Determination of Rare Earth Elements in Ultra-fine Rock and Soil Samples by ICP-MS Using Microwave Digestion
BACKGROUND The sampling weight can be as low as milligram level when the contents of rare earth elements in rock and soil samples are determined by inductively coupled plasma-mass spectrometry (ICP-MS). However, the size of 200 mesh samples requires 100mg to ensure representativeness, which makes it...
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| Format: | Article |
| Language: | English |
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Science Press, PR China
2020-01-01
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| Series: | Yankuang ceshi |
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| Online Access: | http://www.ykcs.ac.cn/en/article/doi/10.15898/j.cnki.11-2131/td.201904010043 |
| _version_ | 1828065023814008832 |
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| author | WANG Na XU Tie-min WEI Shuang WANG Jia-song ZENG Jiang-ping ZHANG Nan |
| author_facet | WANG Na XU Tie-min WEI Shuang WANG Jia-song ZENG Jiang-ping ZHANG Nan |
| author_sort | WANG Na |
| collection | DOAJ |
| description | BACKGROUND The sampling weight can be as low as milligram level when the contents of rare earth elements in rock and soil samples are determined by inductively coupled plasma-mass spectrometry (ICP-MS). However, the size of 200 mesh samples requires 100mg to ensure representativeness, which makes it difficult for ICP-MS to make full use of its advantages of high sensitivity and small sampling volume. OBJECTIVES To establish the method for the determination of rare earth elements in ultra-fine rock and soil samples by ICP-MS with microwave digestion. METHODS A method was developed for the determination of rare earth elements in ultra-fine rock and soil samples by ICP-MS with microwave digestion. The ultra-fine rock and soil samples were prepared by the planetary superfine pulverizing machine with wet grinding. Some parameters influencing the preparation of ultra-fine rock and soil samples, including grinding method, grinding time and the proportion of grinding balls were optimized. Microwave digestion of ultrafine-grained rock and soil samples in a nitric acid-hydrofluoric acid-hydrogen peroxide solution system, the sampling amount was reduced to 5mg, the total acid amount was reduced to 0.25mL and the digestion time was reduced to 25 minutes. RESULTS The results indicated that the samples were best refined when the wet-milling was adopted with ethanol as a dispersant and the milling time was 10 minutes and 15 minutes for 200 mesh soil and rock samples, respectively. The material ratios were 7g materials, 500 grinding balls, 45mL dispersants for the preparation of ultra-fine soil samples, whereas 5g materials, 500 grinding balls, 45mL dispersants for the preparation of ultra-fine rock samples. The particle size distribution D95 of soil standard substance GBW07404 and GBW07447 can be as low as 7.51μm and 7.05μm, and the D95 of rock standard substance GBW07104 and GBW07121 can be 8.42μm and 8.30μm under the optimized conditions. Microwave digestion of ultrafine-grained rock sample GBW07104 in a nitric acid-hydrofluoric acid-hydrogen peroxide solution system, the sampling amount was reduced to 5mg, the total acid amount was reduced to 0.25mL, the digestion time was reduced to 25 minutes, and the measured value of rare earth elements was consistent with the certified value with the relative standard deviation is between 1.64% and 5.21%. CONCLUSIONS This method was used for the detection of rare earth elements in other ultra-fine standard materials (GBW07404, GBW07447 and GBW07121), which yielded the relative standard deviation of 0.17%-6.60%, meeting the first criterion of Geology and Minerals Laboratory Testing Quality Management Standards. |
| first_indexed | 2024-04-10T23:07:46Z |
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| id | doaj.art-4ea50745e60c47e897e7dfb39f25fbe4 |
| institution | Directory Open Access Journal |
| issn | 0254-5357 |
| language | English |
| last_indexed | 2024-04-10T23:07:46Z |
| publishDate | 2020-01-01 |
| publisher | Science Press, PR China |
| record_format | Article |
| series | Yankuang ceshi |
| spelling | doaj.art-4ea50745e60c47e897e7dfb39f25fbe42023-01-13T09:59:58ZengScience Press, PR ChinaYankuang ceshi0254-53572020-01-01391687610.15898/j.cnki.11-2131/td.201904010043ykcs-39-1-68Determination of Rare Earth Elements in Ultra-fine Rock and Soil Samples by ICP-MS Using Microwave DigestionWANG Na0XU Tie-min1WEI Shuang2WANG Jia-song3ZENG Jiang-ping4ZHANG Nan5Tianjin Center of Geological Survey, China Geological Survey, Tianjin 300170, ChinaTianjin Center of Geological Survey, China Geological Survey, Tianjin 300170, ChinaTianjin Center of Geological Survey, China Geological Survey, Tianjin 300170, ChinaTianjin Center of Geological Survey, China Geological Survey, Tianjin 300170, ChinaTianjin Center of Geological Survey, China Geological Survey, Tianjin 300170, ChinaTianjin Center of Geological Survey, China Geological Survey, Tianjin 300170, ChinaBACKGROUND The sampling weight can be as low as milligram level when the contents of rare earth elements in rock and soil samples are determined by inductively coupled plasma-mass spectrometry (ICP-MS). However, the size of 200 mesh samples requires 100mg to ensure representativeness, which makes it difficult for ICP-MS to make full use of its advantages of high sensitivity and small sampling volume. OBJECTIVES To establish the method for the determination of rare earth elements in ultra-fine rock and soil samples by ICP-MS with microwave digestion. METHODS A method was developed for the determination of rare earth elements in ultra-fine rock and soil samples by ICP-MS with microwave digestion. The ultra-fine rock and soil samples were prepared by the planetary superfine pulverizing machine with wet grinding. Some parameters influencing the preparation of ultra-fine rock and soil samples, including grinding method, grinding time and the proportion of grinding balls were optimized. Microwave digestion of ultrafine-grained rock and soil samples in a nitric acid-hydrofluoric acid-hydrogen peroxide solution system, the sampling amount was reduced to 5mg, the total acid amount was reduced to 0.25mL and the digestion time was reduced to 25 minutes. RESULTS The results indicated that the samples were best refined when the wet-milling was adopted with ethanol as a dispersant and the milling time was 10 minutes and 15 minutes for 200 mesh soil and rock samples, respectively. The material ratios were 7g materials, 500 grinding balls, 45mL dispersants for the preparation of ultra-fine soil samples, whereas 5g materials, 500 grinding balls, 45mL dispersants for the preparation of ultra-fine rock samples. The particle size distribution D95 of soil standard substance GBW07404 and GBW07447 can be as low as 7.51μm and 7.05μm, and the D95 of rock standard substance GBW07104 and GBW07121 can be 8.42μm and 8.30μm under the optimized conditions. Microwave digestion of ultrafine-grained rock sample GBW07104 in a nitric acid-hydrofluoric acid-hydrogen peroxide solution system, the sampling amount was reduced to 5mg, the total acid amount was reduced to 0.25mL, the digestion time was reduced to 25 minutes, and the measured value of rare earth elements was consistent with the certified value with the relative standard deviation is between 1.64% and 5.21%. CONCLUSIONS This method was used for the detection of rare earth elements in other ultra-fine standard materials (GBW07404, GBW07447 and GBW07121), which yielded the relative standard deviation of 0.17%-6.60%, meeting the first criterion of Geology and Minerals Laboratory Testing Quality Management Standards.http://www.ykcs.ac.cn/en/article/doi/10.15898/j.cnki.11-2131/td.201904010043rocksoilrare earth elementsultra-fine sample preparationwet-millingethanolmicrowave digestioninductively coupled plasma-mass spectrometry |
| spellingShingle | WANG Na XU Tie-min WEI Shuang WANG Jia-song ZENG Jiang-ping ZHANG Nan Determination of Rare Earth Elements in Ultra-fine Rock and Soil Samples by ICP-MS Using Microwave Digestion Yankuang ceshi rock soil rare earth elements ultra-fine sample preparation wet-milling ethanol microwave digestion inductively coupled plasma-mass spectrometry |
| title | Determination of Rare Earth Elements in Ultra-fine Rock and Soil Samples by ICP-MS Using Microwave Digestion |
| title_full | Determination of Rare Earth Elements in Ultra-fine Rock and Soil Samples by ICP-MS Using Microwave Digestion |
| title_fullStr | Determination of Rare Earth Elements in Ultra-fine Rock and Soil Samples by ICP-MS Using Microwave Digestion |
| title_full_unstemmed | Determination of Rare Earth Elements in Ultra-fine Rock and Soil Samples by ICP-MS Using Microwave Digestion |
| title_short | Determination of Rare Earth Elements in Ultra-fine Rock and Soil Samples by ICP-MS Using Microwave Digestion |
| title_sort | determination of rare earth elements in ultra fine rock and soil samples by icp ms using microwave digestion |
| topic | rock soil rare earth elements ultra-fine sample preparation wet-milling ethanol microwave digestion inductively coupled plasma-mass spectrometry |
| url | http://www.ykcs.ac.cn/en/article/doi/10.15898/j.cnki.11-2131/td.201904010043 |
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