Quality control and performance evaluation of k0-based neutron activation analysis at the Portuguese research reactor

Dũng, Hồ Mạnh; Freitas, M. C.; Blaauw, M.; Almeida, Susana Marta; Dionísio, I.; Canha, Nuno

doi:10.1016/j.nima.2010.04.003

Cited by 32 publications

(12 citation statements)

References 7 publications

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“…Moreover, the u-score test (Dung et al, 2010) was applied for all determined elements. The u-score test is a rating system to evaluate analyses of performance and includes uncertainties of the measurements and uncertainty of the assigned value.…”

Section: Quality Control Of Inaa Resultsmentioning

confidence: 99%

Indoor and Outdoor Biomonitoring Using Lichens at Urban and Rural Primary Schools

Canha¹,

Almeida²,

Freitas³

et al. 2014

Journal of Toxicology and Environmental Health, Part A

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Monitoring particulate matter (PM) and its chemical constituents in classrooms is a subject of special concern within the scientific community in order to control and minimize child exposure. Regulatory sampling methods have presented several limitations in their application to larger number of classrooms due to operational and financial constraints. Consequently, passive sampling methodologies using filters were developed for indoor sampling. However, such methodologies could not provide parallel information for outdoors, which is important to identify pollution sources and assess outdoor contribution to the indoors. Therefore, biomonitoring with transplanted lichens, a technique usually applied for outdoor studies, was used both indoor and outdoor of classrooms. Three main objectives were proposed, to (i) characterize simultaneously indoor and outdoor of classrooms regarding inorganic air pollutants, (ii) investigate spatial patterns of lichen conductivity, and (iii) assess pollution sources that contribute to a poor indoor air quality in schools. Lichens Flavoparmelia caperata were transplanted to indoor and outdoor of classrooms for 59 d. After exposure, electric conductivity of lichens leachate was measured to evaluate lichen vitality and cell damage. Outdoors lichen conductivity was higher near the main highways, and indoors there was great variability in levels, which indicates different emissions sources and different ventilation patterns. Chemical content of lichens was assessed by instrumental neutron activation analysis (INAA), and As, Br, Ca, Ce, Co, Cr, Cs, Eu, Fe, Hf, K, La, Na, Rb, Sb, Sc, Sm, Sr, Ta, Th, Yb, and Zn were determined. Element accumulation, crustal enrichment factors, and spatial variability of elements were analyzed and contaminants from anthropogenic sources, such as traffic (As, Sb, and Zn) and indoor chalk (Ca) found. Classrooms with potential indoor air quality problems were identified by presenting higher accumulations of inorganic pollutants in exposed biomonitors.

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Section: Quality Control Of Inaa Resultsmentioning

confidence: 99%

Indoor and Outdoor Biomonitoring Using Lichens at Urban and Rural Primary Schools

Canha¹,

Almeida²,

Freitas³

et al. 2014

Journal of Toxicology and Environmental Health, Part A

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“…Gamma Vision for Windows Model A66-B32, version 6.08, was used to evaluate the net peaks; the elemental concentrations were determined through k 0 -standardized instrumental neutron activation analysis (k 0 -INAA), and calculations were performed with the k 0 -IAEA software (version 5.22). The accuracy of the analytical method was evaluated with the certified reference material NIST-1633a, Coal Fly Ash, revealing results with an agreement of ±12 % Dung et al 2010). During the sampling campaign, blank filters were treated the same way as regular samples.…”

Section: Elementsmentioning

confidence: 99%

Source apportionment of indoor PM10 in Elderly Care Centre

Almeida-Silva

Faria

Saraga

et al. 2016

Environ Sci Pollut Res

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Source contribution to atmospheric particulate matter (PM) has been exhaustively modelled. However, people spend most of their time indoors where this approach is less explored. This evidence worsens considering elders living in Elderly Care Centres, since they are more susceptible. The present study aims to investigate the PM composition and sources influencing elderly exposure. Two 2-week sampling campaigns were conducted-one during early fall (warm phase) and another throughout the winter (cold phase). PM10 were collected with two TCR-Tecora(®) samplers that were located in an Elderly Care Centre living room and in the correspondent outdoor. Chemical analysis of the particles was performed by neutron activation analysis for element characterization, by ion chromatography for the determination of water soluble ions and by a thermal optical technique for the measurement of organic and elemental carbon. Statistical analysis showed that there were no statistical differences between seasons and environments. The sum of the indoor PM10 components measured in this work explained 57 and 53 % of the total PM10 mass measured by gravimetry in warm and cold campaigns, respectively. Outdoor PM10 concentrations were significantly higher during the day than night (p value < 0.05), as well as Ca(2+), Fe, Sb and Zn. The contribution of indoor and outdoor sources was assessed by principal component analysis and showed the importance of the highways and the airport located less than 500 m from the Elderly Care Centre for both indoor and outdoor air quality.

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“…Similarly, F was not determined in F standards with contents being lower or equal to 100 mg kg -1 , but the problem was solved by k 0 -CNAA and the bias between the experimental results and the assigned values was within 4% for 1,000 mg kg -1 and 9% for 100 mg kg -1 . Besides the determination of F and Se, k 0 -CNAA also allowed for the determination of other short-lived or detectable radionuclides such as Al, Ca, Cu, Dy, I, Mg, Ti, and V. Moreover, in Table 3, it turned out that CNAA allowed for the determination of I, Sr and U, all of which are difficult to measure in the samples by conventional INAA [12].…”

Section: Resultsmentioning

confidence: 99%

Development of the k 0-based cyclic neutron activation analysis for short-lived radionuclides

Dũng

Blaauw

Beasley

et al. 2011

J Radioanal Nucl Chem

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The k 0 -based cyclic neutron activation analysis (k 0 -CNAA) technique has been studied to explore the applicability at the Portuguese research reactor (RPI). In particular, for the determination of elements which form short-lived radionuclides, particularly fluorine ( 20 F, 11.16 s half-life) and selenium ( 77m Se, 17.36 s half-life) in polymer, biological and environmental samples. The detection limits obtained for F and Se were about 50 and 0.01 mg kg -1 , respectively, in the investigated materials. The timing parameters for the procedure were 10 to 20 s for irradiation, 5 s decay, 10 to 20 s counting, 5 s waiting and performed with eight cycles. The k 0 -IAEA program was modified to use millisecond time resolution for irradiation, decay and counting times as needed for interpreting k 0 -CNAA data in terms of concentration, accuracy and detection limit. The quality control of the procedure was performed by preparing a standard solution containing fluorine with different contents as well as using the certified reference materials containing selenium from which the bias between the results and the certified values were within 15% for most elements at the investigated content ranges. The analytical results for several other elements producing short-lived or detectable radionuclides, e.g., Al, Ca, Cl, Cu, Dy, I, Mg, Mn, Ti, and V were also obtained by the k 0 -CNAA procedure with accuracy within 12%.

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Quality control and performance evaluation of k0-based neutron activation analysis at the Portuguese research reactor

Cited by 32 publications

References 7 publications

Indoor and Outdoor Biomonitoring Using Lichens at Urban and Rural Primary Schools

Indoor and Outdoor Biomonitoring Using Lichens at Urban and Rural Primary Schools

Source apportionment of indoor PM10 in Elderly Care Centre

Development of the k 0-based cyclic neutron activation analysis for short-lived radionuclides

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