The analysis of hair provides forensic toxicologists with several significant benefits in casework. Not only is it utilized when more conventional matrices such as blood and urine are not available, but also it provides an approximate timeline of drug use. Hair analysis is particularly useful in cases of child custody, workplace drug testing or in drug facilitated sexual assault cases. In a new paper authored by Lorna A Nesbit et al., published in Journal of Analytical Toxicology (doi: 10.1093/jat/bkx053) a group of NPS compounds (25B-, 25C- and 4-iodo-2,5-dimethoxy-N-[(2-methoxyphenyl)methyl]-benzeneethanamine) and 25I-NBOMe, using 4-bromo-2,5-dimethoxy-N-[(2-methoxyphenyl)methyl]-benzeneethanamine (25B-NBOMe)-D3, were analyzed using UCT’s flagship SPE sorbent Clean Screen® DAU (CSDAU133).  

The above noted NBOMes are a group of new psychoactive substances derived from phenethylamines. A validated method using Clean Screen® DAU and LC-MS/MS was developed according to SWGTOX parameters for their analysis in animal hair. In the study, Long-Evans rats (n = 55) were administered 25B-, 25C- or 25I-NBOMe at doses ranging from 30 to 300 μg/kg over a period of 10 days. Rats were shaved prior to their first dose and re-shaved after the 10-day period. Hair was separated by color (black: n = 55 and white: n = 55) and analyzed.

In the validated method, calibration curves with r2 values >0.99 were observed for matrix matched samples over concentrations ranging from 0.1 to 100 ng/mL and 0.025 to 2.5 ng/mg, respectively. The limits of detection (LOD) and quantification (LOQ) in hair ranged from 3 to 5 pg/mg and 6.25 to 12.5 pg/mg, respectively. Intra- and inter-day precision was <20% and accuracy was within ±20% for the matrix. The method was shown to be selective for both exogenous and endogenous compounds. No matrix effects were observed for the hair matrix. Solid phase extraction recovery ranged from 80 to 107% for hair samples.

This animal study demonstrates the efficiency of the Clean Screen®DAU sorbent in NPS analysis when applied to hair testing and why analysts turn to UCT as their first choice in SPE materials. For more information about Clean Screen®sorbents, go to https://sampleprep.unitedchem.com/products/spe/clinical-forensic/clean-screen-dau.