罗丹明B光谱探针测定面粉中过氧化苯甲酰

研究在磷酸氢二钠- 磷酸二氢钾缓冲溶液中(pH 6. 84)，以罗丹明B 为光谱探针，分光光度法测定面粉中过氧化苯甲酰(BPO)的方法。结果表明，室温下，罗丹明B-BPO 体系在550nm 波长处有最大吸收，表观摩尔吸光系数(ε)为 1.1 × 104 L/mol·cm。BPO 含量在0.00～0.80mg/ml 范围内符合朗伯比尔定律。检出限为0.056mg/kg，加标回收率为97.5%～101.0% ，RSD 为1.46%～2.53%。该法简便易行，适用于基层单位测定面粉中微量BPO。

Determination of Benzoyl Peroxide in Flour by Spectral Probe of Rhodamine B

A new oxidation system, in Na2HPO4-KH2PO4 buffer (pH 6.84), with rhodamine B as the spectral probe was proposed for determination of benzoyl peroxide (BPO) in flour. Results indicated that this rhodamine B-BPO had an absorption maximum at 550 nm and the apparent molar absorption coefficient was 1.1×104 L/mol·cm. Beer＇s law was obeyed within the concentration of 0.00 to 0.80 mg/ml. The BPO detection limit by this method was 0.056 mg/ kg. The spike recoveries were between 97.5% and 101.0%, and the RSD were between 1.46% and 2.53%. Due to its easy operation and high recovery, this method could be applied directly to analyze trace benzoyl peroxide in flour.