A Study on the Factors Causing Analytical Errors through the Estimation of Uncertainty for Cadmium and Lead Analysis in Tomato Paste
2011
Kim, J.Y., National Academy of Agricultural Science, RDA, Suwon, Republic of Korea | Kim, Y.J., Seoul National University, Seoul, Republic of Korea | Yoo, J.H., National Academy of Agricultural Science, RDA, Suwon, Republic of Korea | Lee, J.H., National Academy of Agricultural Science, RDA, Suwon, Republic of Korea | Kim, M.J., National Academy of Agricultural Science, RDA, Suwon, Republic of Korea | Kang, D.W., National Academy of Agricultural Science, RDA, Suwon, Republic of Korea | Im, G.J., National Academy of Agricultural Science, RDA, Suwon, Republic of Korea | Hong, M.K., National Academy of Agricultural Science, RDA, Suwon, Republic of Korea | Shin, Y.J., Dankook University, Cheonan, Republic of Korea | Kim, W.I., National Academy of Agricultural Science, RDA, Suwon, Republic of Korea
BACKGROUND: This study aimed to estimate the measurement uncertainty associated with determination of cadmium and lead from tomato paste by ICP/MS. The sources of measurement uncertainty (i.e. sample weight, final volume, standard weight, purity, molecular weight, working standard solution, calibration curve, recovery and repeatability) in associated with the analysis of cadmium and lead were evaluated. METHODS AND RESULTS: The guide to the expression of uncertainty was used for the GUM (Guide to the expression of Uncertainty in Measurement) and Draft EURACHEM/CITAC (EURACHEM: A network of organization for analytical chemistry in Europe/Co-Operation on International Traceability in Analytical Chemistry) Guide with mathematical calculation and statistical analysis. The uncertainty components were evaluated by either Type A or Type B methods and the combined standard uncertainty were calculated by statistical analysis using several factors. Expected uncertainty of cadmium and lead was 0.106±0.015 mg/kg (k=2.09) and 0.302±0.029 mg/kg (k=2.16), on basis of 95% confidence of Certified Reference Material (CRM) which was within certification range of 0.112±0.007 mg/kg for cadmium (k=2.03) and 0.316±0.021 mg/kg for lead (k=2.01), respectively. CONCLUSION(s): The most influential components in the uncertainty of heavy metals analysis were confirmed as recovery, standard calibration curve and standard solution were identified as the most influential components causing uncertainty of heavy metal analysis. Therefore, more careful consideration is required in these steps to reduce uncertainty of heavy metals analysis in tomato paste.
显示更多 [+] 显示较少 [-]