ion chromatography question

[arnhola1]

Hi,

Thanks for having this forum available. Can you explain how temperature variations affect ion chromtography whether it be increasing the temperature of the column, eluent, stationary phase? How does it affect peak separation or retention time?

Also, Can you explain the "matrix" in IC? How does the makeup affect the analysis by the IC?

Thanks.
AA

[tom jupille]

*Very* generally speaking, increasing the temperature decreases retention time (think about it this way, you are "dissolving" your analyte from the stationary phase to the mobile phase solvent; solubility tends to increase with temperaturew). The changes in retention may or may not be proportional for all analytes (compounds you are analyzing). If all the compounds behave the same way, then selectivity will not change. If they behave differently, then selectivity will change. For analyte ions of the same charge, selectivity changes are *usually* fairly small.

Generally the term "matrix" refers to the stuff you are analyzing (drinking water, orange juice, urine, soil . . .). Different matrices will require different sample preparation procedures, which can affect the results (just as a trivial example: would you use exactly the same procedure to analyze for chloride in drinking water or in soil?).

[arnhola1]

Thanks for that. It helps me alot!