World Health Organization international intercalibration study on dioxins and furans in human milk and blood

Abstract

Under the sponsorship of the World Health Organization (WHO), an interlaboratory calibration on the analysis of PCDD/PCDFs in human milk and blood was carried out which included 19 laboratories from 14 countries. The study design involved the analysis of three samples of each matrix in triplicate. Selected samples were spiked with native standards of certain 2,3,7,8-substituted congeners at concentrations known only to WHO staff. The study design resulted in approximately 4000 individual pieces of PCDD/PCDF data generated by a variety of analytical methods, at various concentrations, and by laboratories of widely different experience. This was, by considerable margin, the largest study which allowed for the direct comparison of laboratory and method performance. The results of statistical analysis of this data base addresses the effect on data quality of clean up methods, instrumental methods, analyte concentration, laboratory QA programs, and laboratory experience. The study has shown that the laboratory is the single most important determinant of data precision and accuracy. The method of analyte enrichment (sample clean up), analyte measurement [gas chromatography/mass spectrometry (GC/MS) protocol], and analyte concentration have weaker correlations with data quality.

Estimation of the Cumulated Exposure to Polychlorinated Dibenzo-p-dioxins/furans and Standardized Mortality Ratio Analysis of Cancer Mortality by Dose in an Occupationally Exposed Cohort

“…The basic methods followed in this si follow Manz et (18) and the adipose tissue concentrations area under the curve above background at time, are described in Beck et al (19). The the end of the follow-up.…”

Analysis of Persistent Organic Pollutants at Sub-Femtogram Levels Using a High-Power Picosecond Laser for Multiphoton Ionization in Conjunction with Gas Chromatography/Time-of-Flight Mass Spectrometry

“…6,7 One of the more successful methods is high-resolution gas chromatography combined with high-resolution mass spectrometry (HRGC/HRMS) with electron ionization (EI), a technique that is frequently used for the determination of POPs. [8][9][10] However, the EI technique utilized in HRGC/HRMS ionizes many compounds simultaneously, even interfering species, some of which can have nearly identical retention times to the analytes in GC. In addition, the numerous fragment species that appear in the mass spectrum make the determination of the analytes difficult.…”

Determination of polychlorinated dibenzo‐p‐dioxins, dibenzofurans, and biphenyls by gas chromatography/mass spectrometry in the negative chemical ionization mode with different reagent gases

“…Nowadays, only a few analytical laboratories can afford performing analyses for any PCDDs and PCDFs, and particularly quantifying them in the samples of different origin. Such analyses are very expensive, laborious, and time-consuming, and the results depend highly on many factors, such as analyte concentration, clean-up method, the use of high-or low-resolution mass spectrometry, and the experience of a laboratory in the dioxin field (Stephens et al, 1992). Therefore, the development of a method for the rapid and comparatively low-cost screening is a problem to be solved.…”