Due to the production process of methylglyoxal used for many commercial preparations, such products contain formaldehyde in ill defined quantities. According to the literature (i.e. Pourmotabbed T, Creighton DJ.J Biol Chem. 1986 Oct 25;261(30):14240-4), this contamination can easily be 10 % (mol/mol) or more.

We have now estimated the amount of formaldehyde in our current methylglyoxal lot (Sigma) by using a method described by Deng and Yu (Journal of Chromatographic Science, Vol. 37, September 1999). Although the chromatogrammes did not look perfect, we were able to get an estimate of about 8% formaldehyde contamination (mol/mol), This is very similar to the amounts that have been published 1986. However, according to our experiments this formaldehyde contamination did not contribute to signalling events triggered by methylglyoxal in cell cultures, but I think, the toxicity of this methylglyoxal lot might be in part due to formaldehyde, which is approximately 10-times as toxic as the methylglyoxal lot itself. What is the opinion of other researchers doing experiments with methylglyoxal?