Investigation into Alternative Sample Preparation Techniques for the Determination of Heavy Metals in Stationary Source Emission Samples Collected on Quartz Filters

Sensors

Sharon L. Goddard¹ 

关键词: stationary source emissions;    heavy metals;    quartz filters;    hydrofluoric acid;    fluoroboric acid;    aqua regia;   

DOI  :  10.3390/s141121676

来源: mdpi

【 摘 要 】

Monitoring stationary source emissions for heavy metals generally requires the use of quartz filters to collect samples because of the high temperature and high moisture sampling environment. The documentary standard method sample preparation technique in Europe, EN 14385, uses digestion in hydrofluoric acid and nitric acid (HF/HNO₃) followed by complexing with boric acid (H₃BO₃) prior to analysis. However, the use of this method presents a number of problems, including significant instrumental drift during analysis caused by the matrix components, often leading to instrument breakdown and downtime for repairs, as well as posing significant health and safety risks. The aim of this work was to develop an alternative sample preparation technique for emissions samples on quartz filters. The alternative techniques considered were: (i) acid digestion in a fluoroboric acid (HBF₄) and HNO₃ mixture and (ii) acid extraction in an aqua regia (AR) mixture (HCl and HNO₃). Assessment of the effectiveness of these options included determination of interferences and signal drift, as well as validating the different methods by measurement of matrix certified reference materials (CRMs), and comparing the results obtained from real test samples and sample blanks to determine limits of detection. The results showed that the HBF₄/HNO₃ mixture provides the most viable alternative to the documentary standard preparation technique.

【 授权许可】

CC BY   
© 2014 by the authors; licensee MDPI, Basel, Switzerland.