Discussion Category: Ion Chromatography
Detection of PO4 by IC
When running IC-2000, normally I got the peak of Chloride, Sulfate and Phosphate but after analysising the sample with high concentration of SO4 (maybe 400 ppm) and then the peak of PO4 did not appear, even with high concentration 20 ppm. The peak of Cl and SO4 are still present. I tried to run with a lot of sample with MQ water, but still can not get the peak of PO4?. What is the problem with IC. Thank you.
Reply byIt's possible that the retention time has shifted due to the matrix or the high concentration of SO4. Also, the SO4 peak might be so broad that it "runs over" into the PO4.
I suggest you spike the sample with PO4 to see where the peak appears. Run the sample without the spike and you should see the PO4 at the same retention time.
Reply byI run the IC with the sample spiked with only PO4 and no peak apear. With the sample of Chloride only or sulfate only, the peak of Chloride or Sulfate appeared.
Reply byDo you make your own standards? Try running a higher concentration standard to see if you can get it to even show up. Then you know if you are having an issue with PO4 being suppressed in its response or totally not showing up.