Neat samples of polyunsaturated fatty acids were exposed to ozone in air in a flow system and the formation of peroxides, conjugated dienes and thiobarbituric acid (TBA)-reactive material was followed as a function of time. The effect of ozone is to shorten the induction period normally observed in autoxidation studies, but the ozone, at the concentrations used here (0–1.5 ppm), appears to have no effect on the rates of product formation after the induction period. During the induction period, increasing ozone concentrations give rise to substantially increased rates of peroxide (or materials which titrate like peroxide) formation, a slightly increased rate of conjugated dienes formation, and no significant increase in the rate of production of TBA-reactive material. Vitamin E lengthens the induction period but appears to have no other effect. Some of these data are in conflict with earlier reports of Menzel et al.

Autoxidation of polyunsaturated fatty acids. Part I. Effect of ozone on the autoxidation of neat methyl linoleate and methyl linolenate.

Relationship of manganese-iron oxides and associated heavy metals to grain size in stream sediments

Spectrophotometric method for determination of ozone in aqueous solutions

An examination of the major anthropogenic and natural sources of atmospheric selenium indicates that approximately 13–19×109 g Se are cycled through the troposphere annually. Perhaps 60% of this flux is natural in origin, and both man-made and biological emissions appear to be predominantly gaseous in nature. Emissions from the marine biosphere and the combustion of coal account for 50–65% of the total atmospheric selenium emissions, and the natural marine flux appears to be roughly twice as large as that due to coal combustion.

A global atmospheric selenium budget

Introductory Concepts.- to Environmental Chemistry.- Chemistry Fundamentals, Part A.- Chemistry Fundamentals, Part B.- The Chemistry of Natural Environmental Processes.- The Chemistry of Processes in the Atmosphere.- The Chemistry of Processes in the Lithosphere.- The Chemistry of Processes in the Hydrosphere.- Natural Biochemical Processes and Organisms in the Biosphere.- Effects, Treatment and Prevention of Pollution.- Effects of Pollutants on the Chemistry of the Atmosphere, Hydrosphere, and Lithosphere.- Effects of Pollutants on the Biosphere: Biodegradability, Toxicity, and Risks.- Physicochemical and Physical Treatment of Pollutants and Wastes.- Biological Treatment of Pollutants and Wastes.- The Minimization and Prevention of Pollution Green Chemistry.

Sham L. Sachdev

Papers

Determination of vanadium by atomic absorption spectrophotometry

Effect of mixed organic solvents on atomic absorption spectrophotometry of refractory metals

Specific method for the determination of ozone in the atmosphere.

Concentration and determination of traces of metal ions

Determination of manganese, iron, cobalt and nickel in air and water by atomic absorption spectroscopy