Not a chemist, but it doesn't look simple to test for:

https://en.wikipedia.org/wiki/Bongkrek_acid

And with poisoning cases so rare, there's not much motive to develop & use a test.

Might anyone be more familiar with this area?

The dangers of bongkrekic acid

Tricky one this, the article is in German, and behind a paywall.

I went to:

https://archive.ph/x0Xg5

And was able to use my iPhone translate to English function, first time.