Electro-enhanced solid-phase microextraction for metronidazole determination in aqueous samples

A stainless steel wire was platinized using electrophoretic deposition (EPD) method to create a high-area and cohesive surface. The platinized fiber was coated by PANI/MWCNT nanocomposite by electrochemical polymerization and applied in electro-enhanced solid phase microextraction (EE-SPME) strategy, as a simple, efficient and low-cost analytical method for extraction and determination of metronidazole (as a basic drug) from aqueous sample. The ionic analyte was extracted from an acidified aqueous solution (sample) on the sorbent (extractive phase) under a constant DC potential. The extraction efficiency of analyte was evaluated by its ion mobility spectrometry (IMS) determination. Different important experimental variables that affect the efficiency of the developed EE-SPME method including pH, ionic strength, extraction time, and applied DC potential were studied and optimized. The linear dynamic range (LDR) was found to be in the range of 0.1-500 ng mL-1 (R2> 0.997) and the limit of detection (LOD) was obtained 0.01 ng mL-1. The recovery of the proposed EE-SPME-IMS method was calculated 95%. The relative standard deviation (RSD) for 6 repeated analyses of 1 ng mL-1 of analyte was calculated to be 9%. Finally, the proposed EE-SPME-IMS procedure was successfully applied for the extraction and determination of metronidazole from aqueous media samples.

Keywords:

EE-SPME , PANI/MWCNT coated fiber , metronidazole , IMS