%0 Journal Article
%T Extraction-Free, Direct Determination of Caffeine in Microliter Volumes of Beverages by Thermal Desorption-Gas Chromatography Mass Spectrometry
%A Bowdler
%A Paul
%A Brown
%A Melanie
%A Honeychurch
%A Kevin C.
%A Peng
%A Xianglu
%J -
%D 2020
%R https://doi.org/10.1155/2020/5405184
%X An extraction-free method requiring microliter (¦ÌL) volumes has been developed for the determination of caffeine in beverages. Using a pyrolysis-gas chromatography mass spectrometry system, the conditions required for the direct thermal desorption-gas chromatography mass spectrometry (TD-GC/MS) determination of caffeine were optimised. A 5£¿¦ÌL aliquot was introduced to the thermal desorption unit, dried, and thermally desorbed to the GC/MS. The response was linear over the range 10 to 500£¿¦Ìg/mL (R2£¿=£¿0.996). The theoretical limit of detection (3 ¦Ò) was 0.456£¿¦Ìg/mL. No interferences were recorded from endogenous beverage components or from commonly occurring drugs, such as nicotine, ibuprofen, and paracetamol. Replicate caffeine determinations on fortified latte style white coffee and Pepsi Max£¿ gave mean recoveries of 93.4% (%CV£¿=£¿4.1%) and 95.0% (%CV£¿=£¿0.98%), respectively. Good agreement was also obtained with the stated values of caffeine for an energy drink and for Coca-Cola£¿. These data suggest that the method holds promise for the determination of caffeine in such samples
%U https://www.hindawi.com/journals/ijac/2020/5405184/