锌-甲基百里香酚蓝显色反应测定微量锌的研究

Determination of Trace Zinc by Zinc-Methyl Thymol Blue Chromogenic Reaction

研究了在曲拉通-100(Triton X-100)存在下,醋酸-醋酸钠缓冲溶液中,甲基百里香酚蓝与锌(Ⅱ)形成朱砂红色配合物,据此建立了分光光度法测定锌含量的方法。实验表明,当配合物最大吸收波长为520 nm时,锌含量在0~1.5 mg/L范围内符合比耳定律,表观摩尔吸光系数4.1×104L·mo L-1·cm-1。用于大米中微量锌的测定,相对标准偏差(RSD,n=6)为1.3%~2.4%,加标回收率在96%~104%之间。

Studied in Triton X-100,in the presence of Acetic acid-sodium acetate buffer in the buffer solution,methyl phenol blue thyme and zinc complexes( Ⅱ) form the cinnabar red,on the basis of established a spectrophotometric method of determination of zinc content. Experiments show that when the maximum absorption wavelength of the complex is 520 nm,the zinc content within the range of 0 ~ 1. 5 mg/L conforms to beale’s law,and the apparent molar absorption coefficient is 4. 1 × 104 L·mol-1·cm-1. Used for the determination of trace zinc in rice,the relative standard deviation( RSD,n = 6) is 1. 3% ~ 2. 4%,and the standard recovery rate is between 96% ~ 104%.