Quantitative Dfetermination of Coumarin in Food by Surface-enhanced Raman Spectroscopy

A method was established for the determination of coumarin in various foods by surface. enhanced Raman spectroscopy in a hydrochloric acid. potassium chloride solution (pH = 5. 0) with 55 nm Au nanoparticles as Raman substrate. Under the optimal experiment conditions such as concentrated gold sol with concentration multiple of 50, 5 s of laser irradiation time and 1: 1 mixing ratio of gold sol and solution, the method was used for the direct determination of coumarin. The method had a good linearity between the peak intensity and the courmain concentration in the range of 1. 00 - 100. 0 mg/L, and the detection limit was 0. 91 mg/L. For the determination of real samples of courmain in vegetables, fruits, sweets and pastries, 10 g of sample was added in 50 mL of hydrochloric acid. potassium chloride solution in a beaker, and then ultrasonically extracted for 0. 5 h. After transferred into a 100-mL flask, the sample solution was filtered and 10 mL of supernatant was taken and diluted to 100 mL for the further analysis. The concentration of courmain was determined to be 0. 61-5. 52 g/kg. The relative standard deviations were 0. 6% - 14. 0%. The spiked recoveries of these samples ranged from 75. 1% to 103. 2%. This method is simple, and has wide linear range and high accuracy.