Determination of Polycyclic Aromatic Hydrocarbons in the Presence of Humic Acid in water
The presence of humic acid (HA) makes it extremely difficult to determine and quantify accurately polycyclic aromatic hydrocarbons (PAHs) in aquatic environment because of their complex and strong interaction. To solve this problem, a new method was developed in this work through the combination of PARAFAC and fluorescence spectroscopy, which mainly includes: (1) the fluorescence quantum yield acquisition of PAHs with and without HA by PARAFAC; (2) the concentration score correction of PAHs in validation and test sets using the fluorescence quantum yields; and (3) the prediction of PAHs concentration in the validation and test sets in the presence of HA by corrected concentration. Using this method, the PAHs concentration on the level of µg L−1 in the test samples with HA of 2.5 mg/L and 5.0 mg/L can be successfully predicted with the root mean square error below 0.15 µg L−1, relative error of prediction below 4% for validation samples, recoveries of each PAH between 82.5% and 102.6% for test samples.
Exploration of minimum energy conical intersection structures of small polycyclic aromatic hydrocarbons: toward an understanding of the size dependence of fluorescence quantum yields
