摘要
在六次甲基四胺-氢氧化钠缓冲溶液中,以二甲酚橙为显色剂,邻菲啰啉为掩蔽剂,建立了分光光度法测定茶叶中铅含量的方法。结果表明,二甲酚橙与铅反应生成红色络合物,其最大吸收波长为575 nm,铅含量在0~8 mg/L范围内符合朗伯-比尔定律,摩尔吸光系数为2.05×104L/(mol·cm)。用本法测定了茶叶中的铅,得到加标回收率在97.5%~102.0%之间,相对标准偏差小于1.32%,结果符合分析要求。本法简单可靠、准确灵敏,适用于茶叶中铅含量的测定。
A spectrophotometric method for the determination of lead content in tea was developed by using methenamine-sodium hydroxide as buffer solution,xylenol orange as color reagent,phenanthroline as masking agent. The results showed that lead could form red complex with xylenol orange,the maximum absorption of the complex occurred at 575 nm. The lead content was obeyed Lambert Beer law in the range of 0 ~ 8 mg/L,the molar absorptivity was 2. 05 × 104 L/(mol·cm). Values of recovery were found in the range of 97. 5% ~ 102. 0%,and values of RSD were less than 1. 32%. The results were accorded with requirements of analysis. The method was simple,reliable,accurate and sensitive,and it was suitable for detecting lead content in tea.
出处
《应用化工》
CAS
CSCD
北大核心
2017年第3期601-603,606,共4页
Applied Chemical Industry
基金
四川省教育厅重点项目(13ZA0123)
关键词
二甲酚橙
分光光度法
茶叶
铅
xylenol orange
spectrophotometry
tea
lead
