Hello, I am analyzing crude mixtures of biobased acrylic acid and another fermentation based organic hydroxyacid, and some related conversion products. i am using a Bio-Rad HPX-87H with 0.1% sulfuric acid, 50C, 0.6 mls/min, pretty standard for this column. I am currently looking for an exact replacement for this system from another manufacturer due to lousy customer service with Bio-Rad. I have found a couple that look very similar- Hamilton HC-75H+ and Agilent Hi-PlexH. Can anyone confirm these are close enough to give the same general results? the packings sound very similar, but each manf. claims proprietary advantages. I am also looking for a compatible guard column for my Bio-Rad column until it needs replacing. I am a small, recent start up lab, and Bio-Rad appears to be concerned I am only interested in reselling the products I buy- ridiculous. thanks for any ideas.