title: Utility of 4-chloro-7-nitrobenzofurazan for the spectrofluorimetric determination of butylated hydroxyanisole and propyl gallate in foodstuffs.
abstract: A spectrofluorimetric method is presented for the determination of 2 synthetic phenolic antioxidants (SPAs), butylated hydroxyanisole (BHA), and propyl gallate (PG) in foodstuffs. The proposed method is based on the derivatization of SPAs with 4-chloro-7-nitrobenzofurazan (NBD-Cl) in phosphate buffer of pH 9.0 to yield a highly fluorescent brown product. The optimum experimental conditions have been studied carefully. Linear calibration curves were obtained over the concentration range of 0.20 to 40 μg mL⁻¹ for BHA, and 0.80 to 50 μg mL⁻¹ for PG, using NBD-Cl reagent. The detection limits were 18 ng mL⁻¹ for BHA, 55 ng mL⁻¹ for PG. Intra-day and inter-day relative standard deviations at 3 different concentrations were determined. The high recovery values indicate the accuracy of the proposed methods, and low relative standard deviation values indicate good precision. The results presented in this report show that the applied spectrofluorimetric method is acceptable for the determination of the 2 SPAs in the foodstuffs. Other SPAs, tertiary butyl hydroquinone and butylated hydroxytoluene in foodstuffs do not interfere with the proposed method.
  
  
  CONCLUSIONS
  In this spectrofluorimetric method, NBD-Cl as a derivation agent is used to detect synthetic phenolic antioxidants. The method specificity has been greatly improved; there was no interference from other commonly used phenolic substances.
authors.affiliation: Faculty of Life Science and Technology, Kunming University of Science and Technology, Yunnan Province, China.
authors.forename: Miao
authors.initials: M
authors.lastname: Chen
authors.forename: Zhigang
authors.initials: Z
authors.lastname: Tai
authors.forename: Xujia
authors.initials: X
authors.lastname: Hu
authors.forename: Mousheng
authors.initials: M
authors.lastname: Liu
authors.forename: Yaling
authors.initials: Y
authors.lastname: Yang
mesh_terms: D009327:4-Chloro-7-nitrobenzofurazan / Q000737:chemistry*; D000975:Antioxidants / Q000032:analysis*; D002083:Butylated Hydroxyanisole / Q000032:analysis*; D002138:Calibration; D005456:Fluorescent Dyes / Q000737:chemistry*; D005503:Food Additives / Q000032:analysis*; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D057230:Limit of Detection; D010938:Plant Oils / Q000737:chemistry*; D011435:Propyl Gallate / Q000032:analysis*; D011786:Quality Control; D015203:Reproducibility of Results; D012997:Solvents / Q000737:chemistry; D013050:Spectrometry, Fluorescence; D013997:Time Factors
chemical_list: D000975:Antioxidants; D005456:Fluorescent Dyes; D005503:Food Additives; D010938:Plant Oils; D012997:Solvents; D002083:Butylated Hydroxyanisole; D011435:Propyl Gallate; D009327:4-Chloro-7-nitrobenzofurazan