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Heterogeneity effects in direct XRF analysis of traces of heavy metals preconcentrated on polyurethane foam sorbents
Author(s) -
Török Szabina,
Braun Tibor,
Van Dyck Peter,
van Grieken René
Publication year - 1986
Publication title -
x‐ray spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.447
H-Index - 45
eISSN - 1097-4539
pISSN - 0049-8246
DOI - 10.1002/xrs.1300150104
Subject(s) - polyurethane , homogeneous , materials science , analytical chemistry (journal) , absorption (acoustics) , chemistry , sample preparation , ammonium , composite material , chromatography , physics , thermodynamics , organic chemistry
Trace amounts of heavy metals were preconcentrated on discs of polyurethane (PU) foam loaded with ammonium diethyldithiocarbamate (DDTC), to increase the sensitivity of XRF. Since the diameter of the cavities in the open‐cell PU foams reaches 30–300 μm, considerable heterogeneity effects might occur, which could reduce the accuracy of the method. The possible systematic error introduced by considering the sample to be homogeneous is calculated using the Berry et al. model. The calculations show that the underestimation of the absorption correction factor when considering the sample as being homogeneous is less than 2% for high‐Z elements when the sample thickness is at least 2 mm. The detection limits are also around the minima for this thickness.