ISSN:
1432-0703
Source:
Springer Online Journal Archives 1860-2000
Topics:
Energy, Environment Protection, Nuclear Power Engineering
,
Medicine
Notes:
Abstract The combined photolysis-hydrolysis rate of chlorpyrifos in water at 25†C followed simple first-order kinetics at 9 × 10−7M concentration. In buffered, distilled water at pH 5.0, 6.9, and 8.0, the half-life was 11.0, 12.2, and 7.8 days, respectively. The half-life of the isolated photolysis reaction was 13.9, 21.7 and 13.1 days, respectively. Qualitatively, the products of the combined photolysis-hydrolysis reactions with chlorpyrifos wereO-ethylO-(3,5,6-trichloro-2-pyridyl)-phosphorothioate, 3,5,6-trichloro-2-pyridinol, and five radioactive unknowns, one of which was thought to contain H14CO 3 − . Loss rates of chlorpyrifos due to photodecomposition on and volatilization from an inert surface at 25†C were best represented by first-order processes. The half-life for disappearance of chlorpyrifos was 3.2 and 0.3 days, respectively. The results reported herein suggest that on those occasions when chlorpyrifos shows reduced efficacy in the field, volatility loss may be the primary cause. The rates of photolysis and hydrolysis reactions are sufficiently fast that the compound will not persist in bodies of water, nor will the compound present any problems relative to field reentry safety intervals.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01059580
Permalink
