Zhengzhou Sigma Chemical Co., LTD. is located in the central area of China--Zhengzhou City, Henan Province. It is a complex enterprise which integrates scientific research, production and trade. Zhengzhou Chemical Chem Co., Ltd., a Hi-tech enterprise, subordinates to it. It has the advanced R&D center, modernizational inspection center, standardized GMP workshop, large scale production base and informationalized trade group. The main products of Zhengzhou Sigma Chemical Co., LTD. are: adv...