Dm. Goli et al., SUPERCRITICAL-FLUID EXTRACTION FROM SOIL AND HPLC ANALYSIS OF CYANAZINE HERBICIDE, Journal of agricultural and food chemistry, 45(4), 1997, pp. 1244-1250
Efficacy of supercritical fluid extraction (SFE) for the recovery of c
yanazine )-1,3,5-triazin-2-yl]amino]-2-methylpropionitrile) from soil
was investigated. A reverse-phase HPLC method and a TLC method were de
veloped for quantitative separation of cyanazine from its seven metabo
lites. Dundee silty clay loam soil treated with C-14-ring-labeled and
nonlabeled cyanazine was used. Several SFE parameters were optimized f
or maximum recovery of cyanazine. Methanol/water (1:1) added directly
to the soil matrix was the most efficient modifier. Extraction with su
percritical CO2 at a flow rate of 3.0 mL min(-1), a density of 0.90 g
mL(-1), and an extraction temperature of 50 degrees C was optimal. Wit
h 6 and 20 min static and dynamic extraction times, respectively, cyan
azine could be extracted from soil in 40-45 min. With a considerable s
avings in time and lower waste solvent generation, recoveries (>90%) v
ery similar to conventional extraction procedures could be obtained. E
xtraction of some of the cyanazine metabolites from soil, under the co
nditions optimized for cyanazine, was also investigated.