1. PQ Corporation, Research and Development Center, 280 Cedar Grove Road, Conshohocken, Pennsylvania 19428, United States
2. Faculty of Chemistry, Department Adsorption, M. Curie-Sklodowska University, M. Curie-Sklodowska Sq.3, 20031 Lublin, Poland
3. Analytical & System Research, Arkema Inc., 900 First Avenue, King of Prussia, Pennsylvania 19406-0936, United States