微波溶样ICP—MS直接测定茶叶中15种前量稀土元素

本文报道用ＨＮＯ３－Ｈ２Ｏ２微波溶样，不经分离富集，用标准加入ＩＣＰ－ＭＳ法，直接测定茶叶中１５种痕量稀土元素，对微波溶样和等离子体质谱测定条件进行了优化选择，在最佳实验条件下，用本法测定了国家一级茶叶标准ＧＢＷ０７６０５中的单一稀土元素，测得值与标准值很好吻合。     

微波溶样－ICP－AES法测定人发标准物质中15种超痕量稀土元素的研究

本文采用微波溶样，不经分离富集，直接用标准加入ＩＣＰ－ＭＳ法，测定人发标准物质中１５种超痕量稀土元素。选择了最佳样品预处理条件和测定的最佳仪器参数。检出限为０．００７～０．０２６ｎｇ／ｍＬ。用国家一级土壤标准物质（ＧＢＷ０７４０１和ＧＢＷ０７４０３）作为质控样，１５种痕量稀土元素的测得值与标准值很好地吻合，相对标准偏差（ＲＳＤ）为１．２％～５．４％。国家一级人发标准物质（ＧＢＷ０７６０１）中稀土元素的标准值仅有Ｌａ，Ｃｅ和Ｙ，本法测得值均落在标准值的置信区间内。其余１２个超痕量稀土元素本法也取得了较为满意的结果。     

微波溶样-分光光度法测定螺旋藻中的碘

用微波溶样－分光光度法测定螺旋藻中的碘,溶样快速,简单,安全。ＲＳＤ２．４％￣４．１％,回收率９７．１％￣１０３．３％。     

微波溶样—ICP—AES法测定人发标准物质中15种超痕量稀土元素的研究

本文采用微波溶样，不经分离富集，直接用标准加入ＩＣＰ－ＭＳ法，测定人发标准物质１５种超痕量稀土。选择了最佳样品预处理条件和测定的最佳仪器参数。     

离子色谱法测定α—氧化铝中微量硫酸根的研究

本建立了用氢氧化钠溶样，离子色谱测定α－Ａｌ２Ｏ３中微量硫酸根的方法。在ＤｉｏｎｅｘＡＳ４Ａ分离柱上，用１．８×１０＾－＾３ｍｏｌ／ＬＡａ２ＣＯ３作流动相进行洗脱，电导检测器检测，分析方法简便，快速，硫酸根的检测限为１．０×１０＾－＾２μｇ／ｍｌ，相对标准偏差为２．６７％，回收率为９７．５％，扩展了离子色谱法测定实际样品的范围。     

感耦等离子体质谱法（ICP—MS）测定高纯氧化镝中痕量稀土杂质

本文报道用２－乙基己基膦酸单酯萃淋树脂为固定相，ＨＣｌ为淋洗液的萃取色谱法研究了高纯Ｄｙ２Ｏ３中的痕量稀土杂质和Ｄｙ２Ｏ３基体的分离条件，并用ＩＣＰ－ＭＳ法测定了高纯Ｄｙ２Ｏ３中的１４个稀土杂质，稀土元素的测定限为０．００１－０．００５ＩＣＰ－ＭＳ法测定了高纯Ｄｙ２Ｏ３     

原子吸收法在有机分析中的应用（Ⅲ）：茶叶中茶多酚的测定

研究了间接测定茶叶中茶多酚的原子吸收，用甲基异丁酮和丁醇的混合溶剂萃取茶汤中的茶多酚，与氨基酸分离后，加入碱性Ｃｕ３（ＰＯ４）２悬浮液反萃取并同茶多酚作用，离心沉降未作用的Ｃｕ３（ＰＯ４）２后，用原子吸收法测定Ｃｕ，可求得茶多酚的含量，本法可消除茶叶共存氨基酸的干扰，测定结果同标准方法一致，回收率范围为９４％－１０４％，平均标准偏差为３．１％。     

动力学—两次标准加入法同时测定钼和钨

本文提出了动力学－两次标准加入法双组份同时测定的新方法，讨论了测定的基本原理；用停流ＦＩＡ光度法研究了钼和钨共同催化的Ｈ２Ｏ２－Ｉ＾－动力学反应体系，并建立了钼和钨同时测定的条件，用本法测定了钢样和模拟样品中的钼、钨含量，结果满意，钼和钨的回收率分别为９７％－１０２．６％和９８．２％－１０３％；相对标准偏差分别为２．８％－３．２％和２．１％－３．５％。     

微波条件下V2O5/TiO2低温选择氧化甲苯制苯甲酸

在微波辐射条件下，考察了甲苯选择氧化过程中催化剂床层温度、Ｏ２／甲苯比、原料气总空速、Ｖ２Ｏ５担载量和添加氧化物助剂等条件对Ｖ２Ｏ５／ＴｉＯ２催化剂活性的影响．结果表明，在微波作用下，当床层温度在２５０℃，Ｏ２／甲苯摩尔比６和原料气总空速１００００ｈ－１时，１％ＭｏＯ３－８％Ｖ２Ｏ５／ＴｉＯ２上的苯甲酸和苯甲醛的收率分别达到４１％和１４％．与传统加热的催化过程相比，苯甲酸和含氧化物的收率均有较大的提高．还初步探讨了微波对催化剂活性的影响．     

ICP-AES法同时测定石英砂中的痕量元素

采用微波溶样，并通过条件试验，建立了微波溶样ICP－AES法同时测定石英砂中13种痕量元素的分析方法并已应用于实际样品的分析，方法的相对标准偏差≤10％，加标回收率为90％－107％。     

电感耦合等离子体质谱测定中草药中痕量稀土元素的研究

本文报道了微波消解／ICP－MS测定中草药中痕量稀土元素的新方法。在优化实验条件下，方法的检出限为0.71-15.2pg/mL，相对标准偏差为0.80%-3.3%，加标回收率为87.4%-106%。该法具有操作简便、快速、灵敏度高、准确度好和多元素同时测定等优点。     

银菊珍珠胶囊中稀土元素的电感耦合等离子体质谱分析

建立了一种电感耦合等离子体质谱法测定银菊珍珠胶囊中稀土元素的方法。利用该方法分析了国家一级灌木枝叶标准物质（GBW 07603）和国际柑橘叶标准物质（NIST1572）中的稀土元素，结果与标准值一致。该方法已被用于分析银菊珍珠肢囊样品中的稀土元素。     

电感耦合等离子体质谱分析莲子芯茶中的稀土元素

建立了一种压力密闭消解电感耦合等离子体质谱法测定莲子芯茶中Y、La、Ce、Pr、Nd、Sm、Eu、Gd、Tb、Dy、Ho、Er、Tm、Yb、Lu等15种稀土元素的方法。用该方法分析国家标准物质中的稀土元素,分析结果与标准值一致,并用该方法对莲子芯茶实际样品进行了分析。     

茶叶中稀土元素的萃取分离-ICP-AES法测定

采用1-苯基-3-甲基-4-苯甲酰基-5-吡唑酮(PMBP)苯溶液萃取分离-ICP-AES法同时测定茶叶中15种稀土元素,消除了基体的干扰,并对样品前处理方法、萃取分离条件进行了考查.方法回收率为: 92.3%～112%,相对标准偏差＜2.5%.在最佳工作条件下,测定了茶叶标准物质(GBW07605)中稀土元素,结果与标准值吻合.     

Assessment of the ICP-MS method using the interlaboratory QA study of two Polish soil RMs

 Under an international collaborative certification programme, two new Polish soil reference materials, PL-1 (loess) and BPGM-1 (sandy loam soil), were analysed for 34 trace elements including all the rare earth elements using the acid decomposition method and inductively coupled plasma - mass spectrometry (ICP-MS). After the certification by the organisers, the analytical data obtained at our institute were compared with the certified data. 'Z-score' values calculated for individual trace elements helped in the assessment of the quality of the data. While the majority of the data obtained on ICP-MS was very precise and accurate, some of the data especially for elements such as Zr, Hf and Nb suffered from incomplete dissolution of the sample and spectroscopic interferences. For some trace elements, certified data are not available for comparison. These features together with the usefulness of interlaboratory collaborative programmes and ICP-MS for the certification of soil reference materials are discussed. Received: 6 August 1999 / Accepted: 28 February 2000     

冷焰ICP-MS法测定高纯稀土氧化物中铁和钙的研究

用冷焰技术对高纯稀土氧化物中Ｆｅ和Ｃａ的分析方法进行了研究。估算了测定范围和检出限,探讨了内标元素对基体影响的校正作用,测定了加标回收率,对半定量法（ＴＱ）和定量法（ＱＡ）的结果作了比较。表明冷焰条件下,痕量Ｆｅ的测定是可行的,但Ｃａ的测定结果仍不理想;ＱＡ法明显优于ＴＱ法。     

Carbon Nanofibers as Solid‐Phase Extraction Adsorbent for the Preconcentration of Trace Rare Earth Elements and Their Determination by Inductively Coupled Plasma Mass Spectrometry

Abstract

Systematic investigations were carried out into the sorption of rare earth elements (REEs) on carbon nonofibers (CNFs) by inductively coupled plasma mass spectrometry (ICP‐MS). The experimental parameters for preconcentration of REEs, such as pH, sample flow rate and volume, eluent concentration, and interfering ions on preconcentration of REEs have been examined in detail. The studied metal ions can be adsorbed quantitatively on CNFs in a pH range from 2.0 to 5.0, and then eluted completely with 0.5 mol l^?1 HNO₃. Based on the above facts, a novel method using a microcolumn packed with carbon nanofibers as an adsorption material was developed for the separation and preconcentration of REEs prior to their determination by ICP‐MS. The proposed method has been successfully applied to the determination of light (La), medium (Eu and Gd) and heavy (Yb) rare earth elements in real sample with the recovery more than 90%. In order to validate this method, two certified reference materials of tea leaves (GBW 07605) and mussel (GBW 08571) were analyzed, and the determined values are in good agreement with the certified values.     

Determination of trace rare earth elements by inductively coupled plasma atomic emission spectrometry after preconcentration with multiwalled carbon nanotubes

A new method has been developed for the determination of trace rare earth elements (REEs) in water samples based on preconcentration with a microcolumn packed with multiwalled carbon nanotubes (MWNTs) prior to their determination by inductively coupled plasma atomic emission spectrometry (ICP-AES). The optimum experimental parameters for preconcentration of REEs, such as pH of the sample, sample flow rate and volume, elution solution and interfering ions, have been investigated. The studied REEs ions can be quantitatively retained by MWNTs when the pH exceed 3.0, and then eluted completely with 1.0 mol L⁻¹ HNO₃. The detection limits of this method for REEs was between 3 and 57 ng L⁻¹, and the relative standard deviations (RSDs) for the determination of REEs at 10 ng mL⁻¹ level were found to be less than 6% when processing 100 mL sample solution. The method was validated using a certified reference material, and has been successfully applied for the determination of trace rare earth elements in lake water and synthetic seawater with satisfactory results.     

Determination of rare earth elements in soils and sediments by inductively coupled plasma atomic emission spectrometry after cation-exchange separation

The influence of matrix elements such as Ba, Ca, Fe, K, Na and Ti, on the inductively coupled plasma atomic emission spectrometry determination of the rare earth elements in soils and sediments is investigated and analytical lines with minimal interferences are chosen. The analysis of certified reference materials by two calibration methods (pure rare earth solutions and IAEA-Soil 5) and after cation-exchange proved that calibrations with IAEA-Soil 5 increase the number of accurately determined rare earth elements (REE), permitting the instrumental determination of Ce, Eu, La, Nd, Tb, Yb and Y in soils and some sediments. The cation-exchange procedure permits the determination of 12 REE with very good accuracy (below 10%) and detection limits varying between 0.05 (Eu, Tb, Yb) and 0.5 (Er) mg kg(-1).     

Distribution of trace elements in the marine sediments along the South China Sea,Malaysia

In order to complete having data base of elemental assessment of the east coast of Peninsular Malaysia marine sediments along the South China Sea coasts, trace elements are analyzed and their distribution in marine sediments is undertaken. The present study is done parallel with pervious study on elemental assessment of heavy metals, rare earth elements and actinides in the marine sediments of the east coast of Peninsular Malaysia. Thirty surface sediment samples were collected in this area, including regions of Kelantan, Terengganu, Pahang, Rompin and Johor Baharu. Multielemental analysis was carried out by instrumental neutron activation analysis and inductively coupled plasma atomic emission spectroscopy. In both cases methodology validation was performed by certified reference material analyses. For the surface elemental distributions the enrichment factor values, average I _geo and mC _d values indicate that the trace elements of the surface sediments are uncontaminated in all sampling stations that are consistent with previous studies results of heavy metals, rare earth elements and actinides.