Do a 'Google' search and also asked Dionex. You can also review the websites for Waters, Agilent, Phenomenex, and Restek... The real answer depends on your sample matrix and the cocentration level you require (ppm, ppb or ppt)
You can use indirect ion chromatography to analyze for CO3. pH is, of course, far and away the best way to measure OH. If you are in clean waters you can titrate for the CO3 but that is subject to many interferences. Indirect IC can be run on a conventional HPLC-UV system so it is not expensive to set up.