Extraction-Free, Direct Determination of Caffeine in Microliter Volumes of Beverages by Thermal Desorption-Gas Chromatography Mass Spectrometry

Abstract

An extraction-free method requiring microliter (μL) 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 μL 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 μg/mL (R2 = 0.996). The theoretical limit of detection (3 σ) was 0.456 μg/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.

Caffeine quantification in dietary supplements using high-throughput on-line solid phase extraction coupled to Venturi easy ambient sonic-spray ionization mass spectrometry

“…Consequently, the accurate quantication of caffeine in dietary supplements is essential to prevent potential health risks. 25 For years, the determination of caffeine has been performed using different analytical techniques such as HPLC, 26,27 gas chromatography (GC-MS), 28 and HPLC coupled with tandem mass spectrometry (MS/MS). 29,30 However, the use of AIMS for caffeine quantication, for example with paper spray mass spectrometry (PS-MS), 31 presents a promising alternative to traditional analytical techniques such as HPLC and GC, by providing rapid and sensitive detection while minimizing sample preparation.…”

Quantitative Analysis of Caffeine in the Green Tea, Black Tea and Soft Drink Using UV-Visible Spectrophotometer

“…Several chemical and physical methods have been developed for the determination of caffeine in coffee and other beverages. The most widely used methods for the determination of caffeine in beverages include various analytical techniques such as Fourier Transform infrared, (12) Raman spectroscopy, (13) UV Visible spectrophotometer, (14)(15)(16) HPLC, (17,18) GC with mass (19,20) . In the present paper the UV Visible spectrophotometer is used to quantify the caffeine in various beverages since it is a cheap, economic and fast method.…”

Analytical Separation Method: A Student’s Perception on Analogy-based Teaching for Terminology

“…Knowledge of the separation method has been successfully applied in many leading research studies, such as food (Janelle et. al., 2015;Peng et al, 2020), antioxidants (Ma et al, 2020), and drug delivery (Ruz et. al., 2004;Tekkeli & Kiziltas, 2016).…”