Pervaporation as interface between solid samples and capillary electrophoresis

A fully automated system for solid sample analysis has been developed by on-line coupling a pervaporation module with a capillary electrophoresis system using as interface a flow injection manifold and a modified capillary electrophoresis vial. The pervaporator allows leaching, formation of the volatile analytes and their removal by evaporation and diffusion through a membrane. The isolated analytes are on-line injected into the capillary electrophoresis system meanwhile the solid matrix remains in the pervaporator. By this approach biogenic amines have been determined in fish, meat and sausage. The detection limits (LOD) ranged between 0.2 and 0.6 μg/ml, the quantification limits between 0.7 and 1.9 μg/ml and the linear dynamic between 0.4 and 400 μg/ml. The precision, expressed as relative standard deviation (RSD), ranged between 0.76 and 4.21% for repeatability and between 1.12 and 4.78% for within laboratory reproducibility. The errors, expressed as RSD for all compounds, ranged between 1.64 and 3.42%. The optimal pervaporation time and that necessary for the individual separation/detection of the target analytes are 14 and 12 min, respectively. The analysis frequency is higher than 3 h−1 and the sample size 0.1 g. A two-tailed t-test, used to compare the proposed method with that based on HPLC, yielded similar results for nine different samples.