Inductively coupled plasma mass spectrometry (ICP-MS) is the most commonly used technique to deter- mine the abundances of trace elements in a wide range of geological materials. However, incomplete sample digestion...Inductively coupled plasma mass spectrometry (ICP-MS) is the most commonly used technique to deter- mine the abundances of trace elements in a wide range of geological materials. However, incomplete sample digestion, isobaric interferences and instrumental drift remain obvious problems that must be overcome in order to obtain precise and accurate results, For this reason, we have done many experi- ments and developed a set of simple, cost-effective and practical methods widely applicable for precise and rapid determination of trace element abundances in geological materials using ICP-MS. Commonly used high-pressure digestion technique is indeed effective in decomposing refractory phases, but this inevitably produces fluoride complexes that create new problems. We demonstrate that the fluoride complexes formed during high-pressure digestion can be readily re-dissolved using high-pressure vessel at 190 ℃ for only 2 h for 50 mg sample. In the case of isobaric interferences, although oxide (e.g., MO^+/M^+) and hydroxide (e.g., MO^+/M^+) productivity is variable between runs, the (MO^+/M^+)/(CeO^+/Ce^+) and (MOH^+/M^+)/(CeO^+/Ce^+) ratios remain constant, making isobaric interference correction for all other elements of interest straightforward, for which we provide an easy-to-use off-line procedure. We also show that mass-time-intensity drift curve is smooth as recognized previously, for which the correction can be readily done by analyzing a quality-control (QC) solution and using off-line Excel VBA procedure without internal standards. With these methods, we can produce data in reasonable agreement with rec- ommended values of international rock reference standards with a relative error of 〈8% and precision generally better than 5%. Importantly, compared to the widely used analytical practice, we can effectively save 〉60% of time (e.g., 〈24 h vs. 〉60 h).展开更多
Although human beings have come to understand and utilize coal for a very long history, no theoretical breakthrough in the study of coal structure has been made, which still needs continuous efforts of coal chemical w...Although human beings have come to understand and utilize coal for a very long history, no theoretical breakthrough in the study of coal structure has been made, which still needs continuous efforts of coal chemical workers. Based on the viewpoint of ‘vague/clear', the species classification and accurate analysis on coal were conducted by using the natural clustering all-component separation method. A more systematic and detailed coal embedded structure model theory which is suitable for coal of all ranks was developed from the previous one and a more complete theoretical system about the component and structure of coal was constructed. The whole establishment process of the theory was summarized and some of the main support data and analysis test results, including TEM, AFM, FTIR, GC/MS, MALDI/TOF/MS, DART/MSD, fractal analysis and so on were provided. The coal embedded structure theory fully considers both the identity and the particularity of all-rank coal, reflects the coal component and structure in the full range of coal rank, solves the systematic cognitive problem of coal component and structure on macro and micro level, and provides a valuable and meaningful theoretical approach for the coal processing and conversion technology.展开更多
Black shale samples were collected from Chimiari Khyber Pakthunkhawa region of Pakistan and were analyzed for elemental compositions. Atomic Absorption Spectrophotometry (AAS) was utilized for the determination of ele...Black shale samples were collected from Chimiari Khyber Pakthunkhawa region of Pakistan and were analyzed for elemental compositions. Atomic Absorption Spectrophotometry (AAS) was utilized for the determination of elements in the digested solutions. The analysis of black shale was performed precisely with relative standard deviation (RSD) lower than 2%. Results showed that the samples contained high concentrations of Ca (11.98 %), Al (7.09%), Fe (3.03%), Mg (0.59%) and Ti (0.58%).展开更多
基金supported by National Natural Science Foundation of China(41130314 and 41630968)Chinese Academy of Sciences Innovation Grant(Y42217101L)+1 种基金Qingdao National Laboratory for Marine Science and Technology(2015ASKJ03)Marine Geological Process and Environment(U1606401)
文摘Inductively coupled plasma mass spectrometry (ICP-MS) is the most commonly used technique to deter- mine the abundances of trace elements in a wide range of geological materials. However, incomplete sample digestion, isobaric interferences and instrumental drift remain obvious problems that must be overcome in order to obtain precise and accurate results, For this reason, we have done many experi- ments and developed a set of simple, cost-effective and practical methods widely applicable for precise and rapid determination of trace element abundances in geological materials using ICP-MS. Commonly used high-pressure digestion technique is indeed effective in decomposing refractory phases, but this inevitably produces fluoride complexes that create new problems. We demonstrate that the fluoride complexes formed during high-pressure digestion can be readily re-dissolved using high-pressure vessel at 190 ℃ for only 2 h for 50 mg sample. In the case of isobaric interferences, although oxide (e.g., MO^+/M^+) and hydroxide (e.g., MO^+/M^+) productivity is variable between runs, the (MO^+/M^+)/(CeO^+/Ce^+) and (MOH^+/M^+)/(CeO^+/Ce^+) ratios remain constant, making isobaric interference correction for all other elements of interest straightforward, for which we provide an easy-to-use off-line procedure. We also show that mass-time-intensity drift curve is smooth as recognized previously, for which the correction can be readily done by analyzing a quality-control (QC) solution and using off-line Excel VBA procedure without internal standards. With these methods, we can produce data in reasonable agreement with rec- ommended values of international rock reference standards with a relative error of 〈8% and precision generally better than 5%. Importantly, compared to the widely used analytical practice, we can effectively save 〉60% of time (e.g., 〈24 h vs. 〉60 h).
基金financial provided by the National Natural Science Foundation of China (Nos. 50474066, 50874108, 51274201, and 51674260)the Coal Joint Fund from National Natural Science Foundation of China and Shenhua Group Corporation Limited (No. U1361116)the National Basic Research Program of China (No. 2012CB214900)
文摘Although human beings have come to understand and utilize coal for a very long history, no theoretical breakthrough in the study of coal structure has been made, which still needs continuous efforts of coal chemical workers. Based on the viewpoint of ‘vague/clear', the species classification and accurate analysis on coal were conducted by using the natural clustering all-component separation method. A more systematic and detailed coal embedded structure model theory which is suitable for coal of all ranks was developed from the previous one and a more complete theoretical system about the component and structure of coal was constructed. The whole establishment process of the theory was summarized and some of the main support data and analysis test results, including TEM, AFM, FTIR, GC/MS, MALDI/TOF/MS, DART/MSD, fractal analysis and so on were provided. The coal embedded structure theory fully considers both the identity and the particularity of all-rank coal, reflects the coal component and structure in the full range of coal rank, solves the systematic cognitive problem of coal component and structure on macro and micro level, and provides a valuable and meaningful theoretical approach for the coal processing and conversion technology.
文摘Black shale samples were collected from Chimiari Khyber Pakthunkhawa region of Pakistan and were analyzed for elemental compositions. Atomic Absorption Spectrophotometry (AAS) was utilized for the determination of elements in the digested solutions. The analysis of black shale was performed precisely with relative standard deviation (RSD) lower than 2%. Results showed that the samples contained high concentrations of Ca (11.98 %), Al (7.09%), Fe (3.03%), Mg (0.59%) and Ti (0.58%).