[Prediction of photolysis half-lives of PCDD /Fs adsorbed on spruce needles optimized by genetic algorithm]

Adopting quantum chemical parameters of PCDD/Fs computed with quantum chemical PM3 algorithm, quantitative structure-property relationship (QSPR) model, which could predict photolysis half-life (t1/2) of PCDD/Fs adsorbed to spruce [Picea abies (L.) Karst.] needle surfaces, is established using genetic algorithm (GA) algorithm. It is considered that the main factors affecting lg t1/2 of PCDD/Fs are the energy of the highest occupied molecular orbital (EHOMO), ELUMO - EHOMO and average molecular polarizability (alpha). The lg t1/2 values increase with the increasing of EHOMO and a. The relationship between the lg t1/2 values and ELUMO - EHOMO is a parabolic curve. The lg t1/2 values increase with the increasing of ELUMO - EHOMO when ELUMO - EHOMO > or = 7.847 and decrease with the increasing of when ELUMO - EHOMO < or = 7.847.