高锰酸钾—鲁米诺化学发光体系测定香草醛

为了拓展流动注射化学发光法在食品检测中的应用,利用草醛能够增敏NaOH介质中高锰酸钾—鲁米诺化学发光体系的发光信号的特点,建立了化学发光测定香草醛的方法。文中考察了介质浓度、发光试剂浓度等因素对发光体系信号的影响,确定了测定香草醛的最佳条件:介质NaOH浓度为0.20 mol/L,高锰酸钾浓度为3.0×10-5mol/L,鲁米诺浓度为7.0×10-5mol/L。在优化实验条件下,体系的发光强度与香草醛浓度在5.0×10-8～3.0×10-6 g/mL内呈线性关系,标准曲线:ΔI=7.188 3×108C(g/mL)+71.767 4(r=0.994 2)。对5.0×10-7g/mL的香草醛平行测定11次,相对偏差为1.3%,其检出限为1.1×10-8g/mL。建立了测定香草醛的流动注射化学发光法新方法,并成功地测定了片剂中香草醛的含量,回收率为98%～104%。

Determination of vanillin with potassium permanganate-luminol chemiluminescence system

Based on the fact that the chemiluminescence(CL) reaction of potassium permanganate and luminol in alkaline medium could be enhanced by vanillin,a new analytical method of chemiluminescence to detect vanillin was developed,which expands the application of flow-injection chemiluminescence in food analysis.The effect of type of medium and concentration of reagents on CL intensity was investigated.The results showed that the optimum concentrations of NaOH,KMnO4 and Lumino were 0.20 mol/L,3.0 × 10-5 mol/L and 7.0 × 10-5 mol/L,respectively.Under the optimum conditions,linearity relationship of values of CL intensity and mass concentration of vanillin was obtained in the range of 5.0 × 10-8~3.0 × 10-6 g/mL,with a equation of linear regression as ΔI = 7.188 3 × 108 C(g/mL) + 71.767 4(r = 0.994 2).Parallel determination of 5.0×10-7 g/mL vanillin for 11 times show that the RSD is 1.3% with a detection limit of 1.1×10-8 g/mL.A new method of flow-injection chemiluminescence to detect vanillin was found,which has been successfully applied to the determination of vanillin in pill and the recovery rate obtained were in the range of 98%~104%.