Solid-phase microextraction as a clean-up and preconcentration procedure for organochlorine pesticides determination in fish tissue by gas chromatography with electron capture detection

The feasibility of developing a single-step clean-up, enrichment procedure for organochlorine pesticides (OCPs) in fish tissue samples based on solid-phase microextraction (SPME) was investigated. The general analytical methodology developed combines conventional solid-liquid extraction of the OCPs from the sample using an organic solvent with SPME over the organic extract followed by gas chromatography–electron-capture detection (GC–ECD) analysis. Experimental SPME conditions such as extraction time, temperature and matrix effects were optimised. Under optimised conditions, precision, linearity range, detection limits and accuracy were evaluated. Detection limits obtained for fish tissue samples were in the range of 0.1–0.7 ng g−1. Good recoveries (over 70% in all cases) were achieved from samples spiked at a concentration level of 10 ng g-1. The accuracy of the developed SPME–GC–ECD procedure in real samples has been verified by analysing, using the standard addition method, a certified reference material (CRM 430, OCPs in pork fat) with satisfactory results.