Detection of methamphetamine and its main metabolite in fingermarks by liquid chromatography–mass spectrometry

• An analytical method of MA and its main metabolite in fingermark was developed.
• The influence factors for the detection of MA in fingermark were discussed.
• The effect of development methods to the test of MA and AM in fingermark was tested.

A sensitive and efficient method applying liquid chromatography–mass spectrometry for the analysis of methamphetamine and its main metabolite in fingermark deposits was described. Using this method, good linear relationship of methamphetamine was obtained in the range of 0.005 μg to 0.5 μg per cotton swab, the limit of detection was 1.5 ng per cotton swab, the limit of quantitation was 5.0 ng per cotton swab and the average values of recovery ratios were above 70.1%. Moreover, the influence factors for the detection of methamphetamine in fingermarks, such as kinds of substrates, development methods and extraction methods, were all discussed in details. The results showed that good recovery ratios could be obtained on painted wood and smooth substrates surfaces. Development methods in commercial powder could not influence the quality of examination of exogenous drug in latent fingermark. Furthermore, the results indicated that the method mentioned here could be applied in the analysis of forensic trace evidences and samples obtained in clinically addicted cases.