Esters-targeted colorimetric sensor array for the authenticity discrimination of strong-aroma baijiu with different origins.

Baijiu authenticity has been a frequent problem driven by economic interests in recent years, so it is important to discriminate against baijiu with different origins. Herein, we proposed a simple and efficient esters-targeted colorimetric sensor array mediated by hydroxylamine hydrochloride. Esters undergo a nucleophilic addition reaction with hydroxylamine hydrochloride to form hydroxamic acid, which rapidly forms a purplish red ferric hydroxamate under FeCl 3 ·6H 2 O. Bromophenol blue and rhodamine B enrich the color effects. The array detected 12 esters with a detection limit on the order of 10−5 of most esters and 16 mixed esters with R2 > 0.999 and recoveries close to 100%. Otherwise, for discriminating 34 strong-aroma baijius (SABs), the array has an accuracy of 98% according to the origin, and 95% according to the grades, with a response time of 1 min. This study provides a new strategy for authenticity determination and quality control of baijiu. [Display omitted] • A novel esters-targeted colorimetric sensor array was proposed. • PSO-VWLS-SVM was used to analyze mixed esters. • 8 origins of 34 strong-aroma baijius were discriminated by the array with an accuracy of 98%. • The detection time of the sensor array is 1 min. [ABSTRACT FROM AUTHOR]