Abstract
The sensitivity and specificity of a novel method of screening for cocaine in hair, based on matrix-assisted laser desorption/ionisation (MALDI) mass spectrometry (MS), have been evaluated. The method entails a rapid extraction procedure consisting of shaking 2.5 mg pulverised hair at high frequency in the presence of an acidic solution (160 µL of water, 20 µL of acetonitrile and 20 µL of 1 M trifluoroacetic acid) and a stainless-steel bullet. Following centrifugation, the supernatant is dried under a nitrogen stream, and the residue is reconstituted in 10 µL of methanol/trifluoroacetic acid (7:3; v/v). One microlitre of the extract is deposed on a MALDI sample holder previously scrubbed with graphite; an α-cyano-4-hydroxycinnamic acid (matrix) solution is electrosprayed over the dried sample surface to achieve a uniform distribution of matrix crystals. The identification of cocaine is obtained by post-source decay experiments performed on its MH+ ion (m/z 304), with a limit of detection of 0.1 ng/mg of cocaine. A total of 304 hair samples were analysed in parallel by MALDI-MS and a reference gas chromatography-MS method. The obtained results demonstrate specificity and sensitivity of 100% for MALDI-MS. Evidence of cocaine presence was easily obtained even when hair samples exhibiting particularly low cocaine levels (<0.5 ng/mg) were analysed.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Musshoff F, Madea B (2007) Anal Bioanal Chem 388:1475–1494
Kintz P, Villain M, Cirimele V (2006) Ther Drug Monit 28:442–446
Pragst F, Balikova MA (2006) Clin Chim Acta 370:17–49
Vogliardi S, Favretto D, Frison G, Ferrara SD, Seraglia R, Traldi P (2009) J Mass Spectrom 44:18–24
Society of Hair Testing (2004) Forensic Sci Int 145:83–84
Favretto D, Stocchero G, Vogliardi S, Frison G, Trevisanuto D, Castagna F, Ferrara SD (2009) Neonatal hair analysis by liquid chromatography-high-resolution mass spectrometry to reveal gestational exposure to venlafaxine. Ther Drug Monit. doi:10.1097/FTD.0b013e3181c01e16
Langley GJ, Herniman JM, Townell MS (2007) Rapid Commun Mass Spectrom 21:180–190
Molin L, Cristoni S, Crotti S, Bernardi LR, Seraglia R, Traldi P (2008) J Mass Spectrom 43:1512–1520
Grant ER, Cooks RG (1990) Science 250:61–68
Kaufmann R, Spengler B, Lutzenkirchen F (1993) Rapid Commun Mass Spectrom 7:902–910
Wang PP, Bartlett MG (1998) J Mass Spectrom 33:961–967
Kintz P, Mangin P (1995) Forensic Sci Int 73:93–100
Karni M, Mandelbaum A (1979) Organic Mass Spectrom 15:53–64
Moneti G, Francese S, Mastrobuoni G, Pieraccini G, Seraglia R, Valitutti G, Traldi P (2007) J Mass Spectrom 42:117–126
Feldsine P, Abeyta C, Andrews WH (2002) J AOAC Int 85:1187–1200
EURACHEM (1998) A laboratory guide to method validation and related topics, Teddington, Middlesex, UK. http://www.eurachem.ul.pt. Accessed 21 Sept 2009
Ellison SLR, Fearn T (2005) Trends Anal Chem 24:468–476
Trullols E, Ruisánchez I, Rius FX (2004) Trends Anal Chem 23:137–145
Author information
Authors and Affiliations
Corresponding author
Electronic supplementary material
Below is the link to the electronic supplementary material.
Figure S1
Matrix-assisted laser desorption/ionisation spectra obtained for positive samples containing cocaine at 0.5 ng/mg (a), 0.4 ng/mg (b), 0.5 ng/mg (c), 0.4 ng/mg (d) and 0.3 ng/mg (e) (JPEG 107 kb)
Figure S2
Product ion spectra obtained by post-source decay experiments on the ion at m/z 304 for the same samples of Figure S1 (JPEG 66 kb)
Figure S3
Distribution of cocaine concentration in 53 head and pubic hair samples (JPEG 35 kb)
Rights and permissions
About this article
Cite this article
Vogliardi, S., Favretto, D., Frison, G. et al. Validation of a fast screening method for the detection of cocaine in hair by MALDI-MS. Anal Bioanal Chem 396, 2435–2440 (2010). https://doi.org/10.1007/s00216-009-3387-3
Received:
Revised:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00216-009-3387-3