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FUSEK, M. MICHÁLEK, J. VÁVROVÁ, M.
Originální název
Evaluation of contamination data with non-detects using censored distributions
Typ
článek v časopise ve Web of Science, Jimp
Jazyk
angličtina
Originální abstrakt
When measuring concentration of chemical compounds, we often have to deal with a~situation when the resulting values are found below the limit of detection or limit of quantification of the determination method. In order to statistically evaluate such data, the method of maximum likelihood considering doubly left-censored samples is applied. As a model distribution of measured concentrations, Weibull distribution is considered. Moreover, considering the asymptotic properties of maximum likelihood estimates, concentrations of chemicals can be compared using Wald's test based on the expected Fisher information matrix. Here we show that the described statistical method allows for a better evaluation of the obtained experimental data than commonly used methods where all values below the detection limits are replaced by a~constant. These methods are used for an analysis of the worldwide commonly used synthetic musk compounds (nitro and polycyclic) which were extracted from the fish samples caught upstream (Group 1) and downstream (Group 2) from a high-capacity wastewater treatment plant.
Klíčová slova
Doubly left-censored sample, maximum likelihood, musk compound, Wald's test, Weibull distribution
Autoři
FUSEK, M.; MICHÁLEK, J.; VÁVROVÁ, M.
Rok RIV
2015
Vydáno
3. 12. 2015
ISSN
1018-4619
Periodikum
Fresenius Environmental Bulletin
Ročník
24
Číslo
11c
Stát
Spolková republika Německo
Strany od
4165
Strany do
4172
Strany počet
8
BibTex
@article{BUT115693, author="Michal {Fusek} and Jaroslav {Michálek} and Milada {Vávrová}", title="Evaluation of contamination data with non-detects using censored distributions", journal="Fresenius Environmental Bulletin", year="2015", volume="24", number="11c", pages="4165--4172", issn="1018-4619" }