UV-detection capillary electrophoresis for benzo[a]pyrene and pyrene following a two-step concentration system using homogeneous liquid–liquid extraction and a sweeping method

Abstract

10⁻⁹ mol l⁻¹ levels of polycyclic aromatic hydrocarbons (PAHs) suspected for certain noxious materials can be determined and separated by UV-detection capillary electrophoresis following a two-step concentration system. When the conditions of the homogeneous liquid–liquid extraction were [THF]_T = 5 vol%, [HCl]_T = 0.66 mol l⁻¹, and [PFOA]_T = 2 × 10⁻³ mol l⁻¹ (i.e., the volume of sample solution; 50 ml → sedimented phase; 30 μl), the extraction percentages of benzo[a]pyrene (Bap) and pyrene (Py) at 10⁻⁶ mol l⁻¹ were 102 and 97.5%, respectively. Also, when the total concentration factor(volume ratio), which includes that of the sweeping method, was 8335-fold, the determination range of Bap was 6.4 × 10⁻⁹–8.0 × 10⁻⁷ mol l⁻¹ and for Py, 8.0 × 10⁻⁹–7.0 × 10⁻⁷ mol l⁻¹. The detection limits (3σ) of Bap and Py were 1.6 × 10⁻⁹ and 4.8 × 10⁻⁹ mol l⁻¹, respectively.