A new method for high-precision measurements of stable (δ88/86Sr) and radiogenic (87Sr/86Sr) Sr isotope ratios was developed on the MC-ICP-MS using a standard-sample-standard bracketing protocol. By carefully monitor...A new method for high-precision measurements of stable (δ88/86Sr) and radiogenic (87Sr/86Sr) Sr isotope ratios was developed on the MC-ICP-MS using a standard-sample-standard bracketing protocol. By carefully monitoring and controlling the accumulation of the on-peak backgrounds (i.e. the carryover memory) on the instrument, our method can provide an external precision of around 0.010‰ to 0.014‰ for 88/86 Sr measurements. Such precision is comparable to that achieved by double-spike TIMS method (DS-TIMS), and 2-3 times better than those of the previously reported results by MC-ICP-MS without spiking. The results of the standard seawater IAPSO are also identical to those by DS-TIMS. However, our method is more advantageous, efficient and convenient to use for routine Sr isotopic analysis than the DS-TIMS method as there is no need to prepare and calibrate the 84Sr-87 Sr double spike. Using this method, we measured the δ88/86Sr values in a series of international geological rock standards, which show large variability, with the lowest value (0.20‰) registered in JG-2, a terrestrial granite, and the highest value (0.539‰) in UB-N, a serpentinite. This may provide an additional means for isotopic characterization of geological processes, adding a new dimension over the traditional use of radiogenic Sr isotopic ratio 87Sr/86Sr.展开更多
目的建立同位素稀释液相色谱串联质谱(isotope dilution chromatography tandem mass spectrometry,ID-LC/MS)测定人血清同型半胱氨酸(Hcy)参考方法,并运用于临床实验室室间质评(external quality assessment,EQA)样本靶值的确立。方法...目的建立同位素稀释液相色谱串联质谱(isotope dilution chromatography tandem mass spectrometry,ID-LC/MS)测定人血清同型半胱氨酸(Hcy)参考方法,并运用于临床实验室室间质评(external quality assessment,EQA)样本靶值的确立。方法参照国际检验医学溯源联合委员会(the Joint Committee for Traceability in Laboratory Medicine,JCTLM)推荐方法,建立本实验室Hcy参考方法,并对所建方法的精密度、正确度、特异性、残留、基质效应等进行评估,并将建立的参考方法用于上海地区2018年度第二次EQA样本Hcy靶值的确立。结果该方法3 d 3批次检测12.5μmol/L和37.4μmol/L样本,批间CV分别为1.03%和2.10%,精密度较好;检测美国国家标准和技术研究院(National Institute of Standards and Technology,NIST)标准参考物质(standard reference material,SRM)1955均在规定的不确定度范围内;无基质效应和携带污染。2018年第二次EQA数据显示国产试剂组均值低于参考方法赋值结果,进口试剂组均值高于参考方法赋值结果。结论建立的ID-LC/MS/MS测定血清Hcy参考方法精密度、正确度、特异性均较好,无分析物残留,有望在临床实验室Hcy测定的量值溯源中发挥一定作用。展开更多
基金supported by the Chinese Ministry of Science and Technology Special Scheme (2009CB421206 and 2010CB808900)the Knowledge Innovation Program of the Chinese Academy of Sciences (KZCX2-YW-138)+1 种基金the National Natural Science Foundation of China (40973008 and 41173006)contribution No.IS-1616 from GIGCAS
文摘A new method for high-precision measurements of stable (δ88/86Sr) and radiogenic (87Sr/86Sr) Sr isotope ratios was developed on the MC-ICP-MS using a standard-sample-standard bracketing protocol. By carefully monitoring and controlling the accumulation of the on-peak backgrounds (i.e. the carryover memory) on the instrument, our method can provide an external precision of around 0.010‰ to 0.014‰ for 88/86 Sr measurements. Such precision is comparable to that achieved by double-spike TIMS method (DS-TIMS), and 2-3 times better than those of the previously reported results by MC-ICP-MS without spiking. The results of the standard seawater IAPSO are also identical to those by DS-TIMS. However, our method is more advantageous, efficient and convenient to use for routine Sr isotopic analysis than the DS-TIMS method as there is no need to prepare and calibrate the 84Sr-87 Sr double spike. Using this method, we measured the δ88/86Sr values in a series of international geological rock standards, which show large variability, with the lowest value (0.20‰) registered in JG-2, a terrestrial granite, and the highest value (0.539‰) in UB-N, a serpentinite. This may provide an additional means for isotopic characterization of geological processes, adding a new dimension over the traditional use of radiogenic Sr isotopic ratio 87Sr/86Sr.
文摘目的建立同位素稀释液相色谱串联质谱(isotope dilution chromatography tandem mass spectrometry,ID-LC/MS)测定人血清同型半胱氨酸(Hcy)参考方法,并运用于临床实验室室间质评(external quality assessment,EQA)样本靶值的确立。方法参照国际检验医学溯源联合委员会(the Joint Committee for Traceability in Laboratory Medicine,JCTLM)推荐方法,建立本实验室Hcy参考方法,并对所建方法的精密度、正确度、特异性、残留、基质效应等进行评估,并将建立的参考方法用于上海地区2018年度第二次EQA样本Hcy靶值的确立。结果该方法3 d 3批次检测12.5μmol/L和37.4μmol/L样本,批间CV分别为1.03%和2.10%,精密度较好;检测美国国家标准和技术研究院(National Institute of Standards and Technology,NIST)标准参考物质(standard reference material,SRM)1955均在规定的不确定度范围内;无基质效应和携带污染。2018年第二次EQA数据显示国产试剂组均值低于参考方法赋值结果,进口试剂组均值高于参考方法赋值结果。结论建立的ID-LC/MS/MS测定血清Hcy参考方法精密度、正确度、特异性均较好,无分析物残留,有望在临床实验室Hcy测定的量值溯源中发挥一定作用。
