observation to include Rumex crispus L. (curly dock), Amaranthus retroflexus L. (red root pigweed), Chenopodium album L. (lamb's-quarters), Beta vulgaris L. (sugar beet), Halogeton glomeratus M. Bieb. (halogeton), and Rheum rhabarbarum L. (rhubarb). Several species with...