Abstract: A new ionic liquid sensitized sepctrophotometic method was developed on the basis of the Al(Ⅲ)-chromeazurol S (CAS)-1-n-tetradecyl-3-methylimidazolium (C14minBr) system. In the presence of Britton-Robinson buffer solution at pH 4.8, the color reaction of Al(Ⅲ) with chromeazurol S (CAS) could be sensitized by the addition of ionic liquid, C14minBr. The maximum absorption wavelength of the stationary ternary complex Al(Ⅲ)-CAS-C14minBr was 621 nm and the apparent molar absorption coefficient of the complex was 1.942 × 105 L/(mol?cm). Beer’s law was obeyed for Al(Ⅲ) in the range of 0.001–0.150 μg/mL. The developed method was used for the determination of vermicelli and could result in the consistent results from flame atomic absorption spectrophotometry. The recovery rates in the spiked samples were in the range of 97.8%–101.8%.

Key words: 1. School of Chemical Engineering, Huaihai Institute of Technology, Lianyungang 222005, China, 2. Department of Chemistry, Yangzhou University, Yangzhou 225002, China