色氨酸荧光猝灭法测定食品中的苏丹红Ⅰ

Determination of Sudan Red Ⅰ in the foodstuff based on the fluorescence quenching effect of tryptophan

在含有十二烷基磺酸钠(SDS)的HAc-NaAc缓冲溶液中,苏丹红Ⅰ的存在对色氨酸的荧光强度有强猝灭作用.实验表明,激发波长为290nm时,色氨酸在360nm处有荧光产生,而苏丹红Ⅰ的存在量与其荧光猝灭程度之间有定量关系.色氨酸的荧光猝灭程度(ΔF)与苏丹红Ⅰ物质的量浓度在1.4×10-6～1.7×10-5 mol.L-1范围内呈线性相关,线性方程为ΔF=4.196 5 C+0.519 1(R2=0.998 9),检出限为2.8×10-7 mol.L-1,加标回收率为92%～98%.

Sudan Red Ⅰ has a strong quenching effect on the fluorescence intensity of tryptophan in a HAc-NaAc buffer solution containing sodium dodecyl sulfate（SDS）.The experiment results indicate that tryptophan has fluorescence at 360 nm with an excitation wavelength of 290 nm.Moreover,the results also show that there is a quantitative relationship between the amount of Sudan Red Ⅰ and the amount of fluorescence quenching（ΔF）.There is a linear relationship between the amount of fluorescence quenching（ΔF） and the amount of Sudan Red Ⅰ when the concentration of Sudan Red Ⅰ is in the range of 1.4×10-6~1.7×10-5 mol·L-1.The equation of the linear relationship is ΔF=4.196 5 C＋0.519 1（R2=0.998 9）,the detection limit is 2.8×10-7 mol·L-1.And the recovery of the added standard sample is 92%~98%.