Yup. They're extrapolating from uncalibrated GC/MS curves, and normalizing by mass of pre-processed sample. They also don't give any of the un-normalized data. I have zero faith in the accuracy of these numbers, but some faith in the inter-group comparisons.
The sensitivity of the GC/MS method makes me hypothesize that the stated values are massively inflated. Whatever error there was in that original measurement is probably amplified like crazy in scaling up to ug/g estimates.
The sensitivity of the GC/MS method makes me hypothesize that the stated values are massively inflated. Whatever error there was in that original measurement is probably amplified like crazy in scaling up to ug/g estimates.