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

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 x 10(-3) mol l(-1) (i.e., the volume of sample solution; 50 ml --> sedimented phase; 30 mul), 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 x 10(-9)-8.0 x 10(-7) mol l(-1) and for Py, 8.0 x 10(-9)-7.0 x 10(-7) mol l(-1). The detection limits (3 sigma) of Bap and Py were 1.6 x 10(-9) and 4.8 x 10(-9) mol l(-1), respectively.