4. Conclusions
This study demonstrates for the first time that direct extraction
of soil sample using -SPE-HPLC is capable of providing better measurement
precision (4–12%) and good relative recoveries (>90%)
in the determinations of carbamate pesticides. Comparison of EPA
Methods 8318 and 8321A procedures with the newly developed
procedure shows the suitability of the microextraction technique
for the detection of trace concentrations of these analytes in soil
samples. -SPE offers more versatile approaches in analyte enrichment
together with simultaneous cleanup. The procedure is easy to
use, and involves less labour and time. The method can be applied
to the routine analysis of real soil samples, as demonstrated in this
work.