title: Nails are a potential alternative matrix to hair for drug analysis in general unknown screenings by liquid-chromatography quadrupole time-of-flight mass spectrometry.
abstract: OBJECTIVE
  In this study, the usefulness of nail samples instead of hair for a general unknown screening (GUS) for drugs was tested. An alternative matrix for long term detection is still needed in cases where no hair is available for analysis.
  
  
  METHODS
  Hair and nail samples from 70 postmortem cases were analyzed by liquid-chromatography quadrupole time-of-flight mass spectrometry. Hair and nail samples were ground by a ball mill and extracted twice for 18 h. Extracts were measured in Auto MS/MS mode (data dependent mode acquisition).
  
  
  RESULTS
  Only 10% of the cases showed a disagreement of results in hair and nail analysis where hair samples were tested positive and corresponding nail samples were tested negative in a general unknown screening for drugs. In most of the cases investigated the analysis of the nail clippings and whole nail samples led to results comparable to those obtained from hair analysis. The incorporation of a large number of substances into the nail matrix was proven by the detection of 89 different analytes (e.g. antidepressants, drugs of abuse or antihypertonics) in our tests.
  
  
  CONCLUSIONS
  In cases where the amount of hair available is not sufficient for a general unknown screening for drugs, nails appear to be a useful comparable matrix for the detection of long-term drug consumption due to the comparison of the qualitative GUS results from the hair and nail samples in this study.
authors.affiliation: Institute of Legal Medicine and Forensic Sciences, Charité-University Medicine Berlin, Turmstrasse 21, Haus N, 10559, Berlin, Germany, franziska.krumbiegel@charite.de.
authors.forename: Franziska
authors.initials: F
authors.lastname: Krumbiegel
authors.forename: Martin
authors.initials: M
authors.lastname: Hastedt
authors.forename: Michael
authors.initials: M
authors.lastname: Tsokos
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001344:Autopsy; D002853:Chromatography, Liquid; D005260:Female; D006197:Hair / Q000737:chemistry*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009262:Nails / Q000737:chemistry*; D011180:Postmortem Changes; D015203:Reproducibility of Results; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D015813:Substance Abuse Detection / Q000379:methods*; D019966:Substance-Related Disorders / Q000175:diagnosis* / Q000378:metabolism; D053719:Tandem Mass Spectrometry; D055815:Young Adult