We are interested information of collegues with Personal experience in stability of pyruvate in serum/plasma and aquous standards. Literature citations are sometimes contradictory. Thanks for the trouble taken.

I have limited experience with the stability of pyruvate standards in aqueous solution but none with regard to stability in serum/plasma. I would classify pyruvate as a relatively unstable material in aqueous solution. For all organic acid standards, you must assume that bacterial contamination will result in decline of peak area, especially at low concentrations. Usually, I work from one gram per liter stock solutions which I store in the refrigerator and then I prepare standards daily from these stock solutions. The stock solutions are usually stable for weeks to months provided your deionized water system is not contaminated with bacteria. In the case of pyruvate, the stock solution is significantly less stable. Generally, to be on the safe side it is desirable to make up the standard more often given the chemical instability of pyruvate. If I am using the standard for quantitative work, I would prepared the stock solution daily.

One of the members of this group mailed me that aquous standards as well as samples are stable for at least 8 weeks at -80 C.

Best regards

R.W.Wulkan