4. UV analysis
After the SWE process, similar to the procedure described in
Section 2.2, to determine the remained solute on the soil, 5 g remediated
soil was placed in a 100 mL beaker and mixed with 60 mL
of methanol and the aforementioned extraction and filtration were
implemented. To make sure that methanol extraction was complete,
extraction was repeated using 25 mL more methanol. The
results showed that the obtained solution in the first step was suitable
for UV analysis and no more solute detected in the second
methanol solution. The quantification of target contaminants of all
extracts was analyzed using UV/Visible Spectrophotometer with
UV300nm (PerkinElmer, Lambda 25, USA)