L-苯丙氨酸荧光猝灭法测定果蔬中激动素和6-苄基腺嘌呤

Determination of kinetin and 6-benzylaminopurine in fruits and vegetables based on L-Phe fluorescence quenching

为了监测果蔬中植物激素的污染状况，本研究首先利用荧光偏振信号法计算荧光偏振度和荧光各向异性度来区分激动素和6-苄基腺嘌呤2种细胞分裂素，然后建立了同时测定果蔬中激动素和6-卞基腺嘌呤残留量的L-苯丙氨酸荧光猝灭法。结果显示：L-苯丙氨酸-激动素体系对应着较大的荧光各向异性度（荧光偏振度），而L-苯丙氨酸-6-苄基腺嘌呤体系则对应着较小的荧光各向异性度（荧光偏振度）。激动素和6-苄基腺嘌呤的回收率均为95.00%~104.00%，相对标准偏差为2.22%~4.13%。结果表明该方法可用于市售果蔬李子和番茄样品表皮中激动素和6-苄基腺嘌呤的测定。

To monitor the pollution of plant hormones in frutis and vegetables, the degree of fluorescence polarization and the degree of fluorescence anisotropy were employed based on the measurements of the polarized fluorescence signals to distinguish two natural exogenous cytokinins of kinetin （ KT） and 6-benzylaminourine firstly. Then a method of simultaneous determination of KT and 6-benzylaminourine was established by L-Phe fluorescence quenching. L-Phe-KT system exhibited a large degree of fluorescence anisotropy （ fluorescence polarization） , while the L-Phe-6-BA system showed a small degree. The recoveries of KT and 6-BA were both 95. 00%-104. 00%,with the relative standard deviation（RSD） of 2. 22%-4. 13%. The method is applicable to simultaneous determination of kinetin and 6-benzylaminourine in plum skin and tomato skin.