title: Quantitative SERS analysis of azorubine (E 122) in sweet drinks.
abstract: Considering both the potential effects on human health and the need for knowledge of food composition, quantitative detection of synthetic dyes in foodstuffs and beverages is an important issue. For the first time, we report a fast quantitative analysis of the food and drink colorant azorubine (E 122) in different types of beverages using surface-enhanced Raman scattering (SERS) without any sample preparation. Seven commercially available sweet drinks (including two negative controls) with high levels of complexity (sugar/artificial sweetener, ethanol content, etc.) were tested. Highly uniform Au "film over nanospheres" (FON) substrates together with use of Raman signal from silicon support as internal intensity standard enabled us to quantitatively determine the concentration of azorubine in each drink. SERS spectral analysis provided sufficient sensitivity (0.5-500 mg L(-1)) and determined azorubine concentration closely correlated with those obtained by a standard HPLC technique. The analysis was direct without the need for any pretreatment of the drinks or Au surface. Our SERS approach is a simple and rapid (35 min) prescan method, which can be easily implemented for a field application and for preliminary testing of food samples.
authors: Institute of Physics, Faculty of Mathematics and Physics, Charles University in Prague , Ke Karlovu 5, 121 16 Prague 2, Czech Republic.
authors: Vlastimil
authors: V
authors: Peksa
authors: Martin
authors: M
authors: Jahn
authors: Lucie
authors: L
authors: Štolcová
authors: Volker
authors: V
authors: Schulz
authors: Jan
authors: J
authors: Proška
authors: Marek
authors: M
authors: Procházka
authors: Karina
authors: K
authors: Weber
authors: Dana
authors: D
authors: Cialla-May
authors: Jürgen
authors: J
authors: Popp