摘要
在pH8.6的Tris-HCl缓冲溶液中,六偏磷酸钠使天青B在溶液中发生聚集,溶液由天蓝色逐渐变为紫色,体系的吸光度降低,光散射增强。在优化条件下,在6.0×10-7～1.0×10-5mol/L范围内,天青B在602nm处的吸光度降低与六偏磷酸钠浓度呈良好的线性关系,检出限(3σ)为5.3×10-7mol/L。对浓度为5.0×10-6mol/L的六偏磷酸钠溶液平行测定11次,其相对标准偏差为2.5%。本方法用于饮料中添加剂六偏磷酸钠含量的分析,平均标准加入回收率为99.5%～112.3%,可实现六偏磷酸钠的可视化半定量检测。
In a medium of pH 8.6 tris-HCl buffer,azur B gets aggregation in the presence of sodium hexametaphosphate,which results in a color change from sky blue to purple gradually.Under the optimization conditions,the absorbance at 602 nm decreased proportionally to the concentration of sodium hexametaphosphate in the range of 6.0×10-7-1.0×10-5 mol/L.The（3σ） limit of detection was 5.3×10-7 mol/L,and the relative standard deviation was 2.5%（5.0×10-6 mol/L,n=11）.Four kinds of beverages containing additive sodium hexametaphosphate were determined with the recovery of 99.5%-112.3%.In addition,a visual semi-quantificational method of sodium hexametaphosphate could be constructed under white light.
出处
《分析化学》
SCIE
EI
CAS
CSCD
北大核心
2009年第9期1345-1348,共4页
Chinese Journal of Analytical Chemistry
基金
国家自然科学基金(No.90813019)资助项目
关键词
紫外-可见分光光度法
光散射
天青B
六偏磷酸钠
Ultraviolet-visible spectrophotometry
light scattering
azur B
sodium hexametaphosphate
