Determination of BTEX in ambient air of Distrito Metropolitano de Quito by gas chromatography with flame ionization detector

Abstract

The environmental contamination can be natural or anthropogenic, so this can cause the presence of certain substances that may affect health and comfort of habitants. Because of this, Benzene, Toluene, Ethylbenzene, m/p -Xylene and o- Xylene was analyzed in the air of Distrito Metropolitano de Quito (DMQ). In Quito these compounds are present in car fuel, so the pollution sources and period of contamination can be identified and controlled, causing a reduction in the environmental impact. The determination of these compounds was done by passive sampling and then ultrasonic extraction using hexane as solvent for the further analysis in gas chromatography with flame ionization detector. The separation, identification and quantification of the compounds were possible because of the chromatography conditions that were used. BTEX was monitored in 43 places along DMQ, with a period of exposition of 30 days. The mean annual concentration obtained for benzene during October 2016 to January 2017 was 0,07 – 13,85 μ g/m 3 , value that exceed the environmental regulation established by the European Commission, 5 μ g/m 3 . The concentration of BTEX have been in- creasing in 2017 compared to previous years because of vehicular congestions as well as the use of fuel in festivities of December 2016 and January 2017.