CONTENTS Arsonic acids

Nitro-4-hydroxyphenyl-arsonic acid At 18.7 mg/kg diet for 9 weeks, liver residues of 2.4 mg/kg FW. Those fed diets containing 187 mg/kg for 9 weeks had no ill effects liver content of 7.5 mg/kg FW 5... 

This compd is probably expl, yet not reported as such. Its methyl deriv is ex pi although its NOj-nitrogen content is smaller (See 3i5-Dinitro-4-methyl ami nophenyl arsonic Acid under Methyl ami no phenyl-arsonic Acid)... 

Finally, particular chemical species can be determined in some cases, as when arsenic content is separated into As(III), As(V), monomethyl arsonic acid, and dimethyl arsinic acid using ion-exchange chromatography. Chemical speciation is sometimes possible but is often very difficult. If the metals... 

Sorption of monomethyl arsonic acid (MMAA), dimethyl arsinic acid (DMAA), and arsenate on anaerobic bottom sediments from the Menominee River, Wisconsin are described by Langmuir Isotherms. These results were Incorporated Into a kinetic model of arsenic species transforamtlon which takes sorption Into account. Model predictions were found to be sensitive to the sediment water content and r, the adsorptive capacity of the sediment. Demethylatlon of MMAA and DMAA was observed In sediment Incubation experiments. The predictions of the sorption/kinetic model were In good agreement with the results of the Incubation experiments. 

Tin (IV) reacts with nitrophenol arsonic acid (3-nitro-4-hydroxyphenyl arsonic acid-2-nitrophenol arsonic acid-(4)) in sulphuric acid solution to produce a constant turbidity which is proportional to the tin content and can be measured photometrically at 436 nm. For determination purposes the tin must be present in the quadrivalent form. 

Treatment of the 8elenlum(IV) polymer with 30% H2O2 results In rapid loss of the color, presumably due to formation of the peracldi In a trlphase system at room temperature 1.5 mol X of the polymer and 1.5 - 1.8 equivalents of H2O2 were effective for oxidation of both olefins and ketones. Unlike the arsonated system, olefins opened readily to the trans dlols only In the case of tetramethylethylene could the epoxide be Isolated. Such a result may be due to partial oxidation to the selenonlc acid, a more powerful acid, or to a more aqueous microenvironment. The Baeyer-Vllllger reactions of ketones could be carried out In a similar fashion In a trlphase system some ester hydrolysis could be observed. Water soluble ketones and aromatic ketones were both unreactlve. The polymer can be recycled readily but becomes unstable If elevated temperatures are used In the reaction. Use of the catalyst under reaction conditions for 150h led to loss of less than 5% of the Initial selenium content. 

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