Chromatography Forum

Looking for suggestions on silica/silicate analysis without the use of ICP or post-column derivitization for supressed conductivity. Any thoughts?

Direct (unsuppressed) conductivity should work with a high-pH buffer. The conductivity signal will decrease when silicate elutes.

I've had some luck in the past with an Ion Exclusion column using just water as the mobile phase and conductivity as the detector. Due to the low background the method is also quite sensitive. The Dionex ICE AS1 column worked well for me. We were using this for high purity water applications, i.e. there were very few other anions in the matrix. If you have alot of other things in the aqueous matrix then this would not be a good choice.