Sample matrix effect on the seperation of 2,3,7,8-tetrachlorodibenzo-p-dioxin and 2,3,7,8-tetrachlorodibenzo-p-furan using micellar electrokinetic chromatography

Abstract

The effect of sample matrix on the separation of two selected dioxin-related compounds i.e. 2,3,7,8-tetrachloro-dibenzo-p-dioxin (2378-TCDF) and 2,3,7,8-tetrachlorodibenzo-p-furan (2378-TCDF) using micellar electro-kinetic chromatography (MEKC) was investigated. The samples were prepared in aqueous and non-aqueous media at equal concentrations. The non-aqueous media used is ethanol while the aqueous media are water and buffer matrix. The best separation efficiency for these two dioxin-related compounds was obtained with the analytes dissolved in the sample buffer matrix (280,000 plates for 2378-TCDF and 180,000 plates for 2378-TCDD) but the analytes dissolved in water matrix produced the highest peak area and peak height. Sensitivity enhancement for both analytes in water increased 3 fold for 2378-TCDF and 5 fold for 2378-TCDD, respectively compared to analytes dissolved in buffer matrix. The separation efficiency for these two analytes in water matrix were 200,000 plates for 2378-TCDF and 100,000 plates for 2378-TCDD and a more stable baseline was obtained as compared to non-aqueous media.