Skip to Content
MilliporeSigma
  • Determination of levamisole and tetramisole in seized cocaine samples by enantioselective high-performance liquid chromatography and circular dichroism detection.

Determination of levamisole and tetramisole in seized cocaine samples by enantioselective high-performance liquid chromatography and circular dichroism detection.

Journal of chromatography. A (2014-08-16)
Carlo Bertucci, Daniele Tedesco, Edoardo Fabini, Anna Maria Di Pietra, Francesca Rossi, Marco Garagnani, Elia Del Borrello, Vincenza Andrisano
ABSTRACT

Levamisole, an anthelmintic drug, has been increasingly employed as an adulterant of illicit street cocaine over the last decade; recently, the use of tetramisole, the racemic mixture of levamisole and its enantiomer dexamisole, was also occasionally observed. A new enantioselective high-performance liquid chromatography (HPLC) method, performed on cellulose tris(3,5-dimethylphenylcarbamate) chiral stationary phases in normal-phase mode, was validated to determine the enantiomeric composition of tetramisole enantiomers in seized cocaine samples. Furthermore, the hyphenation of the validated HPLC method with a circular dichroism (CD) detection system allowed the direct determination of elution order and a selective monitoring of levamisole and dexamisole in the presence of possible interferences. The method was applied to the identification and quantitation of the two enantiomers of tetramisole in seized street cocaine samples.

MATERIALS
Product Number
Brand
Product Description

Sigma-Aldrich
Ethanol, ≥99.5%
Sigma-Aldrich
Caffeine, SAJ special grade, ≥98.5%
Sigma-Aldrich
Ethanol, ≥99.5%, suitable for HPLC
Sigma-Aldrich
Diethylamine, SAJ special grade, ≥99.0%
Sigma-Aldrich
Ethanol, ≥99.5%, suitable for fluorescence
Sigma-Aldrich
Diethylamine, SAJ first grade, ≥98.0%
Sigma-Aldrich
Ethanol, JIS 300, ≥99.5%, for residue analysis
Sigma-Aldrich
Ethanol, ≥99.5%, SAJ super special grade
Sigma-Aldrich
Hexane, suitable for HPLC
Sigma-Aldrich
Caffeine, anhydrous, 99%, FCC, FG
Sigma-Aldrich
Diethylamine, ≥99.5%
Sigma-Aldrich
Ethyl alcohol, Pure, 200 proof, anhydrous, ≥99.5%
Supelco
Caffeine, Pharmaceutical Secondary Standard; Certified Reference Material
Supelco
2-Propanol, Pharmaceutical Secondary Standard; Certified Reference Material
Sigma-Aldrich
Ethanol, JIS 1000, ≥99.5%, for residue analysis
Sigma-Aldrich
Ethanol, ≥99.5%, suitable for absorption spectrum analysis
Supelco
Caffeine Melting Point Standard, Pharmaceutical Secondary Standard; Certified Reference Material
Sigma-Aldrich
Ethyl 4-aminobenzoate, 98%
Supelco
Caffeine, certified reference material, TraceCERT®, Manufactured by: Sigma-Aldrich Production GmbH, Switzerland
USP
Caffeine melting point standard, United States Pharmacopeia (USP) Reference Standard
Sigma-Aldrich
Cocaine free base
Sigma-Aldrich
Caffeine, Sigma Reference Standard, vial of 250 mg
Supelco
Ethanol standards 10% (v/v), 10 % (v/v) in H2O, analytical standard
Sigma-Aldrich
Caffeine, powder, ReagentPlus®
Sigma-Aldrich
Caffeine, BioXtra
Sigma-Aldrich
Caffeine, meets USP testing specifications, anhydrous
Sigma-Aldrich
Ethyl alcohol, Pure, 190 proof, ACS spectrophotometric grade, 95.0%
Sigma-Aldrich
Diethylamine, purified by redistillation, 99.5%
Supelco
Mettler-Toledo Calibration substance ME 18872, Caffeine, traceable to primary standards (LGC)
Caffeine, European Pharmacopoeia (EP) Reference Standard