title: Rapid determination of nitrite in foods in acidic conditions by high-performance liquid chromatography with fluorescence detection.
abstract: In this study, a simple, rapid, and sensitive method for the determination of nitrite (NO2 (-) ) in food samples by high-performance liquid chromatography with fluorescence detection in acidic conditions had been developed. The derivatization of the nitrite with 2,3-diaminonaphthalene was performed in acidic conditions to yield the highly fluorescent 2,3-naphthotriazole, which was directly analyzed by high-performance liquid chromatography with fluorescence detection without adjusting the solution to alkaline. The analysis column was reversed-phase C8 column. A constant flow rate of 1.0 mL/min was employed using water/acetonitrile as the mobile phase in isocratic mode (70:30, v/v). Fluorescence was monitored with excitation at 375 nm and emission at 415 nm. The standard calibration curves were linear for nitrite in different matrixes in the concentration range of 0-100 μg/L, and the correlation coefficients ranged from 0.9978 to 0.9998. The limits of detection and quantification were in the ranges of 0.012-0.060 and 0.040-0.20 mg/kg, respectively. The recoveries of nitrite from samples spiked at three different concentrations were 74.0-113.2%, and the relative standard deviations of the recovery results (n = 6) were 1.67-10.8%. The proposed method has good repeatability and is very sensitive and simple. It has been successfully used to determine nitrite in foods.
authors.affiliation: Hangzhou Center for Disease Control and Prevention, Hangzhou, P. R. China.
authors.forename: Xiao-Fang
authors.initials: XF
authors.lastname: Wang
authors.affiliation: Hangzhou Center for Disease Control and Prevention, Hangzhou, P. R. China.
authors.forename: Ji-Cai
authors.initials: JC
authors.lastname: Fan
authors.affiliation: Hangzhou Center for Disease Control and Prevention, Hangzhou, P. R. China.
authors.forename: Ren
authors.initials: R
authors.lastname: Ren
authors.affiliation: Hangzhou Center for Disease Control and Prevention, Hangzhou, P. R. China.
authors.forename: Quan
authors.initials: Q
authors.lastname: Jin
authors.affiliation: Hangzhou Center for Disease Control and Prevention, Hangzhou, P. R. China.
authors.forename: Jing
authors.initials: J
authors.lastname: Wang
mesh_terms: D002851:Chromatography, High Pressure Liquid; D005433:Flour / Q000032:analysis*; D005453:Fluorescence; D005504:Food Analysis; D006863:Hydrogen-Ion Concentration; D009573:Nitrites / Q000032:analysis*; D012275:Oryza / Q000737:chemistry*; D014230:Triazoles / Q000032:analysis* / Q000138:chemical synthesis
chemical_list: D009573:Nitrites; D014230:Triazoles
keywords: 2,3-Naphthotriazole; Fluorescence detection; High-performance liquid chromatography; Nitrite