[Objective] The purpose was to discuss the optimum condition for determining the selenium content in tea by microwave digestion and molecule fluorescence photometry. [Method] The tea sample was digested by microwave digestion. The 4,5-benzo piaselenol with the strong fluorescence characteristic was prepared by reaction between the selenium (IV) in the tea and DAN (2,3-diaminonaphthalene) under acidic condition, and then the selenium content in the tea was detected by molecule fluorescence photometry and the microwave digestion condition was optimized. [Result] The condition for digesting the tea sample by microwave chemical reactor was follows: 5.0% sulfate at 5.0 ml was added into the sample for wetting and HNO3∶HClO4 (4∶1) 10.0 ml was added into it for digesting at 0.20 kW for 30 min. The optimum detecting contion was follows: pH of 1.5-2.0, dosage of EDTA-hydroxylamine hydrochloride mixed solution being 0.0 ml, dosage of 0.1% DAN being 5.0 ml, heating by the boiled water for 5 min, extracting by 6.0 ml cyclohexane and detecting the fluorescence intension under the excitation wavelength of 377 nm and the emission wavelength of 519 nm. There was a good linear relation with fluorescence intension when the selenium content was 1.0-7.0 μg, with R2 of 0.991 6 and the relative standard deviation (RSD) was 2.5%. [Conclusion] In comparison with the determination by the wetting digestion, the determination results of microwave digestion was reliable, simple and quick.%[目的] 探讨微波消解分子荧光法测定茶叶中硒含量的最佳条件.[方法] 采用微波消解法消解茶叶样品,利用茶叶中的硒(IV)与DAN (2,3-二氨基萘)在酸性条件下反应生成具有强荧光特性的4,5-苯并苤硒脑,用荧光光度法测定茶叶中硒含量,优化微波法消解条件.[结果] 采用微波化学反应器消解茶叶样品的条件为:0.5 g样品加5.0 ml 5.0%硫酸润湿,加入HNO3∶HClO4(4∶1)10.0 ml,在0.20 kW时消解30 min.最佳测定条件为:pH 值1.5~2.0,EDTA-盐酸羟胺混合液用量20.0 ml,0.1% DAN加入量5.0 ml,沸水浴加热5 min,6.0 ml环己烷萃取,于激发波长377 nm、发射波长519 nm条件下测定荧光强度.该方法在硒含量1.0~7.0 μg时,与荧光强度呈良好的线性关系,R2值为0.990 9,RSD值为2.5%.[结论] 与湿法消解法相比,微波消解方法测定结果可靠,简单快捷.
展开▼
机译：微波消解-火焰原子吸收光谱法测定黔产果上叶中5种金属元素的含量Determination of Five Metallic Elements in Guoshangye from Guizhou by Microwave Digestion-flame Atomic Absorption Spectrometry
