With our own R&D and Tech& Trade service, we, Shanghai Tonk Bio-tech Co. Ltd, have been specializing in the manufacture and the development of Imidazole, Ammonium salts and their new products and new intermediates. Our production base is in Zhejiang provience, it has well equipped with Lab, test facilities and advanced production line. We've established a good quality control system as well and obtained the Certificate of ISO9001-2000 Quality Guarantee System.