TOXAPHENE DISSIPATION FROM TREATED COTTON FIELD ENVIRONMENTS - COMPONENT RESIDUAL BEHAVIOR ON LEAVES AND IN AIR, SOIL, AND SEDIMENTS DETERMINED BY CAPILLARY GAS-CHROMATOGRAPHY

Residues of toxaphene were analyzed in leaf, air, and top soil samples taken up to 58 days following a commercial application at 9 kg/ha to a San Joaquin Valley, California, cotton field. Analyses were by packed column gas-liquid chromatography (GLC) for total toxaphene residues and by open-tubular (capillary) column GLC for enhanced component resolution. Leaf residues at 50 days following treatment (135 ppm) showed a regular trend toward greater loss of components of higher volatility when compared with the 0-day sample (661 ppm). This was matched by a corresponding enrichment of volatile components in air samples, most noticeable in an early (2-day) sample (1.8 µg|m3) but still evident in a later (14-day) sample (1.9 µg/m3). Vaporization was indicated to be the major route of loss from foliage, with no noticeable role played by chemical decomposition. Decline from aerated top soil (from 13.1 ppm at 0 days to 6.4 ppm at 58 days) was also primarily by vaporization, but at least one component was significantly degraded. Soil core and irrigation ditch residues sampled more than a year after treatment showed extensive toxaphene component degradation, resulting in selective decline of some components. The evidence indicated that anaerobic reduction occurred in these environmental compartments. © 1979, American Chemical Society. All rights reserved.