Statistical comparison of mass spectra for identification of amphetamine-type stimulants.
Forensic Sci Int
; 270: 111-120, 2017 Jan.
Article
en En
| MEDLINE
| ID: mdl-27936426
ABSTRACT
A method for the statistical comparison of mass spectral data is demonstrated for applications in controlled substance analysis. The method uses an unequal variance t-test at each mass-to-charge ratio in the scan range to determine if two spectra are statistically associated or discriminated. If the two spectra are associated, a random-match probability is calculated to estimate the likelihood that the mass spectral fragmentation pattern in question occurs by random chance alone. If the two spectra are discriminated, the fragment ions responsible for the discrimination are determined. In this work, mass spectral data from case samples containing amphetamine, methamphetamine, 3,4-methylenedioxyamphetamine (MDA), 3,4-methylenedioxymethamphetamine (MDMA), phentermine, and psilocin were investigated. All spectra were collected in an accredited forensic laboratory using routine methods for controlled substance analysis. Using the statistical method, spectra of case samples were statistically associated to the corresponding reference standard at the 99.9% confidence level. In these instances, random-match probabilities ranged from 10-39 to 10-29, indicating the probability that the characteristic fragmentation pattern occurred by random chance is extremely small. Further, spectra of case samples were discriminated from other reference standards at the 99.9% or 99.0% confidence level, with 1-26 ions responsible for discrimination in each comparison.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Espectrometría de Masas
/
Estadística como Asunto
/
Anfetaminas
/
Estimulantes del Sistema Nervioso Central
Tipo de estudio:
Diagnostic_studies
/
Prognostic_studies
Límite:
Humans
Idioma:
En
Revista:
Forensic Sci Int
Año:
2017
Tipo del documento:
Article
País de afiliación:
Estados Unidos