Determination of synthetic food colourant in tea drink by absorptionspectrophotometry
*Corresponding authorÂ
College of Science, Nanjing University of Aeronautics and Astronautics, Nanjing, 210016, China
Abstract
In this paper, two kinds of simple, precise and sensitive approaches are developed for the determination of synthetic food colourant in the tea drink based on absorption spectrophotometry. One method focuses on the analysis of the intensity at 480nm wavelength of original absorption spectra. The other one aims at the technology of calculating the intensity at 462nm and 524nm wavelength of the first derivative of ratio spectra. In addition, both of correlation coefficients are found to be near to 0.999. Validated by assessing the precision, limit of quantification, limit of detection and sensitivity, both of them show accurate, simple, cheap and less time-consuming feature. Therefore, they can be suitably applied in the estimation of the synthetic food colourant in tea drink.
INTRODUCTION
Tea drink is one of the most popular drinks in the world. China, the birthplace of tea, exports a great quantity of tea leaves to various countries in the world. Owing to tea has anticarcinogenic action (1-3) and resists radiation damage (4, 5). Tea has become the favourite for more and more people. So safety detection of tea, such as identification of tea adulterations, analysis of pesticide residues and determination of microbial, fluroine and heavy metal contamination, becomes important nowadays.
Food colourant addition is one of the problem in tea adulterations. Some synthetic colourants may be pathogenic, especially if they are consumed in excess. Therefore, safety data for every synthetic colourant food additive have been repeatedly determined and evaluated by the Food and Agricultural Organization and World Health Organization. The use of synthetic colourants as food additives is common in most countries. Different methods have been employed for the determination of colourants in diverse matrices, including chromatographic methods, such as column chromatography, HPLC and TLC (6-9).Numerous procedures are based on the use of el ...
