Chemical characterization of fine fractions of particulate matter. Atmospheric pollutants analytical methods development and validation. Application of multivariate statistical methods (PCA, DFA, CA, APCS, TTFA, CMB, DFA etc… for the source apportionment. Black carbon, Organic carbon and Water Soluble Organic Carbon studies both in PM segregated samples and PM10, PM2,5 and PM1 samples, collected in urban and remote areas. Indoor air quality: physical-chemical characterization of fine fractions of particulate matter. NOx and VOCs photocatalytic degradation assisted by nanocrystalline TiO2.