Development of a Solid - Phase System for the Extraction of Diazinon from Water

Abstract

A selected sorbent granulated activated charcoal solid - phase extraction was developed and used to extract diazinon from distilled water (TDW), distilled deionized water (DDW) and stream water (DW) was studied in the laboratory. Prior to the extraction, the half-live of the diazinon was determined in buffer solutions of pH 6, 7 and 8. The study showed that the half-lives were found to be 0.074, 0.022 and 0.077 hours respectively. Aqueous solution of diazinon was extracted in triplicate from distilled water, deionized distilled water and stream water using SPE systems. The extracted analyte was analysed by uv-visible spectrophotometer. The mean percentage recovery from distilled water, deionized distilled water and stream water using SPE 88.58%, 78.74% ad was 67.85% respectively while diazinon recovery using Liquid-liquid Extraction techniques gave a mean percent recovery of  96.60%, 93.80% and 75.54% for DW, DDW ad SW respectively. The mean percent analyte loss for SPE systems was 32.79%. The value was approximately twice higher than those obtained from LLE techniques with a value of 14.16%. The mean percentage recovery and analyte loss for SPE and LLE were compared. Similarly, the second order rate constant of diazinon of  pH6, 7 and 8 were 2.6 x 10-3, 8.8 x10-3 ad 2.5 x 10-3 M-1S-1respectively. The study suggests that granulated activated charcoal can be used as an sorbent to extract diazinon from water.