Automated fast procedure for the simultaneous extraction of hair sample performed with an automated workstation.
BACKGROUND
Hair testing has a leading role in toxicology practice and even more in those aspects tightly linked to the assessment of psychoactive drug use and abuse in social life.


OBJECTIVE
The objective of the present study was to develop and validate an automated SPE sample-preparation step, suited for GC/MS confirmation analysis of basic drugs in hair drug control. The method was studied and optimized for quantitative determination and in a second time it was extended to real hair samples. The purpose of method validation was to ensure good reliability, reproducibility and quickness.


METHODS
Janus Automated Workstation (PerkinElmer) was employed to perform SPE hair extraction, using 96-well plate SPEC MP1 acquired from Varian (Agilent Technologies). After derivatization of dried extracts, screening confirmations were performed using gas chromatography (GC) followed by mass spectrometry (MS). GC/MS data were validated following standard guidelines, but our attention was focused on three headings: samples cross-contamination, "memory effect" and extraction recovery.


RESULTS
Validation requests were fully accomplished and we always obtained best results with the automated procedure. For instance, analytes mean recovery was between 70 and 90% and data analysis proved that no contamination between samples occurred.


CONCLUSIONS
The automated workstation has shown good reliability (cross contamination and "memory effect" were tested and excluded), effectiveness (no false negative was detected), solvent saving (500μL/sample vs traditionally LLE 4mL/sample) and quickness (50min for 96 tests cycle).
Section of Forensic Toxicology, Department of Human Physiology, University of Milan, Italy. ilaria.angeli@unimi.it
I
I
Angeli
M
M
Minoli
A
A
Ravelli
F
F
Gigli
F
F
Lodi
D057205:Automation, Laboratory; D053593:Forensic Toxicology / Q000379:methods; D008401:Gas Chromatography-Mass Spectrometry; D006197:Hair / Q000737:chemistry*; D006801:Humans; D009294:Narcotics / Q000032:analysis*; D015203:Reproducibility of Results; D052616:Solid Phase Extraction; D015813:Substance Abuse Detection / Q000379:methods
D009294:Narcotics