caa a22 4500 605465460 CHVBK 20210128100302.0 cr unu---uuuuu 210128e20150201xx s 000 0 eng 10.1007/s00769-014-1098-8 doi (NATIONALLICENCE)springer-10.1007/s00769-014-1098-8 Evaluation of acid matrix effects in the determination of major elements in biomass by atomic absorption spectrometry from an environmentally friendly point of view [Elektronische Daten] [Paula Teixeira, Sandra Calisto, Helena Lopes, Maria Trancoso] The estimation of major element content in solid biofuels is required for prediction and prevention of eventual ash-related problems during combustion. These analyses have to be achieved with minimum impact on the environment. The quantitation of Al, Ca, Mg, Na, K, Fe, Si and Mn in biofuels was carried out according to EN 15290 using acid decomposition of solid samples followed by atomic absorption spectrometry (AAS). A microwave-assisted acid digestion with a HNO3/H2O2/HF mixture was used, followed by HF complexation using H3BO3. Due to the presence of tetrafluoroboric acid complex in the digestion solution, matrix effects were noticed during elemental quantification by AAS. Standard addition calibration methods did not compensate for this matrix effect. Matrix effects that constrain an analytical response may be overcome by applying the procedure used for samples to the calibration standards using the same reagents. However, this entails using large amounts of toxic reagents. In this work, the fluoric-boric acid matrix matching was assessed statistically using one-way ANOVA tests. For the seven groups of nitric acid and reagent blank (HNO3/H2O2/HF/H3BO3) mixtures used, ranging from 0 to 1 volume ratios, no significant differences were observed for Si, Al, Fe and Mn. The calculated F values were lower than the critical value, F 6,14=2.85 (p=0.05). However, for Ca, Mg, Na and K, significant differences were observed. Tenfold dilution was used for samples where the mass fraction exceeded the analytical dynamic range of the AAS instrument. The calibration solutions were prepared using the reagent blanks in the same proportion thus decreasing the amount of acids used. The procedure was validated using SRM 1573a—tomato leaves—purchased from the National Institute of Standards and Technology. Target recoveries of (1±0.1) were achieved. Springer-Verlag Berlin Heidelberg, 2014 Acid matrix matching evaluation nationallicence Major elements nationallicence Flame atomic absorption spectrometry nationallicence Traceability to SRM nationallicence Internal and external quality control nationallicence Measurement uncertainty nationallicence Assessment of acid matrix reagents consumption nationallicence Teixeira Paula Laboratory National of Energy and Geology (LNEG), Lisbon, Portugal aut Calisto Sandra Laboratory National of Energy and Geology (LNEG), Lisbon, Portugal aut Lopes Helena Laboratory National of Energy and Geology (LNEG), Lisbon, Portugal aut Trancoso Maria Laboratory National of Energy and Geology (LNEG), Lisbon, Portugal aut Accreditation and Quality Assurance Springer Berlin Heidelberg 20/1(2015-02-01), 67-74 0949-1775 20:1<67 2015 20 769 https://doi.org/10.1007/s00769-014-1098-8 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s00769-014-1098-8 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Teixeira Paula Laboratory National of Energy and Geology (LNEG), Lisbon, Portugal aut NATIONALLICENCE 700 1- Calisto Sandra Laboratory National of Energy and Geology (LNEG), Lisbon, Portugal aut NATIONALLICENCE 700 1- Lopes Helena Laboratory National of Energy and Geology (LNEG), Lisbon, Portugal aut NATIONALLICENCE 700 1- Trancoso Maria Laboratory National of Energy and Geology (LNEG), Lisbon, Portugal aut NATIONALLICENCE 773 0- Accreditation and Quality Assurance Springer Berlin Heidelberg 20/1(2015-02-01), 67-74 0949-1775 20:1<67 2015 20 769