Regarding quantification of Succinylacetone

[chandra]

Hello friends,

There is a question that gives me the nightmare from quite some times. I have quantified succinylacetone in normal urine sample and found its concentration much higher than the normal range that is described in literature.Can anybody tell me what is the possible reason for this.Is my analyte is coeluting with some other compound having same ions that have taken as qualifier ion.Please answer.

Chandra

[rb6banjo]

I'm not familiar with the accepted methodology. Is it GC or LC? Have you explored all of the possibilities for flushing out a coeluter (changing the temperature program, gradient conditions, columns, etc.)? Also, when you are looking at the marker ions, you are ratioing them, right? Generally, the conditions for positive ID of a component are: 1) the right masses have to occur in the mass spectrum AND 2) they must be in the correct ratio.

[Don_Hilton]

And if doing LC, ion supression in the location of an internal standard but not the analyte will give high falsely high results. A bit more detail on the method and chromatograms will give better focused guesses and information. (And I won't mention having run into a similar problem, only to discover that a decimal point wandered in the calculation of standards...)