Hello,
I have a Dionex DX500 system configured for anion analysis. I've recently been approached about quantifying Cl levels in a silica based slurry. The slurry has a pH of 2 and has about 2% solids in solution. I would welcome any suggestions and/or comments of how to tackle this analysis as well as how this would effect my system. Thank you in advance for your help.

In the first place there shouldn't be a problem with your sample matrix provided that you centrifuge or filter the sample to remove the insoluble silica prior to analysis. The amount of soluble silicate at pH 2 is too low to represent an issue under standard analysis conditions. Probably the safest thing to do would filter the sample with an 0.22 micron membrane filter but make sure the filter does not contribute any chloride blank. There could potentially be some analytical challenges with your sample matrix, however, depending upon the source of your low pH. Can you supply more details about other anions present in your matrix?

Chris,
Thanks for the info. I will have to find what the source of the low pH is. Unfortunately, all the slurry vendor will disclose is that it is an organic acid. The information is considered proprietary.

It is always fun to identify the "proprietary" component and then tell the supplier about it. sometimes one can get all sorts of useful additional information.

Since the low pH is derived from an organic acid, it might be advisable to use a relatively high-capacity hydroxide selective column such as the AS11-HC or the AS16. Be advised that you may need to dilute the filtrate prior to injection.