A new configuration for in-tube solid phase microextraction based on a thin-film coating

Abstract

In the present research, in-tube solid phase microextraction and thin-film microextraction were combined in a new configuration in order to use the advantages of both techniques. For this purpose, poly(ortho-phenylenediamine) thin-film was electrodeposited on stainless-steel sheets. The sheets were inserted into a cartridge. The resulting configuration was used for in-tube solid phase microextraction of chlorophenols as model analytes. The analytes were separated and detected by high performance liquid chromatography coupled with ultraviolet detection. The important factors affecting the extraction such as the pH (6) and salt concentration of the sample solution (0%), extraction time (15 min), extraction and desorption flow rates (6 mL min−1 and 70 µL min−1, respectively), and desorption solvent type and volume (methanol, 500 µL) were optimized. The presented method can detect model analytes at concentrations as low as 0.3 µg L−1. The method showed good linearity in the range of 0.8–100.0 µg L−1 of chlorophenols with coefficients of determination better than 0.9945. The intraday and interday precisions were in the range of 1.3–5.8% and 3.5–8.3%, respectively. The tube-to-tube repeatability of the method was lower than 13.0%. Finally, the validated method was successfully used for the analysis of the selected analytes in real samples including rain water and honey.