Selective and efficient sampling of nitrogen-containing compounds from air by in-tube extraction devices packed with zinc oxide-modified mesoporous silica microspheres oleh Eka Dian Pusfitasari, Cristina Youngren, Jose Ruiz-Jimenez, Saara Sirkiä, Jan-Henrik Smått, Kari Hartonen, Marja-Liisa Riekkola