勞工血液中鎘生物偵測分析方法之研究

Biological Monitoring Analytical Method of Blood for Cadmium in Workers

鎘在工業上的應用相當廣泛，勞工若長期暴露在鎘的工作環境中可能引起身體的病變，因此為保障勞工健康，對於鎘作業人員執行例行性的生物偵測，可作為勞工健康危害的早期偵測指標。由於生物檢體中的鎘濃度極低（約在ng/g程度），基質又相當複雜，所以極易發生分析上的困難，石墨爐原子吸收光譜法因具有高靈敏度（≦ ng/g），適合少量樣品（≦ 100 μL ）分析，及可藉由石墨爐溫度程式的控制，有效降低基質干擾效應等特性，因此極適合作為生物檢體中微量元素的分析之用。本研究利用石墨爐原子吸收光譜法技術探討血液樣品中鎘直測的分析可行性，首先建立儀器操作的最適化條件，次就血液樣品基質的干擾效應進行探討。實驗的結果顯示，血液中存在的有機及無機基質成份均將對鎘的測定造成影響。本研究對於有機基質的干擾係利用在灰化階段通氧的技術予以去除；另對於無機基質成份，特別是氯化鹽類對鎘測定所造成的干擾，則分別利用NH4H2P04與Pd-NH4N03為基質修飾劑予以克服。本研究在儀器最適化條件的操作下，配合基質修飾劑的使用，已可直接以水溶液製作校正曲線來進行血液樣品中鎘的直測分析。為確認此直測方法的可行性，本研究並以標準參考樣品進行驗證，所測得Seronorm 20502全血標準樣品之鎘分析值為0.89± 0.06 ppb，而確認值為0.9 ppb，故所得的分析值與確認值為一致，證明本研究所建立的方法在實際應用上應具有極高的可行性。

Cadmium is widely used in industry. However, long term exposure to Cd workers may induce pathophysiological changes. The biological monitoring of Cd is therefore of importance and can be used as an index of early health risk. The analysis of Cd is difficult because its concentration of body fluids is extremely low (ng/g level) and the matrix is very complicated. The graphite furnace atomic absorption spectroscopy (GFAAS) is especially useful in determining the trace elements in biological samples because of its properties of high sensitivity (ng/g), low sample volumes (≦100 μL), and low matrix effects through controlling the temperature program of graphite furnance. In this study, we therefore attempted to measure the Cd in blood samples directly. The optimal parameters of the GFAAS and the matrix effects of blood analysis were investigated. The results showed that both organic and inorganic compounds in blood may induce high background and interfere with the trace analysis of Cd. In this study, the technique of ashing with oxygen was used to remove the interference of organic compounds. Simultaneously, matrix modifiers of NH4H2P04 and Pd-NH4N03 were used to remove the interference of inorganic chlorides. The results therefore indicate that the matrix effect is almost completely removed by optimal instrumental analysis and use of matrix modifiers. From the determination of the Seronorm 205052, value of 0.89±0.06 ppb was obtained, and concur with the certified values of 0.9 ppb of Cd. The method used to detect the Cd concentration of samples was therefore established.