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Summary
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This study analyzed 513 cocaine seizures using Fourier transform infrared spectroscopy (FT-IR) and chemometrics. Researchers identified common adulterants like caffeine, lidocaine, and phenacetin in cocaine base and salt samples.

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Area of Science:

  • Forensic Chemistry
  • Analytical Chemistry
  • Spectroscopy

Background:

  • Cocaine adulteration is a significant public health concern.
  • Understanding adulterant profiles aids in forensic investigations and policy development.
  • Fourier Transform Infrared Spectroscopy (FT-IR) is a powerful tool for chemical analysis.

Purpose of the Study:

  • To profile and identify pharmaceutical adulterants in cocaine seizures.
  • To differentiate between cocaine base and cocaine salt using spectroscopic data.
  • To evaluate the effectiveness of chemometric methods for cocaine analysis.

Main Methods:

  • Analysis of 513 cocaine seizures from Rio Grande do Sul, Brazil, using FT-IR spectroscopy.
  • Application of Hierarchical Cluster Analysis (HCA) and Principal Component Analysis (PCA) for pattern recognition.
  • Utilized Partial Least Square Discriminant Analysis (PLS-DA) and Support Vector Machines Discriminant Analysis (SVM-DA) for classification.

Main Results:

  • Cocaine samples were accurately grouped into base and salt categories by HCA and PCA.
  • Cocaine salt samples were predominantly adulterated with caffeine and lidocaine.
  • Cocaine base samples were consistently adulterated with phenacetin.

Conclusions:

  • FT-IR spectroscopy combined with chemometrics effectively profiles cocaine seizures and identifies adulterants.
  • Distinct adulteration patterns were observed for cocaine base versus cocaine salt.
  • PLS-DA and SVM-DA demonstrated high accuracy in classifying cocaine base and salt.