Métodos para análises de hpa e btex em águas subterrâneas de postos de revenda de combustíveis: Um estudo de caso em Campo Grande, MS, Brasil

Abstract

Two methods using headspace solid-phase microextraction and gas chromatography-mass spectrometry were developed for the determination of polycyclic aromatic hydrocarbons (PAH) and BTEX. Best results were obtained using DVB/CAR/PDMS fiber, with 10 min extraction at 25 °C and 0.15 min desorption at 260 °C (BTEX), and PDMS/DVB fiber, with 60 min extraction at 90 °C, 10% NaCl and 5 min desorption at 270 °C (PAH). LOD intervals were 3×10-2 - 5×10-2 μg L-1 (BTEX) and 1.6×10-3 - 1.4 μg L-1 (PAH). The methods were applied to forty-five groundwater samples from monitoring wells of gas stations and only benzene level exceeded the limit established by Brazilian regulations.