浊点萃取-石英双缝管捕集火焰原子吸收光谱法分析铬价态  

Speciation Determination of Chromium Using Cloud Point Extraction with Double-slotted Quartz Tube Atom Trap-Flame Atomic Absorption Spectrometry

作　　者：卢菊生[1] 田久英[1] 吴宏[1] 

机构地区：[1]徐州师范大学化学化工学院,徐州221116

出　　处：《分析化学》2009年第1期99-102,共4页Chinese Journal of Analytical Chemistry

基　　金：江苏省高校自然科学基金(No.07KJB150112);徐州师范大学自然科学基金(No.07XLB10)资助项目

摘　　要：在不同pH值的缓冲溶液中,亚硝基苯胲铵盐(铜铁试剂)可与Cr(Ⅵ)及Cr(Ⅲ)络合生成中性疏水络合物,以Triton X-114为萃取剂,浊点萃取分离富集Cr(Ⅵ)及总铬,石英双缝管原子捕集-火焰原子吸收光谱法(STAT-FAAS)测定铬价态。实验对浊点萃取时溶液的pH值、铜铁试剂和Triton X-114的用量、离心分离时间、平衡温度和时间等影响因素进行了研究。结果表明,分别在pH=3.0和6.0的溶液中,40℃恒温加热15min后,离心5min,Triton X-114浊点萃取Cr(Ⅵ)及总铬的富集倍数达到50倍(100mL起初样品溶液/2mL最终测定液)。和普通火焰原子吸收光谱法(FAAS)相比,利用石英双缝管原子捕集技术,STAT-FAAS法测定铬的灵敏度提高了近5倍。本方法测定Cr(Ⅵ)及总铬的线性范围分别为0.005～0.5mg/L和0.01～1.2mg/L;检出限分别为0.66μg/L和0.81μg/L。Cloud point extraction （CPE） for speciation determination of chromium in environmental water samples with double-slotted quartz tube atom trap-flame atomic absorption spectrometry（STAT-FAAS） was developed. Preconcentration of chromium（ VI ） and total chromium in different pH solutions was achieved by CPE, with nitrosophenyl hydroxylamine （cupferron） as the chelating agent and Triton X-114 as the cloud point extractant. The effect of pH, concentration of cupferron, Triton X-114, centrifugalization time, equilibration temperature and time on CPE were studied. The results showed that the enrichment factor was 50 for chromium（ VI ） or total chromium from the initial 100 mL sample solution to the final 2 mL determined solution, when the system solution buffered at pH 3.0 or 6.0, was kept in the thermostatic bath maintained at 40 ℃ for 15 min, then centrifuged for 5 min. Compared with the FAAS method, the sensitivity was improved 5-fold for chromium by STAT-FAAS method. The linear concentration range was 0. 005 - 0.5 mg/L for chromium（VI） and 0. 01 - 1.2 mg/L for total chromium. The detection limits of chromium（VI） and total chromium were 0. 66 μg/L and 0. 81 μg/L, respectively.

关 键 词：铬 形态分析 铜铁试剂 浊点萃取 石英双缝管原子捕集-火焰原子吸收光谱法 

分 类 号：O657.31[理学—分析化学] X132-1[理学—化学]