Noble and active gases are released from geological samples during gas extraction for noble gas isotope analyses. The active gases should be removed before inletting to mass spectrometers for the analyses. The normal ...Noble and active gases are released from geological samples during gas extraction for noble gas isotope analyses. The active gases should be removed before inletting to mass spectrometers for the analyses. The normal noble gas preparation systems can clean up most geological samples. However, authigenic minerals from sedimentary rocks in oil/gas fields contain organic matter, which cannot be cleaned up by the normal preparation systems and thus influence the noble gas analyses. We introduce a novel gas purification system （PRC patent No. ZL201320117751.2）, which includes several reversible purification pumps with different absorbing and degassing temperatures. It can well clean up water steam, carbon dioxide and organic gas- es. Mica minerals are often used for 40Ar/39Ar dating. A muscovite sample （2082MS） which could not be cleaned up by the normal preparation system with two SAES NP10 getters, becomes the test sample for a comparative experiment in this study. The experiment is assigned into 4 sections with the organic gas removal system （OGRS） ＂Closed/Opened＂ in turn. When the OGRS is closed only with two NP10 getters for purification, the 40At intensities increase in curves with inlet time because of impurities, the 40Ar/39Ar dating results yield age errors about ＋2%-±1% （20-）. When the OGRS is opened for purification, in contrast, the 40Ar intensities decrease linearly with inlet time. This indicates that the gases have been cleaned up effectively, and the 40Ar/39Ar results yield ages with errors in ±0.4%. The OGRS is very helpful to obtain high-quality analysis data.展开更多
基金the National Science and Technology Major Project of China(Grant No.2011ZX05025-003-007)the 135 program of Chinese Academy of Sciences(Grant No.GIGCAS-135Y234151001)
文摘Noble and active gases are released from geological samples during gas extraction for noble gas isotope analyses. The active gases should be removed before inletting to mass spectrometers for the analyses. The normal noble gas preparation systems can clean up most geological samples. However, authigenic minerals from sedimentary rocks in oil/gas fields contain organic matter, which cannot be cleaned up by the normal preparation systems and thus influence the noble gas analyses. We introduce a novel gas purification system （PRC patent No. ZL201320117751.2）, which includes several reversible purification pumps with different absorbing and degassing temperatures. It can well clean up water steam, carbon dioxide and organic gas- es. Mica minerals are often used for 40Ar/39Ar dating. A muscovite sample （2082MS） which could not be cleaned up by the normal preparation system with two SAES NP10 getters, becomes the test sample for a comparative experiment in this study. The experiment is assigned into 4 sections with the organic gas removal system （OGRS） ＂Closed/Opened＂ in turn. When the OGRS is closed only with two NP10 getters for purification, the 40At intensities increase in curves with inlet time because of impurities, the 40Ar/39Ar dating results yield age errors about ＋2%-±1% （20-）. When the OGRS is opened for purification, in contrast, the 40Ar intensities decrease linearly with inlet time. This indicates that the gases have been cleaned up effectively, and the 40Ar/39Ar results yield ages with errors in ±0.4%. The OGRS is very helpful to obtain high-quality analysis data.
