A method of supercritical fluid extraction (SFE) of triazine herbicide
s from soil has been developed. The recoveries of triazine herbicides
increased with increase in both extraction pressure and temperature wh
en supercritical carbon dioxide was used as the extraction medium alon
e. Because the recovery by SFE was influenced by the concentration of
triazine herbicides in the soil matrix, the addition of methanol to ca
rbon dioxide as a polar modifier was required for the satisfactory ext
raction of trace levels of the content of the herbicides. The moisture
content of the soil also affected the recoveries by SFE. SFE was appl
ied to the analysis of real samples. The results by SFE were almost th
e same as those from soxhlet extraction.