Why the first blotter measurements were called estimates
An analytical study published online in 2016 examined AL-LAD blotters and estimated the amount recovered from the paper. The researchers also checked recovery using blank blotters, accounting for material that might not be recovered during extraction.
They still described the results as semi-quantitative. Certified reference material was unavailable, and the purity of the AL-LAD powder used for calibration was uncertain. The distinction is useful: correcting extraction losses improves a measurement, but it does not resolve uncertainty in the reference used to calculate it.








Reviews
There are no reviews yet.