Uso de ressonância magnética nuclear sem solvente deuterado (No-D NMR) para análise de cocaína e seus adulterantes

Abstract

Analysisofillicit drugs are mainly performingbyanalyticaltechniques such asgas Chromatography coupled withMass Spectrometry(GC/MS) or with flame ionization detector (GC/FID) and Infrared Spectroscopy (IR). Other non-conventional techniques for drugs analysis, because of the spectrometer costand low sensitivity, are now becomingviableforanalysisof these samples. An example isNuclear Magnetic Resonance (NMR), duetothe larger amount ofsample andthe high cost ofdeuterated solventsemployedin solution samplesbecameNMRtechniquewith a highaddedvalue.In this work, NMR studies were performingwithout the use of deuterated solvent in the dilution of samples of cocaine seized by the State Civil Police of Espirito Santo, called No-D NMR. The application of this technique reduces the cost of analysis since deuterated compounds are not usingas the solvent. As this was a new method of analysis was optimized acquisition parameters and processing characteristic of NMR. The spectral quality obtained allowed separation of the characteristic signs of cocaine and its major adulterants: caffeine,phenacetin and lidocaine.A second step of this work was the application of figures of merit to validate the No-D NMR as a new methodology to quantify cocaine and its main adulterants. Studies of specificity/selectivity, linearity, limit of detection (LOD), limit of quantification (LOQ), and accuracy/precision were performingand showed that the proposed methodology is adequate to quantify cocaine and its adulterants in seizures. After obtaining the "figures of merit", was quantified 29 seizures that had a low amount of cocaine (about 24% w/w) which demonstrated that occurs much adulterationof samples sold in the Espirito Santo