Asturias-Arribas Laura, Alonso-Lomillo M Asunción, Domínguez-Renedo Olga, Arcos-Martínez M Julia
Analytical Chemistry Department, Faculty of Sciences, University of Burgos, Pza. Misael Bañuelos s/n, 09001 Burgos, Spain.
Analytical Chemistry Department, Faculty of Sciences, University of Burgos, Pza. Misael Bañuelos s/n, 09001 Burgos, Spain,.
Anal Chim Acta. 2014 Jun 27;834:30-6. doi: 10.1016/j.aca.2014.05.012. Epub 2014 May 17.
This paper describes the voltammetric determination of cocaine in presence of three different interferences that could be found in street samples using disposable sensors. The electrochemical analysis of this alkaloid can be affected by the presence of codeine, paracetamol or caffeine, whose oxidation peaks may overlap and lead to false positives. This work describes two different solutions to this problem. On one hand, the modification of disposable carbon sensors with carbon nanotubes allows the voltammetric quantification of cocaine by using ordinary least squares regressions in the concentration range from 10 to 155 μmol L(-1), with a reproducibility of 5.6% (RSD, n = 7. On the other hand, partial least squares regressions are used for the resolution of the overlapped voltammetric signals when using screen-printed carbon electrodes without any modification. Both procedures have been successfully applied to the evaluation of the purity of cocaine street samples.
本文描述了使用一次性传感器伏安法测定街头样本中可卡因的方法，该样本中存在三种不同的干扰物质。这种生物碱的电化学分析可能会受到可待因、对乙酰氨基酚或咖啡因的影响，它们的氧化峰可能会重叠并导致假阳性。这项工作描述了针对该问题的两种不同解决方案。一方面，用碳纳米管修饰一次性碳传感器，通过普通最小二乘法回归，可在10至155 μmol L(-1)浓度范围内对可卡因进行伏安定量，重现性为5.6%（相对标准偏差，n = 7）。另一方面，在使用未经任何修饰的丝网印刷碳电极时，采用偏最小二乘法回归来解析重叠的伏安信号。这两种方法均已成功应用于评估街头可卡因样本的纯度。
