COMPUTER-ASSISTED METHOD FOR THE THRESHOLD OPTIMIZATION OF FLUORESCENCE DETECTION CONDITIONS IN HPLC OF POLYCYCLIC AROMATIC HYDROCARBONS

摘要

The computer assisted method of lambda(ex), lambda(em) optimization in programmed fluorescence detection of PAHs included in EPA norm has been investigated. Optimization procedure utilises the preference of the threshold methods. Finding of optimum detection conditions was done in the reduced parametric space (lambda(ex), lambda(em)). This space consisted of points with guaranteed minimal detection sensitivities of tested PAHs. The relative detection sensitivities of PAHs, elution characteristics, different natural fluorescences, chromatographic resolution of hardly separable pairs of peaks and also the reproducibilities of peak heights and retention times under gradient conditions were taken into consideration. The results of optimization indicate that it is difficlut to find acceptable compromise for fluoranthene and chrysene. By shifting of emmision wavelength the sensitivities of chrysene and fluoranthene changed in the mutually opposite direction. Therefore developed program used five steps. Fluoranthene, pyrene and benzo(a)anthracene, chrysene were measured at different detection conditions. If there is a specific need to analyse most dangerous PAHs then the program can be adjusted accordingly.