Organic substances in potable water and in its precursor. I. Methods for their determination by gas-liquid chromatography.

This article provides a review of available information on the chemistry, environmental toxicology, and mammalian toxicology of nitrilotriacetic acid (NTA). The ability of NTA to chelate metal ions such as Mg++ and Ca++ into water soluble complexes makes NTA useful as an additive to boiler water, as a builder in laundry detergents, and as a stabilizer in textile, paper, and pulp processing. Environmental fate studies show NTA biodegrades in wastewater treatment plants, in natural waters, and in soils under a wide variety of conditions. Studies on the environmental effects of NTA indicate that no adverse effects occur in treatment plants or receiving waters at anticipated levels. Monitoring programs have established that only low steady-state concentrations of NTA occur in natural waters as a result of NTA usage. In mammalian systems, NTA is not metabolized and is excreted rapidly by filtration in the kidney. No reproductive, teratogenic, or adverse bone effects have been observed at highly exaggerated doses. In numerous genotoxicity assay systems, both in vivo and in vitro, NTA is nongenotoxic. Chronic oral exposure of rodents to high doses of NTA is associated with tumorigenicity in, and restricted to, the urinary tract. The urinary tract tumors are the consequence of chronic toxicity that is caused by changes in Zn and Ca distributions between the urinary tract tissues and urine at high doses of NTA. Thresholds for the effects of NTA on Zn and Ca distributions are 10(5) to 10(6) greater than the possible maximum human exposure resulting from the low levels of NTA that are known to occur in the environment.

A Review of the Environmental and Mammalian Toxicology of Nitrilotriacetic Acid

On the unexpected behavior of a common gas chromatographic phase

Organic substances in potable water and in its precursor

An overview of the methods used for the isolation and characterization of organic matter in natural waters is presented. Commonly used techniques for the concentration and isolation of organic matter from water, such as preparative chromatography, ultrafiltration and reverse osmosis, and the methods used to analyze the organic matter obtained by these methods are reviewed. the development of methods to obtain organic matter that is associated with fractions of the dissolved organic carbon other than humic substances, such as organic bases, hydrophilic organic acids and colloidal organic matter are discussed. Methods specifically used to study dissolved organic nitrogen and dissolved organic phosphorous are also discussed.

Isolation and Chemical Characterization of Dissolved and Colloidal Organic Matter

The determination of part-per-billion levels of citric and nitrilotriacetic acids in tap water and sewage effluents.

The determination of picloram in fescue by gas-liquid chromatography.

A dual-mode indium flame detector

Novel determinations of picloram by gas—liquid chromatography

Gas chromatographic determination of 2-ethylhexanol and 2-ethylhexanoic acid as derivatives suitable for electroncapture and nitrogen-phosphorus detection after single reaction with heptafluorobutyrylimidazole

Robert F. Moseman

Papers

The determination of part-per-billion levels of citric and nitrilotriacetic acids in tap water and sewage effluents.

The determination of picloram in fescue by gas-liquid chromatography.

A dual-mode indium flame detector

Novel determinations of picloram by gas—liquid chromatography

Gas chromatographic determination of 2-ethylhexanol and 2-ethylhexanoic acid as derivatives suitable for electroncapture and nitrogen-phosphorus detection after single reaction with heptafluorobutyrylimidazole