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Evaluation of the Measurement Uncertainty from the Standard Operating Procedures(SOP) of the National Environmental Specimen Bank
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 Title & Authors
Evaluation of the Measurement Uncertainty from the Standard Operating Procedures(SOP) of the National Environmental Specimen Bank
Lee, Jongchun; Lee, Jangho; Park, Jong-Hyouk; Lee, Eugene; Shim, Kyuyoung; Kim, Taekyu; Han, Areum; Kim, Myungjin;
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Five years have passed since the first set of environmental samples was taken in 2011 to represent various ecosystems which would help future generations lead back to the past environment. Those samples have been preserved cryogenically in the National Environmental Specimen Bank(NESB) at the National Institute of Environmental Research. Even though there is a strict regulation (SOP, standard operating procedure) that rules over the whole sampling procedure to ensure each sample to represent the sampling area, it has not been put to the test for the validation. The question needs to be answered to clear any doubts on the representativeness and the quality of the samples. In order to address the question and ensure the sampling practice set in the SOP, many steps to the measurement of the sample, that is, from sampling in the field and the chemical analysis in the lab are broken down to evaluate the uncertainty at each level. Of the 8 species currently taken for the cryogenic preservation in the NESB, pine tree samples from two different sites were selected for this study. Duplicate samples were taken from each site according to the sampling protocol followed by the duplicate analyses which were carried out for each discrete sample. The uncertainties were evaluated by Robust ANOVA; two levels of uncertainty, one is the uncertainty from the sampling practice, and the other from the analytical process, were then compiled to give the measurement uncertainty on a measured concentration of the measurand. As a result, it was confirmed that it is the sampling practice not the analytical process that accounts for the most of the measurement uncertainty. Based on the top-down approach for the measurement uncertainty, the efficient way to ensure the representativeness of the sample was to increase the quantity of each discrete sample for the making of a composite sample, than to increase the number of the discrete samples across the site. Furthermore, the cost-effective approach to enhance the confidence level on the measurement can be expected from the efforts to lower the sampling uncertainty, not the analytical uncertainty. To test the representativeness of a composite sample of a sampling area, the variance within the site should be less than the difference from duplicate sampling. For that, a criterion, (across the site variance) <(variance at the sampling location) was proposed. In light of the criterion, the two representative samples for the two study areas passed the requirement. In contrast, whenever the variance of among the sampling locations (i.e. across the site) is larger than the sampling variance, more sampling increments need to be added within the sampling area until the requirement for the representativeness is achieved.
representativeness of a sample;small-scale heterogeneity;analysis of variance;
 Cited by
국가환경시료은행 활엽 시료를 활용한 지역별 대기침적 오염물질 모니터링 활용성 검토,이종천;이장호;박종혁;이유진;심규영;장희연;

환경영향평가, 2016. vol.25. 6, pp.532-541 crossref(new window)
Applicability test of broad leaf samples stored at the NESB for biomonitoring of airborne pollutants, Journal of Environmental Impact Assessment, 2016, 25, 6, 532  crossref(new windwow)
국립환경과학원. 2013. 대기환경연보, 163-178.

김명진, 유병호, 이민효, 김태규, 이정연, 최태영, 이중효, 이선미, 이석조, 이종천, 이철우. 2007. 국가환경시료은행 표준운영체계 구축 연구(I), 국립환경과학원 보고서.

박기학. 1992. 교통량 과밀 도로주변의 토양과 가로수, 대기중 Pb, Cu, Zn 중금속 농도와 그 상관성에 관한 연구, 한국환경위생학회지, 18(2), 19-25.

이상희, 한아름, 이종천, 이장호, 이유진, 김기동. 2013. 침엽수 시료의 중금속 함량에 영향을 미치는 지화학적 특성 및 입자상 성분 연구, 국립환경과학원 보고서.

이장호, 이종천, 바데 라빈드라, 한아름, 이유진, 김민성, 김명진, 오길종. 2012. 국가환경시료은행 시료채취 및 처리 표준운영절차 활용연구(III), 국립환경과학원 보고서.

추미경, 김규한, 이진수, 전효택. 2005. 서울지역 가로수 토양과 은행나무 잎 중의 중금속 원소들의 지구화학적 분산과 오염특성, 자원환경지질학회지, 38(3), 221-236.

AMC. 1989. Robust statistics-how not to reject outliers-Part 1. Basic concepts. Analyst, 114, 1693-1697. crossref(new window)

Appenroth KJ. 2010. Definition of "Heavy Metals" and their role in biological systems. In: I. Sherameti and A. Varma (eds.). Soil Heavy Metals, Soil Biology. 19, 19-29. crossref(new window)

ISO. 1993. Guide to the expression of uncertainty in measurement. 1st ed. International Organisation for Standardisation. Geneva, Switzerland.

Lyn JA, Ramsey MH, Coad DS, Damant AP, Wood R, Boon KA. 2007. The duplicate method of uncertainty estimation: are eight targets enough?, The Analyst 132(11), 1147-1152. crossref(new window)

Ramsey MH, Watkins PJ, Sams MS. 1998. Estimation of measurement uncertainty for in situ borehole determinations using a geochemical logging tool. Geological Society. Special Publication, 136, 53-63. crossref(new window)

Thompson M. 1995. Uncertainty in an uncertain world. Analyst, 120, 117N-118N. crossref(new window)

Wagner G. 1993. Plants and soils as specimen types from terrestrial ecosystems in the environmental specimen banking program of the Federal Republic of Germany. Science of the Total Environment, 139-140, 213-224. crossref(new window)