| Summary: | 碩士 === 高雄醫學大學 === 醫學研究所碩士班 === 93 === Preconcentration techniques play important roles in on-line methods development. In the present study, using a polytetrafluoroethylene (PTFE) tubing preconcentration and flow-injection flame atomic absorption spectrometric detection, we have successfully developed an analytical system for enrichment and determination of trace lead (Pb) and copper (Cu) in urine. The sample mixed with ammonium pyrrolidine dithiocarbamate (APDC) was passing through a PTFE tubing and the Pb (Ⅱ)-PDC and Cu (Ⅱ)-PDC complex were absorbed quantitatively on the tubing. The preconcentrated complex was effectively eluted by hydrochloric acid solution and introduced into the nebulizer-burner system. In this method, 0.2% (v/v) HNO3 solution was used as carrier solution and the optimal flow rate of nebulizer was set at 6.0 mL/min. The calibration curve was linear over the concentration range of 0.1-0.6 mg/L and 0.05-0.4 mg/L for Pb and Cu, respectively. The limits of detection were 25 and 4 mg/L, for lead and copper, respectively. The intra- and inter-assay for lead and copper at three levels of standard solution (0.1, 0.2 and 0.3 mg/L for lead; 0.05, 0.1 and 0.2 mg/L for copper) were less than 7.5 and 7.1%. The recoveries of lead and copper spiked in human urine samples ranged from 96.7 to 108.1% and 93-96% for Pb and Cu, respectively. Furthermore, by comparing the results obtained using the developed on-line preconcentration method and graphite furnace atomic absorption spectrometry, we found the method is reliable for the determination of lead and copper in urine.
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