Programed nebulizing-gas pressure mode for quantitative capillary electrophoresis-mass spectrometry analysis of endocrine disruptors in honey

The application of programed nebulizing-gas pressure (PNP) has been previously described to be a simple strategy for the separation of anions by capillary electrophoresis-electrospray-mass spectrometry (CE-ESI-MS). The PNP mode provided high resolution and stable analyses and also had the advantage of allowing the use of capillaries wider than the 5075 mu m conventional ones. Here, the application of the PNP approach to the quantitative analysis of pollutants in real samples by CE-ESI-MS is described for the first time; in particular, for the determination several endocrine disruptors (2,4-dichlorophenol, 2,4,5-trichlorophenol, pentachlorophenol, bisphenol-A, 4-tert-butyl-phenol, and 4-tert-butyl benzoic acid) in honey. For sample pretreatment, different liquidliquid extraction (LLE) procedures were assayed and compared to the QuEChERS (c) methodology prior to electrophoretic analysis. With the application of the PNP approach to CE-ESI-MS, the limits of detection achieved were in the 14 ng/g range with a simple liquidliquid procedure without any further clean-up step; relative standard deviation values in the 29% range were found. The analytical characteristics allow the proposed method to be used in the control analysis of these compounds in honey.