Gas-chromatographic detection of phthalic acid esters.

Each second, the rivers of the world add 109 kg of fresh water to the oceans, and with this water comes tremendous quantities of salts, clay minerals, and other suspended solids. Although the Amazon River makes the largest contribution of fresh water to the sea, its waters are relatively uncontaminated. On the other hand, the Mississippi River, the third largest river, which delivers only about one-twelfth the volume of the Amazon River, flows many hundreds of miles through rich, extensively cultivated farm land and some of the most highly industrialized areas in the world. Thus, in addition to the salts and suspended material normally present in river water, the waters of the Mississippi could conceivably carry agricultural and industrial wastes from land drainage into the Gulf of Mexico. The surface waters and stream bed materials of the Mississippi River and other rivers of the United States have been monitored for a number of years through the coordinated efforts of federal, state, local and private agencies. Green et al (1) summarized the results of these studies on surface waters for the years 1958-1966, while Barthel et al. (2) did much the same for stream-bed material. However, the monitoring program does not follow the river water nor stream bed material out into the Gulf of Mexico. A program of study designed to measure the