1. Inorganic and Physical Chemistry Division Faculty of Mathematics and Natural Sciences Institut Teknologi Bandung Jalan Ganesha No. 10 Bandung Jawa Barat 40132 Indonesia
2. Education Office of North Sumatera Province Jalan Cik di Tiro No. 1‐d Medan Sumatera Utara 20151 Indonesia
3. Electromedic Technology Program STIKes Binalita Sudama Medan Jalan Gedung PBSI Pasar V Medan Sumatera Utara 20371 Indonesia
4. Analytical Chemistry Division Faculty of Mathematics and Natural Sciences Universitas Lampung Jalan Prof. Dr. Sumantri Brojonegoro No. 1 Bandar Lampung Lampung 35145 Indonesia
5. Chemistry Department Faculty of Mathematics and Natural Sciences Universitas Sebelas Maret Jalan Ir. Sutami No. 36A Kentingan Surakarta, Jawa Tengah 57126 Indonesia
6. Organic Chemistry Division, Chemistry Program Faculty of Mathematics and Natural Sciences Institut Teknologi Bandung Jalan Ganesha No. 10 Bandung, Jawa Barat 40132 Indonesia