利用聚四氟乙烯为化学改进剂降低电热原子吸收测定铬的基体干扰  

Application of PTFE Modifier for the Removal of Matrix Interferences with Chromium in Electrothermal Atomic Absorption Spectrometry

作　　者：汪福意[1] 江祖成[1] 

机构地区：[1]武汉大学化学学院

出　　处：《分析科学学报》1999年第2期111-114,共4页Journal of Analytical Science

摘　　要：本文研究了电热原子吸收光谱测定痕量铬时几种常见金属离子的干扰作用。结果表明，除Ｋ，Ｎａ外，Ｃａ，Ｃｕ，Ｓｒ和Ｂａ的氯化物对铬的测定产生严重的负干扰；当采用聚四氟乙烯（ＰＴＦＥ）悬浮液为化学改进剂时，上述干扰离子的干扰都得到有效的抑制或消除。本法已应用于ＮＩＳＴ１５７３生物标准样品（蕃茄叶），鲜牛奶和纯氯化铜试剂中痕量铬的直接分析，结果满意。The interferences of matrix components(in chlorides) with chromium absorption in electrothermal atomic absorption spectrometry(ETAAS) were investigated. The suppression effect of polytetrafluoroethylene(PTFE) slurry on the interferences and its mechanism were subsequently described. Except for K and Na, the other tested components (Ca, Cu, Ba and Sr) seriously supressed chromium absorption in the absence of PTFE. However,in the presence of PTFE modifier, the interfernces of 104 excess of matrices could be removed or reduced significantly. The proposed method was successfully applied to determine trace chromium in NIST1573 reference material(tomato leaf), copper chloride and fresh milk with no chemical pretreatment. The determined value of Cr in reference material was in good agreement with the certified value. The recoveries of chromium in real samples were 97.0 and 104.2%, respectively.

关 键 词：ETAAS 铬 基体干扰 聚四氟乙烯 化学改进剂 测定 

分 类 号：O614.611[理学—无机化学]