ORIGINAL PAPER Platinum in PM 2.5 of the metropolitan area of Mexico City Ofelia Morton-Bermea • Omar Amador-Mun ˜oz • Lida Martı ´nez-Trejo • Elizabeth Herna ´ndez-A ´ lvarez • Laura Beramendi-Orosco • Marı ´a Elena Garcı ´a-Arreola Received: 2 September 2013 / Accepted: 12 February 2014 Ó Springer Science+Business Media Dordrecht 2014 Abstract The increase in platinum (Pt) in the airborne particulate matter with size B2.5 lm (PM 2.5 ) in urban environments may be interpreted as result of the abrasion and deterioration of automobile catalyst. Nowadays, about four million vehicles in Mexico City use catalytic converters, which means that their impact should be considered. In order to evaluate the contribution of Pt to environmental pollution of the metropolitan area of Mexico City (MAMC), airborne PM 2.5 was collected at five differ- ent sites in the urban area (NW, NE, C, SW, SE) in 2011 during April (dry-warm season), August (rainy season) and December (dry-cold season). Analytical determinations were carried out using a ICP-MS with a collision cell and kinetic energy discrimination. The analytical and instrument performance was evaluated with standard road dust reference material (BCR-723). Median Pt concentration in the analyzed particulate was is 38.4 pg m -3 (minimal value 1 pg m -3 maxi- mal value 79 pg m -3 ). Obtained Pt concentrations are higher than those reported for other urban areas. Spatial variation shows that SW had Pt concentration significantly higher than NW and C only. Seasonal variation shows that Pt median was higher in rainy season than in both dry seasons. A comparison of these results with previously reported data of PM 10 from 1991 and 2003 in the same studied area shows a worrying increase in the concentration of Pt in the air environment of MAMC. O. Morton-Bermea (&) Á E. Herna ´ndez-A ´ lvarez Instituto de Geofı ´sica, Universidad Nacional Auto ´noma de Me ´xico, Ciudad Universitaria, 04150 Mexico, DF, Mexico e-mail: omorton@geofisica.unam.mx E. Herna ´ndez-A ´ lvarez e-mail: aeliza@geofisica.unam.mx O. Amador-Mun ˜oz Centro de Ciencias de la Atmo ´sfera, Universidad Nacional Auto ´noma de Me ´xico, 04150 Mexico, DF, Mexico e-mail: oam@atmosfera.unam.mx L. Martı ´nez-Trejo Facultad de Quı ´mica, Universidad Nacional Auto ´noma de Me ´xico, 04150 Mexico, DF, Mexico e-mail: atalita@gmail.com L. Beramendi-Orosco Instituto de Geologı ´a, Universidad Nacional Auto ´noma de Me ´xico, 04150 Mexico, DF, Mexico e-mail: laurab@geologia.unam.mx M. E. Garcı ´a-Arreola Instituto de Geologı ´a, Universidad Auto ´noma de San Luis Potosı ´, 78240 San Luis Potosı ´, SLP Mexico, DF, Mexico e-mail: maria.garcia@uaslp.mx 123 Environ Geochem Health DOI 10.1007/s10653-014-9613-8