Solvent-assisted dispersive solid-phase extraction: A sample preparation method for trace detection of diazinon in urine and environmental water samples

• Solvent-assisted dispersive solid phase extraction.
• Low cost and efficient sample preparation method.
• High pre-concentration factor and appropriate method detection limit.
• Diazinon.
• Urine and waste water samples.

In this research, a sample preparation method termed solvent-assisted dispersive solid-phase extraction (SA-DSPE) was applied. The used sample preparation method was based on the dispersion of the sorbent into the aqueous sample to maximize the interaction surface. In this approach, the dispersion of the sorbent at a very low milligram level was received by inserting a solution of the sorbent and disperser solvent into the aqueous sample. The cloudy solution created from the dispersion of the sorbent in the bulk aqueous sample. After pre-concentration of the diazinon, the cloudy solution was centrifuged and diazinon in the sediment phase dissolved in ethanol and determined by gas chromatography-flame ionization detector. Under the optimized conditions (pH of solution = 7.0, Sorbent: benzophenone, 2%, Disperser solvent: ethanol, 500 μL, Centrifuge: centrifuged at 4000 rpm for 3 min), the method detection limit for diazinon was 0.2, 0.3, 0.3 and 0.3 μg L−1 for distilled water, lake water, waste water and urine sample, respectively. Furthermore, the pre-concentration factor was 363.8, 356.1, 360.7 and 353.38 in distilled water, waste water, lake water and urine sample, respectively. SA-DSPE was successfully used for trace monitoring of diazinon in urine, lake and waste water samples.