카드뮴과 구리의 불꽃원자흡광분석을 위한 전처리방법으로써 습식 및 건식 회화의 비교

Analytical comparison between wet ashing digestion and dry ashing digestion for cadmium and copper by flame atomic absorption apectrophotometry (F-AAS)

In the present study, to adopt the more precise and simpler method for preparation of biological samples, the digestion methods were evaluated by comparing between the recovery rates of cadmium (Cd) and copper (Cu). Three groups of sample were prepared as followings; group 1 - standard solution only of Cd (0.05, 0.1, 0.5, 1, 2 ppm) and Cu (0.1, 0.5, 1, 3, 5, 10 ppm) were digested by wet- and dry-ashing digestion, group 2 - the rat liver samples spiked with Cd 0.4 ㎍ and Cu 30 ㎍ were digested by wet- and dry-ashing digestion, and group 3 - the rat liver samples spiked with concentrations of Cd and Cu of standard solution only were digested by dry-ashing digestion alone. Additionally, to verify the methods used in this study, NIST(SRM: NIST bovine Liver 1577b) samples digested by wet- and dry-ashing digestion were also prepared. All digested samples were determined with F-AAS under same analytical condition. The average recoveries of Cd of group 1 were 102.7% in the wet digested samples and 57.0% in the dry digested ones, and those of Cu of group 1 were 98.8% in the wet digested samples and 42.1% in the dry digestion. The recoveries of Cd of group 2 were 97.0% in the wet digested samples and 71.4% in the dry digestion. The average recoveries of group 3 which were 97.0% for Cd and 76.5% for Cu were in the similar ranges with the results of dry digested samples of group 2,. Furthermore, the values of NIST samples fell down in the ranges of certified values. Conclusively, the results of this study indicated that for precise and simple preparation for Cd and Cu detection the wet-ashing digestion method may be more reliable than dry-ashing one. Therefore, wet-ashing digestion method can be suggested as a more suitable method for sample preparation for Cd and Cu in various biological samples.