Kehoe D F, Sullivan D M, Smith R L
Hazleton Laboratories America, Inc., Madison, WI 53707.
J Assoc Off Anal Chem. 1988 Nov-Dec;71(6):1153-5.
Historically, compounds that contain gold have been used to treat conditions such as rheumatoid arthritis in humans. However, understanding of the metabolic fate of gold in biological tissues has been limited by lack of sensitive quantitative methods of analysis. We addressed this problem by developing a graphite furnace atomic absorption (GFAA) spectrophotometric method to measure trace amounts of gold. This method was validated on small samples of beef liver, kidney, and bone. The samples were digested in micro-Kjeldahl flasks with a mixture of sulfuric, perchloric, and nitric acids; the residue was treated with aqua regia and extracted into methylisobutyl ketone (MIBK); levels of gold were then measured by GFAA. All the reagents were of an ultra-pure grade and were monitored for gold content. We established that the linear range of quantitation was from 1 to 2500 ppb. Multiple extractions with MIBK were not necessary to recover all the gold, and, in most cases, use of ultra-pure acids was not necessary. A scan of the extracts by inductively coupled argon plasma atomic emission spectrophotometry revealed no appreciable concentration of elements that would be most likely to interfere with the determination of gold. Average recoveries of gold ranged from 102 to 111%, and the overall coefficient of variation was 5.5%.
从历史上看，含金化合物已被用于治疗人类的类风湿性关节炎等病症。然而，由于缺乏灵敏的定量分析方法，对生物组织中金的代谢命运的了解一直有限。我们通过开发一种石墨炉原子吸收（GFAA）分光光度法来测量痕量金，解决了这个问题。该方法在牛肝、肾和骨的小样本上得到了验证。将样本在微量凯氏烧瓶中用硫酸、高氯酸和硝酸的混合物进行消化；残渣用王水进行处理，然后萃取到甲基异丁基酮（MIBK）中；然后通过GFAA测量金的含量。所有试剂均为超纯级，并对其金含量进行监测。我们确定定量的线性范围为1至2500 ppb。用MIBK进行多次萃取并非回收所有金所必需，而且在大多数情况下，也无需使用超纯酸。通过电感耦合氩等离子体原子发射分光光度法对萃取物进行扫描，结果表明没有明显浓度的可能最易干扰金测定的元素。金的平均回收率在102%至111%之间，总体变异系数为5.5%。
