Study On The Determination Of Basic Orange Ⅱ And Acid Orange Ⅱ In Food By TLC-SERS

Basic orange Ⅱ and Acid orange Ⅱ are a kind of azo dyestuff which are used to dye for textiles, leather products and wood products commonly. These dyes have been shown to be directly pathogenic and moderately toxic in direct contact with humans. and its precursor material, intermediates, degradation products have a certain carcinogenicity. However some unscrupulous traders use them for soy products, egg products and meat products such as food dyeing in recent years for these dyes are easy to color, not easy to leg color, low cost,compared to other water-soluble dyes that can be used for food. Its illegal addition in the food has seriously endangered the health of consumers. Therefore, it is very important to establish a simple, accurate, economical and effective method for the determination of basic orange Ⅱ and acid orange Ⅱ illegally added in food.In this paper, Thin layer chromatography (TLC) and surface-enhanced Raman spectroscopy (SERS) were used to detect basic orange Ⅱ and acid orange Ⅱ. First of all,aqueous silver nano-sol and organic phase of the nano-silver sol were synthesized by the chemical reduction of silver nitrate with water and N, N-dimethylformamide (DMF) as solvents respectively. Then UV-Vis absorption spectra and transmission electron microscopy (TEM) were used to characterize spherical silver nanoparticles. The results show that the nanosilver colloids synthesized in this paper are spherical particles with uniform particles. The nanosilver in aqueous phase and silver nanoparticles in organic phase can. be used as the base of surface enhanced signal of basic orange Ⅱ and acid orange Ⅱ, respectively, and have certain specificity. Second, the conditions of thin layer chromatography were optimized. HSGF254 was selected as the final target for screening.The n-butanol-ethanol-1% aqueous ammonia (10: 1: 2) was identified as the developing agent according to the separation and purification effect.Thirdly, the conditions of Raman spectroscopy, such as coagulant concentration and pH value, silver sol dispense amount and time of action were investigated. Under the optimum conditions,the detection limit of basic orange Ⅱ (S/N= 3) was 1 mg L-1 and the detection limit of acid orange II (S/N=3) was 2.5 mg L-1.In order to verify the practicability of the established method, the yuba, soybean oil and spiced eggs were detected. The experiments were carried out at three concentrations of 3 mg kg-1, 6 mg kg-1 and 10 mg kg-1 for the three blank samples. It proved the practicability of the established detection method, which was verified by HPLC.