Development and validation of a diode array high performance liquid chromatography method to determine seized street cocaine sample purity

Abstract

A novel, precise, specific, accurate and rapid reversed-phase high performance liquid chromatographic method, with diode array detection, was developed, optimized and validated to determine the drug purity of cocaine street samples seized in Italy and to characterize the adulterants. The method was performed using a C18 column, under isocratic conditions, with potassium phosphate buffer–acetonitrile as the mobile phase, at 232 nm. Linearity was studied from 0.01 to 0.50 mg mL−1, with a determination coefficient (r2) higher than 0.9999. The limit of detection (LOD) and limit of quantification (LOQ) were 0.004 mg mL−1 and 0.01 mg mL−1, respectively. Precision was evaluated as repeatability and intermediate precision with relative standard deviations not exceeding 5%. Validation of the HPLC method was carried out following ICH guidelines. Also, the estimation of the uncertainty measurements was included. The proposed HPLC-DAD method was thus shown to be convenient and highly suitable for the routine analysis of seized samples of drugs of abuse

Carbon nanotube β-cyclodextrin-modified electrode for quantification of cocaine in seized street samples

“…Separation was performed on a prepacked Nucleosil 100-5 C18, analytical column (250 mm × 4.6 mm, 5 μm, Macherey-Nagel, Duren, Germany), and the mobile phase was 0.02 M phosphate buffer (pH 6.5)-acetonitrile (65:35, v/v). It was delivered isocratically at 1.0 mL min −1 at room temperature [23,24]. The chromatographic data was processed using the software package LabSolutions (Shimadzu, Japan).…”

“…Quantification of the sample concentration was performed by interpolation from the analytical curve. The accuracy of the proposed method was determined by comparing the results with those obtained from a previously published HPLC method [24]. Additionally, the possible interference of some adulterants, commonly added to cocaine street samples to maximise profit, was evaluated.…”

“…For comparison purposes, the content of cocaine was also measured using a reference HPLC method [23,24]. Five independent measurements were carried out, for both the LSV and the HPLC methods.…”

Micro-HPLC–UV analysis of cocaine and its adulterants in illicit cocaine samples seized by Austrian police from 2012 to 2017

“…Since a long time, approaches to develop methods for simultaneous separation and quantification of cocaine adulterants by gas chromatography and HPLC were presented in the literature for both seized material [3,4] and biological matrices. [5] In 2013, Brancaccio et al [6] introduced an HPLC method for samples seized in Italy. They used an isocratic method and a standard bore (4.6 mm) RP-18 column by analyte detection at 232 nm.…”

“…In the sequel, cocaine, caffeine, procaine, levamisole, phenacetin, and lidocaine were analyzed within 13 min. [6] In contrary to the aforementioned citation, Floriani's group used a binary gradient consisting of (A) acetonitrile and (B) aqueous ammonium formate 0.05M-pH 3.1 for the determination of main adulterants found in products based on cocaine. [7] Later, another Italian group reported on analysis of recent drug seizures in Italy with respect to their purity and adulterant content.…”