Determination of residues of the butyl ester of 2,4-dichlorophenoxyacetic acid in environmental objects by gas-liquid chromatography
Vasiagina, R.D.; Chmil', V.D.
Gigiena i Sanitariia 38(5): 69-72
1973
ISSN/ISBN: 0016-9900 PMID: 4769799 Document Number: 67478
A g.l.c. method is described for the quantitative determination of 2,4-D butyl ester in air and water. Air is passed through a series of four n-hexane-filled absorbers at a rate of 1 litre/min for 25-50 min. The sample obtained is concentrated in a rotary evaporator, dried with anhydrous sodium sulphate and combined with 50 mu g of 2,4,5-T methyl ester in n-hexane for chromatographic determination on Chromosorb W. Conditions include nitrogen as carrier gas, a column temperature of 186 deg C and a differential flame ionization detector. The sensitivity of the method is 0.3 mu g/litre. Calibration curves are set up for both 2,4-D butyl ester and 2,4,5-T methyl ester. Water samples are mixed with 2,4,5-T methyl ester and hydrochloric acid and extracted with diethyl ether. The extract is treated with sodium hydroxide solution and anhydrous sodium sulphate prior to chromatographic determination with a sensitivity of 10 mu g/litre. As long as the internal standard is added to the sample prior to extraction, recovery studies are not necessary.