1. Department of Chemistry; Faculty of Science, Universiti Putra Malaysia, 43400 Serdang; Selangor D.E. Malaysia
2. WestCHEM; Department of Pure and Applied Chemistry, University of Strathclyde, Thomas Graham Building; 295 Cathedral Street, Glasgow G1 1XL Scotland U.K.
3. Department of Chemical and Environmental Engineering; Faculty of Engineering, Universiti Putra Malaysia, 43400 Serdang; Selangor D.E. Malaysia
4. School of Chemical Sciences and Food Technology; Faculty of Science and Food Technology, Universiti Kebangsaan Malaysia, 43600 Bangi; Selangor D.E. Malaysia