Fast Quantitative Detection of Cocaine in Beverages Using Nanoextractive Electrospray Ionization Tandem Mass Spectrometry

Without any sample pretreatment, effervescent beverage fluids were manually sprayed into the primary ion plume created by using a nanoelectrospray ionization source for direct ionization, and the analyte ions of interest were guided into an ion trap mass spectrometer for tandem mass analysis. Functional ingredients (e.g., vitamins, taurine, and caffeine, etc.) and spiked impurity (e.g., cocaine) in various beverages, such as Red Bull energy drink, Coco-cola, and Pepsi samples were rapidly identified within 1.5 s. The limit of detection was found to be 7 ∼ 15 fg (S/N = 3) for cocaine in different samples using the characteristic fragment (m/z 150) observed in the MS³ experiments. Typical relative standard deviation and recovery of this method were 6.9% ∼ 8.6% and 104% ∼ 108% for direct analysis of three actual samples, showing that nanoextractive electrospray ionization tandem mass spectrometry is a useful technique for fast screening cocaine presence in beverages.