小麦粉中过氧化苯甲酰的定性和定量检测方法研究

Qualitative and Quantitative Detection of Benzoyl Peroxide in Wheat Flour

基于过氧化苯甲酰(BPO)在酸性加热条件下可氧化Fe2+生成Fe3+,Fe3+与二安替比林甲烷(DAPM)形成橙色络合物而显色的原理,建立了小麦粉中BPO快速定性分析的目视比色法和定量分析的分光光度法。研究了缓冲液用量、硫酸亚铁铵用量、DAPM用量、反应温度和反应时间对显色的影响,并对实验条件进行了优化。结果表明,在最优化实验条件下,显色体系的颜色随BPO浓度的升高而加深,色度值呈规律性变化,且在BPO浓度0 mg/L^12 mg/L范围内符合比尔定律,线性回归方程为ΔA=0.036+0.110 C(mg/L),R2=0.9996,420 nm处表观摩尔吸光系数ε=2.765×104 L/(mol·cm)。该法用于实际样品的分析,目视比色法可快速确定BPO的含量范围,分光光度法检出限为0.016 mg/L,加标回收率为97.0~101.8%,相对标准偏差(RSD)小于5%。

Based on the principle that Fe2 ＋ is oxidized to Fe3＋ by benzoyl peroxide （BPO） under acidic and heating conditions, and orange complex was generated by Fe3＋ and diantipyryl methane （DAPM）, visual colorimetry for fast qualitative analysis and spectrophotometric for quantitative analysis of BPO in wheat flour were built. In this paper, the experimental conditions of BPO detection method were optimized, and the experimental influencing factors including buffer solution content, ammonium ferrous sulfate content, DAPM content, reaction temperature and reaction time were studied. The results showed that under the optimum conditions, the color of the complex gradually deepened with the increase of BPO content, and chromatic values changed regularly. It was obeyed Beer＇s taw when the concentration range of BPO was within 0-12 mg/L. The linear regression equation was AA = 0.036 ＋ 0.1 l0 C （rag/L） with correlation coefficient of 0.9996, and the apparent molar absorption coefficient was 2.765 x 104 L/（mol＇cm）at 420 nm. The recovery rate for spiked standards was 97.0--101.8%, with the relative standard deviation （RSD） less than 5%. The BPO content range was rapidly determined by visual colorimetry, and its detection limit was 0.016 mg/L.