Classification of Narcotics in Solid Mixtures Using Principal Component Analysis and Raman Spectroscopy

Ryder, Alan G.

doi:10.1520/jfs15244j

Cited by 74 publications

(57 citation statements)

References 27 publications

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“…It has been used for the discrimination of simulated street drugs, such as cocaine, heroin and MDMA (ecstasy). [5][6][7] More recently, Raman spectra have also been used for quantitative analysis of simulated street drugs. 8 In addition, other two articles also employed attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) and diffuse reflectance near infrared spectroscopy (NIRS) for quantitative analysis of simulated samples of methylamphetamine and diacetylmorphine (heroin), respectively.…”

mentioning

confidence: 99%

Analysis of seized cocaine samples by using chemometric methods and FTIR spectroscopy

Rodrigues¹,

Cardoso²,

Andrade³

et al. 2013

J. Braz. Chem. Soc.

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O objetivo deste trabalho foi desenvolver uma metodologia quimiométrica para descrever o perfil químico de amostras de cocaína apreendidas no estado de Minas Gerais (Brasil). A identificação de adulterantes e a quantificação do teor de cocaína foram feitas por cromatografia gasosa acoplada à espectrometria de massa (GC-MS). Espectros de 91 amostras foram obtidos por espectroscopia no infravermelho usando refletância total atenuada (ATR-FTIR), e utilizados na construção de um modelo de análise de componentes principais (PCA). A primeira componente principal (PC1) discriminou as amostras de maior pureza das mais diluídas/adulteradas, nas quais foram identificadas lidocaína, cafeína e benzocaína. PC2 discriminou a forma química da cocaína, cloridrato ou base. Além disso, dois modelos supervisionados discriminantes (mínimos quadrados parciais para análise discriminante, PLS-DA) foram desenvolvidos para classificar as amostras em função de sua diluição (abaixo e acima de 15% m/m) e de sua forma química, apresentando taxas de acerto que variaram entre 83 e 97%. Os modelos de classificação constituem uma ferramenta simples, rápida e não destrutiva, de grande valor para peritos forenses e investigadores criminais.The aim of this article was to develop a chemometric methodology for determining the chemical profile of cocaine samples seized in Minas Gerais State, Brazil. The adulterant detection and the cocaine determination were performed by gas chromatography-mass spectrometry (GC-MS). Spectra of 91 samples were obtained by attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) and used to build an exploratory principal component analysis (PCA) model. The first principal component (PC1) discriminated samples of more purity from the more diluted/adulterated ones, which were characterized by the presence of lidocaine, caffeine and benzocaine. PC2 discriminated the two chemical forms of cocaine, hydrochloride and base. In addition, two supervised discriminant partial least-squares models (partial least-squares discriminant analysis, PLS-DA) were developed for classifying the samples according to dilution (above and below 15% m/m) and chemical form, with a rate of success that varied between 83 and 97%. The classification models constitute a simple, rapid and non-destructive tool, of great value for both forensic experts and criminal investigators. Keywords: illicit drugs, MID infrared, principal component analysis, cocaine, chemometrics IntroductionCocaine is an alkaloid extracted from plants of the genera Erythroxylum (E. novagranatense and E. coca). United Nations Office on Drugs and Crime (UNODC) considers cocaine, after heroin, the second most problematic drug worldwide in terms of negative health consequences and probably the most problematic drug in terms of trafficking-related violence. Estimates suggest that 440 t of pure cocaine were consumed in the world in 2009, which would be in line with a total production estimate of 1,111 t, wholesale purity-adjusted seizures Analysis of Seized Cocain...

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confidence: 99%

Analysis of seized cocaine samples by using chemometric methods and FTIR spectroscopy

Rodrigues¹,

Cardoso²,

Andrade³

et al. 2013

J. Braz. Chem. Soc.

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“…There still remain two drugs for which very little Raman data has been reported, namely, heroin [20,21] and cannabis. These are two drugs-of-abuse whose detection and identification remain highly important to law enforcement and customs agencies.…”

Section: Resultsmentioning

confidence: 99%

“…[23] PCA is a statistical technique that is well used in Raman spectroscopy and vibrational spectroscopy in general. [10,21,24] It is used to identify the underlying structure of large datasets with the aim of identifying groups within the data while at the same time removing any contribution from noise. Pre-processing of the data was performed to reduce inherent noise within the spectra from instrumental or sample variability.…”

Section: Chemometric Data Analysismentioning

confidence: 99%

Comparison of near infrared laser excitation wavelengths and its influence on the interrogation of seized drugs‐of‐abuse by Raman spectroscopy

Hargreaves

Burnett

Munshi

et al. 2009

J Raman Spectroscopy

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aThe laser excitation wavelength is an important parameter in obtaining Raman spectra from drugs-of-abuse. This article compares the effect of near infrared wavelengths, 785 nm, using both benchtop and portable instrumentation and benchtop 1064 nm on the Raman spectra of seized drugs-of-abuse, including cocaine hydrochloride, cocaine freebase (crack), methylenedioxymethamphetamine ('ecstasy'), amphetamine, diamorphine (heroin) and cannabis. The significant benefit of using 1064 nm for the interrogation of this type of sample is highlighted.

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“…Details of relevant algorithms for both iPCA and siPCA can be found in [4]. In the field of forensic science, PCA is a popular exploratory and dimensionality reduction technique [6][7][8][9]. However, there is a lack of literature on the application of the aforementioned variants of PCA in forensic analysis.…”

Section: Introductionmentioning

confidence: 99%

Comparison of several variants of principal component analysis (PCA) on forensic analysis of paper based on IR spectrum

Lee¹,

Liong²,

Osman³

et al. 2016

AIP Conference Proceedings

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Classification of Narcotics in Solid Mixtures Using Principal Component Analysis and Raman Spectroscopy

Cited by 74 publications

References 27 publications

Analysis of seized cocaine samples by using chemometric methods and FTIR spectroscopy

Analysis of seized cocaine samples by using chemometric methods and FTIR spectroscopy

Comparison of near infrared laser excitation wavelengths and its influence on the interrogation of seized drugs‐of‐abuse by Raman spectroscopy

Comparison of several variants of principal component analysis (PCA) on forensic analysis of paper based on IR spectrum

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