Portable analytical platforms associated with chemometrics for rapid screening of whisky adulteration

Abstract

Adulteration of alcoholic beverages is a worldwide concern for authorities, mainly due to risks to human health. This report describes the use of portable analytical platforms combined with chemometrics to trace the authenticity profile of whisky. Rapid analysis by miniaturized methodologies based on separation and colorimetric reactions as well as pH and conductivity measurements is proposed as a strategy for forensic screening at the point of need. Anionic profiles of whisky were obtained using a microchip electrophoresis system with integrated contactless conductivity detection. The indirect detection of caramel and the determination of alcohol content were performed by colorimetric reactions on paper-based analytical devices, which were explored in single microzones and foldable devices, respectively. These methodologies were successfully applied to a total of 50 whisky samples, 45 of which were adulterated and 5 authentic. A correlation study involving these markers and their analytical response through different techniques was then performed. A chemometric tool employing all these parameters was able to distinguish more than 90% of adulterated samples from authentic ones, demonstrating that the proposed methodology is effective for mapping whisky samples. These portable methods have great potential for use at the site of apprehension, due to the low consumption of samples and speed of analysis.