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Full-Text Articles in Chemistry

Three-Way Analysis-Based Ph-Uv-Vis Spectroscopy For Quantifying Allura Red In An Energy Drink And Determining Colorant's Pka, Erdal Dinç Prof., Nazangül Ünal, Zehra Ceren Ertekin Mar 2021

Three-Way Analysis-Based Ph-Uv-Vis Spectroscopy For Quantifying Allura Red In An Energy Drink And Determining Colorant's Pka, Erdal Dinç Prof., Nazangül Ünal, Zehra Ceren Ertekin

Journal of Food and Drug Analysis

Three-way analysis-based pH-UV-Vis spectroscopy was proposed for quantifying allura red in an energy drink product without the need for chromatographic analysis, and determining the colorant’s pKa without using any titration technique. In this study, UV-Vis spectroscopic data matrices were obtained from absorbance measurements at five different pH levels from pH 8 to pH 12 and arranged as a three-way array (wavelength x sample x pH). In the three-way analysis procedure, parallel factor analysis (PARAFAC) was implemented to decompose the three-way array into a set of trilinear components. Each set of three components relates to spectral, pH and relative concentration profiles …


The Analytical And Biomedical Applications Of Carbon Dots And Their Future Theranostic Potential: A Review, Sukunya Ross, Ren-Siang Wu, Shih-Chun Wei, Gareth M. Ross, Huan-Tsung Chang Dec 2020

The Analytical And Biomedical Applications Of Carbon Dots And Their Future Theranostic Potential: A Review, Sukunya Ross, Ren-Siang Wu, Shih-Chun Wei, Gareth M. Ross, Huan-Tsung Chang

Journal of Food and Drug Analysis

In recent years, carbon dots (C-dots) have gained appreciable interest owing to their unique optical properties, including tunable fluorescence, stability against photobleaching and photoblinking, and strong fluorescence. Simple and low-cost hydrothermal and electrochemical approaches have been widely used in the preparation of biocompatible and high-quality C-dots. Various C-dots have been used for the quantitation of small analytes, mostly based on analyte induced fluorescence quenching. Depending on the nature of precursors, synthetic conditions (such as reaction temperature and time), and surface conjugation, multi-function C-dots can be prepared and used in diagnostics and therapeutics. Their strong fluorescence and photostability, enables use in …


Detection Of Melamine Based On The Suppressed Anodic Response Of Uric Acid By A Au-Ag Nanoparticles Modified Glassy Carbon Electrode, Yu-Hui Peng, Tsunghsueh Wu, Yang-Wei Lin Aug 2020

Detection Of Melamine Based On The Suppressed Anodic Response Of Uric Acid By A Au-Ag Nanoparticles Modified Glassy Carbon Electrode, Yu-Hui Peng, Tsunghsueh Wu, Yang-Wei Lin

Journal of Food and Drug Analysis

We demonstrated a sensitive electrochemical method for the determination of non-electroactive melamine (Mel) using a modified glassy carbon electrode (GCE), with uric acid (UA) as the signal reporter. To increase the anodic response of UA, GCE was coated with Au–Ag nanoparticles and a Nafion thin film (Au–Ag/Nafion/GCE). The sensing mechanism was based on the competitive adsorption behavior of Mel on the Au–Ag/Nafion/GCE, which reduces the electroactive surface area of nanoparticles and thus hinders anodic response of UA. Under optimal conditions and the use of an analytical method of differential pulse voltammetry, this modified electrode detected Mel concentrations ranging from 2.5 …


Spatiotemporal Patterns Of Polychlorinated Dibenzo-P-Dioxins And Dibenzofurans And Dioxin-Like Polychlorinated Biphenyls In Foodstuffs In Air Quality Regions In Taiwan, Ching-Chang Lee, Wei-Hsiang Chang, Hsin-Tang Lin, Jung-Wei Chang Aug 2020

Spatiotemporal Patterns Of Polychlorinated Dibenzo-P-Dioxins And Dibenzofurans And Dioxin-Like Polychlorinated Biphenyls In Foodstuffs In Air Quality Regions In Taiwan, Ching-Chang Lee, Wei-Hsiang Chang, Hsin-Tang Lin, Jung-Wei Chang

Journal of Food and Drug Analysis

High-fat food intake is the main source of dioxin-like compounds for humans, such as consumption of meat, dairy and eggs, and seafood products. Fruits, vegetables, and cereals have relatively low levels of dioxin-like compounds, but because of high consumption they also contribute to the food-borne intake. It is necessary to clarify dietary dioxin exposure affected by different food contamination levels and dietary habits among different geographic areas. We aimed to evaluate chronic dietary PCDD/Fs and DL-PCBs exposure in 725 individual foods in 14 categories in 6 Taiwan air quality regions (AQRs) and a total of 2,441 foods from 2004 and …