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William L. Lamar

Publications and source records attributed to William L. Lamar.

5 recordsLinked to original sources
USGS2014

Salinity of the lower Savannah River in relation to stream‐flow and tidal action

In order to obtain information needed in planning for industrial development along the Savannah River and in the city of Savannah, Georgia, a study of the salinity of the Savannah River was undertaken by the Geological Survey, United States Department of the Interior, in cooperation with the Georgia Division of Mines, Mining, and Geology. The Works Progress Administration of Georgia and the city of Savannah also cooperated in the study. The Savannah River lies on the boundary between the States of Georgia and South Carolina. The River proper from the mouth to the junction of the Tugaloo and Senaca rivers is 314 miles in length. The area of its watershed is about 10,579 square miles, of which 9,850 square miles are above the stream‐flow gaging‐station near Clyo, Georgia. The River is tidal for about 50 miles above its mouth. The average streamflow for the Savannah River near Clyo, Georgia, was 10,410 and 10,820 second‐feet, respectively, for the years ending September 30, 1938 and 1939. The city of Savannah, Georgia, located on the Savannah River 17 miles above its mouth, is an important seaport and industrial center. The lower Savannah River near the city of Savannah is shown in Figure 1.

Georgia, South Carolina↗
USGS1967

Determination of phenoxy acid herbicides in water by electron-capture and microcoulometric gas chromatography

A sensitive gas chromatographic method using microcoulometric titration and electron-capture detection for the analysis of 2,4-D, silvex, 2,4,5-T, and other phenoxy acid herbicides in water is described. The herbicides are extracted from unfiltered water samples (800-1,000 ml) by use of ethyl ether ; then the herbicides are concentrated and esterilied. To allow the analyst a choice, two esterilication procedures--using either boron trifluoride-methanol or diazomethane--are evaluated. Microcoulometric gas chromatography is specific for the detection of halogenated compounds such as the phenoxy acid herbicides whereas it does not respond to nonhalogenated components. Microcoulometric gas chromatography requires care and patience. It is not convenient for rapid screening of l-liter samples that contain less than 1 microgram of the herbicide. Although electroncapture gas chromatography is less selective and more critically affected by interfering substances, it is, nevertheless, convenient and more sensitive than microcoulometric gas chromatography. Two different liquid phases are used in the gas chromatographic columns--DC-200 silicone in one column and QF-1 silicone in the other. The performance of both columns is improved by the addition of Carbowax 20M. The Gas Chrom Q support is coated with the liquid phases by the 'frontal-analysis' technique. The practical lower limits for measurement of the phenoxy acid herbicides in water primarily depend upon the sample size, interferences present, anal instrumentation used. With l-liter samples of water, the practical lower limits of measurement are 10 ppt (parts per trillion) for 2,4-D and 2 ppt for silvex and 2,4,5-T when electron-capture detection is used, and approximately 20 ppt for each herbicide when analyzed by microcoulometric-titration gas chromatography. Recoveries of the herbicides immediately after addition to unfiltered water samples averaged 92 percent for 2,4-D, 90 percent for silvex, and 98 percent for 2,4,5-T. Studies on the stability of herbicides added to water samples showed that 2,4-D may be rapidly degraded, especially if the samples are obtained from areas which have been repeatedly sprayed with 2,4-D. When degradation was observed, added 2,4-D rapidly decomposed within 10 days. At concentrations of about 200 ppt, however, the degradation rate was diminished. In 20 days the concentration of 2,4-D was reduced to 160-180 ppt.

Water Supply Paper↗
USGS1965

Identification and measurement of chlorinated organic pesticides in water by electron-capture gas chromatography

Pesticides, in minute quantities, may affect the regimen of streams, and because they may concentrate in sediments, aquatic organisms, and edible aquatic foods, their detection and their measurement in the parts-per-trillion range are considered essential. In 1964 the U.S. Geological Survey at Menlo Park, Calif., began research on methods for monitoring pesticides in water. Two systems were selected--electron-capture gas chromatography and microcoulometric-titration gas chromatography. Studies on these systems are now in progress. This report provides current information on the development and application of an electron-capture gas chromatographic procedure. This method is a convenient and extremely sensitive procedure for the detection and measurement of organic pesticides having high electron affinities, notably the chlorinated organic pesticides. The electron-affinity detector is extremely sensitive to these substances but it is not as sensitive to many other compounds. By this method, the chlorinated organic pesticide may be determined on a sample of convenient size in concentrations as low as the parts-per-trillion range. To insure greater accuracy in the identifications, the pesticides reported were separated and identified by their retention times on two different types of gas chromatographic columns.

Water Supply Paper↗