WEF Discussion Forums
Laboratory Management and Technical Issues
I need an LCS for TDS/VDS. I am using NaCl, but need another compound to combine with it that will hold at 180 degrees but then volatilize at 550 degrees. Any suggestions?
Potassium hydrogen phthalate (KHP) should work, Jami. Being very soluble in water, a 300 mg/L solution of KHP should give a TDS of 300 mg/L. A study by the joint EPA Region 1/WA State Dept of Ecology lab found the same 300 mg/L solution gave an average total volatile solids of 169 mg/L.
If you decide to try KHP, be aware that it is hygroscopic...dry it at 105°C, store it in a desiccator, and weigh it immediately after removing from the desiccator.
Thanks Perry! I'm giving it a try today. Looking forward to the results... your help is very much appreciated.