title: A new potassium tetrabromoaurate (III)-luminol chemiluminescence system for the determination of folic acid in milk powder.
abstract: A new chemiluminescence (CL) system based on the CL-emitting reaction between potassium tetrabromoaurate (III) [Au(III)] and luminol in alkaline medium is described in this paper. On the basis of this study, folic acid (FA) could dramatically enhance CL intensities, and incorporated with flow injection (FI) and solid-phase extraction (SPE), the novel CL system has been applied for the determination of FA in infant formula milk powder. Under optimum conditions, the CL intensities were linearly related to the concentration of FA in the range of 8.0 × 10⁻⁸ to 4.0 × 10⁻⁵ g/L with a correlation coefficient of 0.999, and the detection limit was 2.0 × 10⁻⁸ g/L. The relative standard deviation was 3.5% for 1.0 × 10⁻⁶ g/L FA. The optimal conditions for the detection of FA were evaluated, and the interferences from some common inorganic ions and a couple of relevant organic compounds were also investigated.
  
  
  CONCLUSIONS
  The new Au(III)-luminol chemiluminescent system is proposed for the determination of FA; it will be an adequate technique for the analysis of low FA concentrations in pharmaceutical preparations and food samples, and it will have potential analytical applications for other substances.
authors.affiliation: College of Biology Science and Engineering, Hebei University of Economics and Business, Shijiazhuang, China. zhaoshihao_11@yahoo.cn
authors.forename: Shihao
authors.initials: S
authors.lastname: Zhao
authors.forename: Pingping
authors.initials: P
authors.lastname: Zhang
authors.forename: Xiaohui
authors.initials: X
authors.lastname: Liang
authors.forename: Dongliang
authors.initials: D
authors.lastname: Hua
authors.forename: Tongsuo
authors.initials: T
authors.lastname: Ma
authors.forename: Guanglu
authors.initials: G
authors.lastname: Pei
mesh_terms: D001965:Bromides / Q000737:chemistry*; D002138:Calibration; D017022:Flow Injection Analysis; D005492:Folic Acid / Q000032:analysis*; D017612:Gold Compounds / Q000737:chemistry*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007202:Indicators and Reagents / Q000737:chemistry*; D007223:Infant; D041943:Infant Formula / Q000737:chemistry*; D007700:Kinetics; D057230:Limit of Detection; D049408:Luminescent Agents / Q000737:chemistry*; D008163:Luminescent Measurements; D008165:Luminol / Q000737:chemistry*; D008894:Milk Proteins / Q000737:chemistry*; D009994:Osmolar Concentration; D010084:Oxidation-Reduction; D015203:Reproducibility of Results; D052616:Solid Phase Extraction
chemical_list: D001965:Bromides; D017612:Gold Compounds; D007202:Indicators and Reagents; D049408:Luminescent Agents; D008894:Milk Proteins; D008165:Luminol; D005492:Folic Acid; C037129:gold tetrabromide, acid