Research of Isotopic Reference Material for Improvement of Measurement Precision of Isotopic Ratios in Space and Earth Sciences

提高空间与地球科学同位素比值测量精度的同位素标准物质研究

• 批准号: 08304035
• 负责人: TANAKA Tsuyoshi
• 金额: $ 4.99万
• 依托单位: Nagoya University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (A)
• 财政年份: 1996
• 资助国家: 日本
• 起止时间: 1996 至 1997
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-08304035/
• 关键词: SPACE SCIENCE; EARTH SCIENCE; ISOTOPE; REAGENT; ISOTOPIC REFERENCE; MASS SPECTROMETRY; PRECISION; NEODYMIUM

Neodymium isotopic standard requires low impurity. In addition, (1) it should have a high ^<143>Nd/^<144>Nd ratio because of high ratios in island-arc samples generally researched in Japan and (2) should have low rare-earth impurities because of the reduction of isobaric interference by ^<142>Ce and ^<144>Sm. Isotopic ratios and rare-earth impurities were examined in high purity neodymium oxides prepared by six chemical companies, SPEC,JMC,CERAC,MERCK,ShinEtsu and Mitsuwa. The reagent of the ShinEtsu company is preferable. Two bottles of 1kg each, of neodymium oxide reagent from the same lot, were bought from the ShinEtsu company and defined as split 1 and split 2. Upper part of split 1 was discarded. The rest was divided into 725 small bottles, each of them containing 1g reagent, from upper part (position 1) to lower part (position 725) in order.Isotopic ratios of JNdi-1 and LaJolla-Nd were determined by cyclic measurement on 12 mass spectrometers in 11 institutes using specific proce … More dures, except for the using of normalized value, <@D1143@>D1Nd/<@D1144@>D1Nd=0.7219.18 positions of JNdi-l were measured twice to twelve times, respectively. The values of jNdi-1 and LaJolla-Nd by cyclic measurement are defined as A and B,respectively, and F (Factor) vaoues are calculated from the two values, F<@D2n@>D2=2A<@D2n@>D2/(B<@D2n@>D2+B<@D2n+1@>D2). F values of several positions measured by the same instrument and the same procedure in one institute are consistent in the range of their standard deviation (2sigmam). Therefore, the isotopic composition of the reagent in the 1kg bottle is considered to be homogenous. This allows to calculate an average of F values of all 18 positions, that is 1.000503(]SY.+-。[)1 (1sigmam). The isotopic ratio of JNdi-1 which corresponds to 0.511857 of LaJolla-Nd is 0.512114(]SY.+-。[)7. Moreover, to consider the role of standard for variation of <@D1142@>D1Nd produced by decay of <@D1146@>D1Sm, that is the extinct nuclide, <@D1142@>D1Nd/<@D1144@>D1Nd ratios of JNdi-1 were also checked. From the results of the 104 data, it is found that the average of F values is 1.000006(]SY.+-。[)3 (1sigmam). This indicates that the values of JNdi-1 and LaJolla-Nd do not have a significant difference. Geological Survey of Japan has started to distribute the new isotopic standard regent (JNdi-1). Less

钕同位素标准要求杂质含量低。此外，（1）它应该具有高的^<143>Nd/^<144>Nd比，因为在日本通常研究的岛弧样品中具有高的比率;（2）应该具有低的稀土杂质，因为^ Ce和^ Sm减少了同量异位素干扰<142><144>。本文对SPEC、JMC、CERAC、MERCK、ShinEtsu和Mitsuwa等六家化学公司生产的高纯氧化钕进行了同位素比和稀土杂质的测定。优选ShinEtsu公司的试剂。从ShinEtsu公司购买两瓶1 kg氧化钕试剂（来自同一批次），并将其定义为分装1和分装2。丢弃了分离1的上部。其余样品按从上（1位）到下（725位）的顺序分装于725个小瓶中，每瓶1g试剂，在11个研究所的12台质谱仪上，采用特定的方法，循环测定JNdi-1和LaJolla-Nd同位素比值。 ...更多信息 除采用归一化值外，其余均采用&lt;@D1143@&gt; D_1 Nd/&lt;@D1144@&gt; D_1 Nd = 0.7219。通过循环测量的jNd 1 -1和LaJolla-Nd的值分别定义为A和B，并且F（因子）值由两个值计算，F&lt;@D2n@&gt;D2=2A&lt;@D2n@&gt;D2/（B&lt;@D2n@&gt;D2+B&lt;@D2n+1@&gt;D2）。同一个研究所用同一仪器、同一程序测定的几个位置的F值在其标准差范围内（2 σ m）是一致的。因此，认为1 kg瓶中试剂的同位素组成均匀。这允许计算所有18个位置的F值的平均值，即1.000503（± SY）。[)1（1 σ m）。LaJolla-Nd的0.511857对应的JNdi-1的同位素比值为0.512114（± SY）。[）7.此外，为了考虑由绝灭核素&lt;@D1146@&gt; D1 Sm衰变产生的&lt;@D1142@&gt; D1 Nd变化的标准作用，还检查了JNdi-1的&lt;@D1142@&gt; D1 Nd/&lt;@D1144@&gt; D1 Nd比值。从104个数据的结果中，发现F值的平均值为1.000006（± SY）。[)3（1 σ m）。这表明JNdi-1和LaJolla-Nd的值没有显著差异。日本地质调查局已开始分发新的同位素标准试剂（JNdi-1）。少

项目成果

C.Dragusanu, T.Tanaka and H.Iwamori: "Metamorphosed Precambrian mafic rocks from the South Carpathians : island arc remnants? A geochemical characterization of amphibolites from the Fagaras Mountains, Romania." Schweizerische Mineralogische und Petrograph

C.Dragusanu、T.Tanaka 和 H.Iwamori：“来自南喀尔巴阡山脉的变质前寒武纪镁铁质岩石：岛弧遗迹？罗马尼亚法加拉斯山脉角闪岩的地球化学特征。”

T.Nakano and Y.Ishikawa: "Chemical zoning of pegmatite garnets from the Ishikawa and Yamanoo areas, northeastern Japan." Geochemical Journal. 31. 105-118 (1997)

T.Nakano 和 Y.Ishikawa：“日本东北部石川和山尾地区伟晶岩石榴石的化学分区。”

C.Dragusanu and T.Tanaka: "The age and the origin of amphibolites from the South Carpathians : Implications for the pre-Alpine basement." The Journal of Geology. (to be accepted).

C.Dragusanu 和 T.Tanaka：“南喀尔巴阡山脉角闪岩的年龄和起源：对阿尔卑斯山前基底的影响。”

C. Dragusanu: "Metarmorphosed Precambrian mafic rocks from the South,Carpathians : island arc remnants ? A geochemical characterization of amphibolites from the Fagaras Mountains,Romania." Schweizerische Mineralogische und petrographische Mitteilungen. 77

C. Dragusanu：“来自喀尔巴阡山脉南部的变质前寒武纪镁铁质岩石：岛弧遗迹？罗马尼亚法加拉斯山脉角闪岩的地球化学特征。”

Y.Asahara: "^<87>Sr/^<86>Sr variation in north Pacific sediments : Arecord of the Milankovitch Cycle in the past 3 million years." Earth and Planetary Science Letters. (発表予定).

Y.Asahara：“北太平洋沉积物中的^<87>Sr/^<86>Sr变化：过去300万年的米兰科维奇循环记录。地球与行星科学快报”。