Thanks for the link. I can't access the full article (without paying for it), but I see in the Abstract they claim a relatively low variability in levels over time in the same subject. This is not what another study that I posted here last summer claimed, and which I took at the time to be a major break for Bert. If the variability is as low as they claim, and if Bert's levels of DEHP are what that original graph that was posted here way back when shows, then this is bad news for him. All the published studies I have seen indicate that transfusers generally have very high levels of DEHP; the question is one of false positives, i.e., what proportion of non-transfusers may have similarly high levels, at least some of the time. If there are significant proportion of false positives, then this method isn't going to be acceptable. This study seems to be claiming that false positives can be reduced to a very low level.
But of course, this is not a validated test, and can be used only as supporting evidence for a case. So the question is how much value will be given to Bert's DEHP levels, again, assuming that they really were as reported originally.