Evaluation of mepiquat in malted barley and beer using LC-MS/MS

Abstract

Following recent studies that showed that the agrochemical mepiquat (1,1-dimethylpiperidinium) forms during the roasting of coffee beans and barley, this work investigates the presence of mepiquat in malted barley and commercially available beers. Liquid chromatography–tandem mass spectrometry was used to develop a sensitive and precise analytical method, with detection limits of 0.031 ng/g in malted barley and 0.014 ng/g in beer. Mepiquat was detected in nine out of 10 malted barley samples, with all results under the Canadian maximum residue limit (100 ng/g). The data suggest a relationship between perceived malted barley colour and mepiquat concentration. The concentration of mepiquat in the beers analysed was also below the maximum residue limits in Canada (100 ng/g) and in the EU (600 ng/g), suggesting that mepiquat is not a regulatory concern in finished beers. Copyright © 2015 The Institute of Brewing & Distilling