Dionex Corporation is an American company based in Sunnyvale, California. Dionex products have been empowering scientists in the environmental, life science, chemical/petrochemical, food safety, electronics, power, and biofuel industries.

In December 2010 Thermo Fisher Scientific announced its acquisition of Dionex.

Thermo Scientific Dionex ion chromatography systems are the trusted brand in chromatography and the technology leader for over 40 years. 

Thermo Scientific Dionex products have a reputation for leading innovation with excellence in ion chromatography (IC), liquid chromatography (HPLC and UHPLC), automated sample preparation solutions, and chromatography data system software.