A flow potentiometric method for determination of caffeine in saliva is suggested. This task is important for non-invasive assessment of drug metabolizing system activity in hepatocytes. In the current study, stepwise injection analysis (SWIA) was successfully combined with single-drop liquid microextraction (SDLME) and solvent exchange procedure. The method is based on the caffeine SDLME with subsequent solvent evaporation and dissolution of analyte in sulfuric acid followed by potentiometric detection using poly(vinyl chloride) membrane electrode containing potassium tetrakis[3,5-bis(trifluoromethyl)phenyl]borate as electroactive component. SDLME was employed for elimination of interfering matrix effects of saliva and caffeine metabolites such as theophylline, theobromine and paraxanthine. A linear range of 10(-5)-10(-2)M was established for caffeine with detection limit at 6 × 10(-6)M. The sample throughput was 6 samples h(-1). The proposed method was successfully applied to the determination of caffeine in saliva and the analytical results agreed well with the results obtained with reference HPLC method.
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http://dx.doi.org/10.1016/j.talanta.2016.01.001 | DOI Listing |
Arch Microbiol
January 2025
School of Basic and Applied Sciences, Department of Biological Sciences, Dayananda Sagar University, Innovation Campus, Kudlu Gate, Hosur Rd, Bengaluru, 560 068, India.
To explore the mechanistic underpinnings of caffeine as a potent antibacterial against Staphylococcus aureus ATCC 25923 via in vitro functional assays, whole-genome sequencing, and in silico docking studies. In vitro studies established that caffeine's minimum inhibitory concentration (MIC) against S. aureus ATCC 25923 is 0.
View Article and Find Full Text PDFFood Res Int
January 2025
Department of Agricultural Chemistry and Food Science, Faculty of Science, C/ Francisco Tomás y Valiente, 7, Universidad Autónoma de Madrid, 28049 Madrid, Spain; Department of Production and Characterization of Novel Foods, Institute of Food Science Research, CIAL (UAM-CSIC), 28049 Madrid, Spain. Electronic address:
Coffee pulp (CP) is the by-product of coffee processing that urgently needs to be revalorized using sustainable technologies. This work applied a design of experiment (DoE) for modeling the extraction of bioactive compounds from CP using supercritical carbon dioxide (sc-CO) with ethanol as a co-solvent under variable conditions (temperature, pressure, and ethanol percentage). Considering extraction efficiency (per unit of CP) and extraction selectivity (per unit of extract), results showed that ethanol percentage significantly enhanced the efficiency of total phenolic content, as well as the selectivity of chlorogenic acid and protocatechuic acid (p < 0.
View Article and Find Full Text PDFFood Chem Toxicol
January 2025
Military Nutrition Division, US Army Research Institute of Environmental Medicine, Natick, MA, USA. Electronic address:
Caffeine is a popular stimulant, predominantly consumed from beverages. The caffeinated beverage marketplace is continually evolving resulting in considerable interest in understanding the impact caffeinated beverages have on levels of intakes. Therefore, estimates of caffeine intakes in the U.
View Article and Find Full Text PDFEnviron Geochem Health
January 2025
School of Civil Engineering, Vellore Institute of Technology, Tamil Nadu, Vellore, 632014, India.
Urban environments are heavily influenced by various activities, leading to contamination of water sources by emerging contaminants (ECs). Among these, caffeine (CAF) and N, N-diethyl-meta-toluamide (DEET) are notable ECs frequently found in domestic sewage due to human activities. Despite extensive research on emerging contaminants, limited studies have focused on the seasonal variations, human health and ecological risks of CAF and DEET in urban groundwater, particularly in Indian cities.
View Article and Find Full Text PDFMass Spectrom (Tokyo)
December 2024
Graduate School of Engineering, Osaka University, A1/A14, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan.
Mass spectrometry (MS) is a valuable tool that enables label-free analysis and the ability to measure multiple molecules. The atmospheric pressure MS imaging (MSI) method usually requires tedious sample preparation. A simple ionization method with minimal sample preparation is needed for high-throughput analysis.
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