A Microwave Digestion Technique for the Analysis of Rare Earth Elements, Thorium and Uranium in Geochemical Certified Reference Materials and Soils by Inductively Coupled Plasma Mass Spectrometry

• Published in: Molecules (Basel, Switzerland) Vol. 25; no. 21; p. 5178
• Main Authors: Kasar, Sharayu, Murugan, Rajamanickam, Arae, Hideki, Aono, Tatsuo, Sahoo, Sarata Kumar
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 06.11.2020; MDPI
• Subjects: Accuracy; Acids; chemical digestion; Chernobyl Nuclear Accident; Contamination; Depleted uranium; Digestion; Emission spectroscopy; Fukushima Nuclear Accident; Geochemistry; Geological surveys; Heterogeneity; ICP-MS; Inductively coupled plasma mass spectrometry; Japan; JSd-2; Mass spectrometry; Mass Spectrometry - methods; Mass Spectrometry - standards; Mass spectroscopy; Metals, Rare Earth - analysis; Methods; Microwaves; Nuclear accidents & safety; Nuclear power plants; Quality control; Radioisotopes; Rare earth elements; Reference materials; Reference Standards; Republic of Belarus; Scientific imaging; Serbia; Soil - chemistry; Soil analysis; Soil contamination; Soil Pollutants - analysis; Soils; Standard deviation; Thorium; Thorium - analysis; Trace elements; Ukraine; Uranium; Uranium - analysis; Republic of Belarus; Serbia; Japan; Ukraine; chemical digestion; JSd-2; ICP-MS; Th; U; rare earth elements
• ISSN: 1420-3049; 1420-3049
• DOI: 10.3390/molecules25215178

Two different digestion methods-microwave digestion (Mw) and Savillex digestion (Sx)-were used to evaluate the best quality control for analysis of the rare earth elements, Th and U in the geochemical certified reference material JSd-2, supplied by the Geological Survey of Japan (GSJ). The analysis of trace elements was carried out using inductively coupled plasma mass spectrometry (ICP-MS). The digestion recovery was > 90% for almost all elements by both methods. Mw-4 (four repeats of the microwave digestion) was found to be more effective and faster than Sx. In order to evaluate the efficiency of Mw-4, three other GSJ certified reference materials, JLk-1, JB-1 and JB-3, as well as five different soil samples from Belarus, Japan, Serbia and Ukraine were also analyzed. The Mw-4 method was seen to be promising for complete digestion and recovery of most of the elements. The U/Th ratio showed some heterogeneity for Ukraine and Serbia soils affected by Chernobyl nuclear power plant accident and depleted uranium contamination, respectively. This method can be successfully applied to any type of soils for elemental analyses.