DETERMINATION OF POLYCYCLIC AROMATIC HYDROCARBONS (PAHs) IN SUPERFICIAL WATER AND SEDIMENT OF LAKE TECOCOMULCO, MEXICO

To evaluate the environmental quality of bodies of water it is essential to know the risk that using it represents to human health, as well as to the floral and fauna present. This information is derived from knowledge of the concentrations of any toxic substances present in the water body under study. The objective of the present work was to evaluate the presence and concentrations of 16 US EPA priority polycyclic aromatic hydrocarbons (PAHs) in abiotic environmental matrices of Tecocomulco Lake, Hidalgo, Mexico. Samples from six localities were selected according to accessibility. From each locality, three samples of water and of sediment were taken from three different points, and samples from each point were combined to make three compound samples from each locality. Extraction of PAHs from water was carried out by solid phase extraction with C18; extraction from sediments following the EPA 3550C method. Analyses were made using a gas chromatograph connected to a mass spectrophotometer (CG-MS). The highest concentration of PAH in water was for acenaphthylene (2.400mgl-1), anthracene (1.770mgl-1), and phenanthrene (1,500mgl-1); in sediment the highest concentrations corresponded to naphthalene (2.155mgl-1), benzo[g,h,i]perylene (4.940mgl-1), and fluoranthene (2.240mgl-1). The ?PAHs showed a noticeable difference between matrices, a concentration of 6.658mgl-1 in water and 10.927mgkg-1 in sediment, with a total ?PAHs of 17.585mgkg-1. Details of the methodology are included to facilitate similar studies.