{"title":"低浓度氧化钕的高精度多收集器同位素分析","authors":"M.F. Thirlwall","doi":"10.1016/0168-9622(91)90036-V","DOIUrl":null,"url":null,"abstract":"<div><p>30 ng Nd samples loaded with silica gel and phosphoric acid on single rhenium filaments reproducibly provide <sup>144</sup>NdO<sup>+</sup> ion beams of ∼ 1.5-2 · 10<sup>−11</sup> A for several hours, without need of a poor source vacuum, or need to introduce oxygen into the mass spectrometer source. The loading technique discriminates strongly against CeO<sup>+</sup>, and accurate normalization for mass fractionation to <span><math><msup><mi></mi><mn>142</mn></msup><mtext>Nd</mtext><msup><mi></mi><mn>144</mn></msup><mtext>Nd</mtext></math></span> is possible. A 5-collector procedure for analysis and interference correction (<sup>18</sup>O, <sup>17</sup>O overlaps, CeO<sup>+</sup>, PrO<sup>+</sup>, SmO<sup>+</sup> ) is described which permits analysis of 30 ng Nd loads to internal precision of ±0.000005 (2se) in ∼2.5 hr. 17 loads (each 30 ng) of the laboratory Nd standard (analysed March–June 1990) yielded external precision of ±0.000007 (2sd) on <span><math><msup><mi></mi><mn>143</mn></msup><mtext>Nd</mtext><msup><mi></mi><mn>144</mn></msup><mtext>Nd</mtext></math></span>, and <span><math><msup><mi></mi><mn>143</mn></msup><mtext>Nd</mtext><msup><mi></mi><mn>144</mn></msup><mtext>Nd</mtext></math></span> and <span><math><msup><mi></mi><mn>145</mn></msup><mtext>Nd</mtext><msup><mi></mi><mn>144</mn></msup><mtext>Nd</mtext></math></span> values within 2se of the value determined on 500 ng Nd<sup>+</sup> runs, and a further 17, analysed October 1990–April 1991, give identical results within error. Eight sample analyses also agree within 2se between Nd<sup>+</sup> and NdO+ analyses, the latter being loaded from rinses of the disposable pipette tips used to load the Nd<sup>+</sup> runs.</p></div>","PeriodicalId":100231,"journal":{"name":"Chemical Geology: Isotope Geoscience section","volume":"94 1","pages":"Pages 13-22"},"PeriodicalIF":0.0000,"publicationDate":"1991-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0168-9622(91)90036-V","citationCount":"23","resultStr":"{\"title\":\"High-precision multicollector isotopic analysis of low levels of Nd as oxide\",\"authors\":\"M.F. Thirlwall\",\"doi\":\"10.1016/0168-9622(91)90036-V\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><p>30 ng Nd samples loaded with silica gel and phosphoric acid on single rhenium filaments reproducibly provide <sup>144</sup>NdO<sup>+</sup> ion beams of ∼ 1.5-2 · 10<sup>−11</sup> A for several hours, without need of a poor source vacuum, or need to introduce oxygen into the mass spectrometer source. The loading technique discriminates strongly against CeO<sup>+</sup>, and accurate normalization for mass fractionation to <span><math><msup><mi></mi><mn>142</mn></msup><mtext>Nd</mtext><msup><mi></mi><mn>144</mn></msup><mtext>Nd</mtext></math></span> is possible. A 5-collector procedure for analysis and interference correction (<sup>18</sup>O, <sup>17</sup>O overlaps, CeO<sup>+</sup>, PrO<sup>+</sup>, SmO<sup>+</sup> ) is described which permits analysis of 30 ng Nd loads to internal precision of ±0.000005 (2se) in ∼2.5 hr. 17 loads (each 30 ng) of the laboratory Nd standard (analysed March–June 1990) yielded external precision of ±0.000007 (2sd) on <span><math><msup><mi></mi><mn>143</mn></msup><mtext>Nd</mtext><msup><mi></mi><mn>144</mn></msup><mtext>Nd</mtext></math></span>, and <span><math><msup><mi></mi><mn>143</mn></msup><mtext>Nd</mtext><msup><mi></mi><mn>144</mn></msup><mtext>Nd</mtext></math></span> and <span><math><msup><mi></mi><mn>145</mn></msup><mtext>Nd</mtext><msup><mi></mi><mn>144</mn></msup><mtext>Nd</mtext></math></span> values within 2se of the value determined on 500 ng Nd<sup>+</sup> runs, and a further 17, analysed October 1990–April 1991, give identical results within error. Eight sample analyses also agree within 2se between Nd<sup>+</sup> and NdO+ analyses, the latter being loaded from rinses of the disposable pipette tips used to load the Nd<sup>+</sup> runs.</p></div>\",\"PeriodicalId\":100231,\"journal\":{\"name\":\"Chemical Geology: Isotope Geoscience section\",\"volume\":\"94 1\",\"pages\":\"Pages 13-22\"},\"PeriodicalIF\":0.0000,\"publicationDate\":\"1991-11-01\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"https://sci-hub-pdf.com/10.1016/0168-9622(91)90036-V\",\"citationCount\":\"23\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Chemical Geology: Isotope Geoscience section\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/016896229190036V\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"\",\"JCRName\":\"\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Chemical Geology: Isotope Geoscience section","FirstCategoryId":"1085","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/016896229190036V","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 23
摘要
在单铼丝上负载硅胶和磷酸的30 ng Nd样品可重复地提供约1.5-2·10−11 A的144NdO+离子束数小时,而不需要差源真空,也不需要在质谱仪源中引入氧气。加载技术对CeO+有很强的鉴别能力,可以将质量分馏精确归一化为142Nd144Nd。描述了用于分析和干扰校正(18O, 17O重叠,CeO+, PrO+, SmO+)的5收集器程序,该程序允许在~ 2.5小时内分析30 ng Nd负载,内部精度为±0.000005 (2se)。实验室Nd标准的17个负载(每个30 ng)(1990年3月至6月分析)在143Nd144Nd上的外部精度为±0.000007 (2sd), 143Nd144Nd和145Nd144Nd值在500 ng Nd+运行中确定的值的2se内,另外17个负载(1990年10月至1991年4月分析)在误差范围内给出相同的结果。8个样品分析也在2se内同意Nd+和NdO+分析,后者是从用于加载Nd+运行的一次性移液管尖端的冲洗中加载的。
High-precision multicollector isotopic analysis of low levels of Nd as oxide
30 ng Nd samples loaded with silica gel and phosphoric acid on single rhenium filaments reproducibly provide 144NdO+ ion beams of ∼ 1.5-2 · 10−11 A for several hours, without need of a poor source vacuum, or need to introduce oxygen into the mass spectrometer source. The loading technique discriminates strongly against CeO+, and accurate normalization for mass fractionation to is possible. A 5-collector procedure for analysis and interference correction (18O, 17O overlaps, CeO+, PrO+, SmO+ ) is described which permits analysis of 30 ng Nd loads to internal precision of ±0.000005 (2se) in ∼2.5 hr. 17 loads (each 30 ng) of the laboratory Nd standard (analysed March–June 1990) yielded external precision of ±0.000007 (2sd) on , and and values within 2se of the value determined on 500 ng Nd+ runs, and a further 17, analysed October 1990–April 1991, give identical results within error. Eight sample analyses also agree within 2se between Nd+ and NdO+ analyses, the latter being loaded from rinses of the disposable pipette tips used to load the Nd+ runs.