2.4. Sample extraction
The extraction was performed in order to segregate targeted
compounds from wastewater and sludge samples. Chloroform was
selected as the final extractant based on its performance among the
initially chosen di-ethyl ether, n-hexane and chloroform. To 100 mL
filtered wastewater sample, 50 mL chloroform was added thrice
and the extracts were combined and evaporated. Finally the residue
was dissolved in 2 mL of methanol and then stored in refrigerator
till HPLC analysis. For extraction of sludge samples, 10 g of sludge
sample was extracted thrice with chloroform, filtered, evaporated,
dissolved in 2 mL methanol and then preserved in refrigerator till
HPLC analyses.