title: Determination of Sudan IV in hot chilli powder with luminol/dissolved oxygen chemiluminescence system.
abstract: BACKGROUND
  A green, simple and sensitive flow injection chemiluminescence (CL) procedure is proposed for the determination of Sudan dyes. The method is based on the finding that Sudan I, II, III and IV markedly enhance the CL intensity of the luminol/dissolved oxygen reaction.
  
  
  RESULTS
  The increment in CL intensity was proportional to the concentration of Sudan I, II, III and IV, giving calibration graphs linear over the ranges 0.007-1, 0.5-30, 1-10 and 0.7-300 ng mL(-1) respectively (R(2) >or= 0.9981), with limits of detection of 0.002, 0.2, 0.3 and 0.2 ng mL(-1) respectively. At a flow rate of 2 mL min(-1), complete determination of Sudan dyes, including sampling and washing, could be accomplished in 40 s, with relative standard deviations of less than 5% (n = 7).
  
  
  CONCLUSIONS
  The proposed method was successfully applied to the determination of Sudan IV in contaminated hot chilli powder, with recoveries ranging from 89.3 to 108.4%. The possible mechanism of enhancement of the luminol/dissolved oxygen CL reaction by Sudan IV can be attributed to the acceleration of electron transfer. Compared with other procedures, the proposed CL method offers the highest sensitivity and the least reagent consumption for the determination of Sudan IV.
authors.affiliation: Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi'an, 710069, China.
authors.forename: Lichuan
authors.initials: L
authors.lastname: Niu
authors.forename: Zhenghua
authors.initials: Z
authors.lastname: Song
authors.forename: Donghua
authors.initials: D
authors.lastname: Chen
mesh_terms: D001391:Azo Compounds / Q000032:analysis*; D002212:Capsicum; D005504:Food Analysis / Q000379:methods*; D005506:Food Contamination; D057230:Limit of Detection; D008163:Luminescent Measurements / Q000379:methods*; D008165:Luminol; D010100:Oxygen / Q000032:analysis*; D028321:Plant Preparations; D011208:Powders; D012995:Solubility; D017365:Spices / Q000032:analysis*
chemical_list: D001391:Azo Compounds; D028321:Plant Preparations; D011208:Powders; D008165:Luminol; C009213:Scarlet Red; D010100:Oxygen