Development of an electroanalytical method for the quantification of aminopyrine in seized cocaine samples

• Aminopyrine (AM) is used in the adulteration of cocaine samples.
• First non-modified sensor for AM quantification in cocaine samples
• Accurate analysis without interference of other adulterants to drugs of abuse
• The proposed method is simple and suitable for routine applications.
• Application in analysis for forensic intelligence purposes

We report the development of a simple and accurate analytical method to detect aminopyrine in seized cocaine samples using a platinum electrode. The quantification of aminopyrine was performed using square wave voltammetry (SWV), where the peak current response was found to increase linearly with aminopyrine concentration over the range 100–1000 μmol L− 1. The repeatability of the electrode response was determined to be 2.4% (n = 15), and the detection limit of the proposed method was estimated to be 22 μmol L− 1 (3σ/slope). The accuracy of the proposed method was evaluated comparing the measured aminopyrine concentration in seized cocaine sample to the value obtained by gas chromatography coupled to flame ionization detector (GC-FID). An addition and recovery protocol in seized cocaine samples was also performed.