利用锶特效树脂分离富集岩石样品中的锶及测定~(87)Sr/~(86)Sr

本研究以Sr-Spec树脂作为分离锶的特效树脂,以HNO3为淋洗液,通过改变HNO3的浓度,将地质岩石样品中的锶分离富集.实验结果表明,Sr与基质元素和Rb能很好地分离.利用Sr-Spec树脂分离国际标准物质SRM607、日本岩石标样JA-2、JB-2、JF-2和国家标准物质GBW04111后, 测得同位素比值87Sr/86Sr结果及误差(2σ)分别为1.200660±22, 0.706350±17, 0.703640±16, 0.709692±22和0.700008±23.相对于常规的阳离子树脂分离方法,此方法所用淋洗试剂量少,分离流程短,可以降低实验空白并提高工作效率.因此,Sr-Spec树脂分离法是快速分离富集不同岩性地质样品的Sr并测定87Sr/86Sr的有效方法.     

电感耦合等离子体质谱法测定水泥样品中的铅同位素比值

研究和讨论了用电感耦合等离子体质谱仪(ICP—MS)测定铅的同位素比值测定时，影响测试结果的准确度和精密度的主要因素及其优化过程。在优化后的仪器分析条件下，测定5μg/L的NIST SRM981自然丰度铅同位素标准溶液的各对铅同位素比值，获得的^207Pb／^206Pb分析精度可优于0．1％。在该条件下测定了14个不同的水泥粉样品中的铅同位素比值，结果显示：铅的同位素比值分析技术可以用来示踪环境监测样品的铅污染源。     

多接收电感耦合等离子体质谱(MC-ICP-MS)法测定土壤的铁同位素组成

随着分析技术的发展,铁（Fe）同位素（δ56/54Fe）在土壤科学中得到了广泛的应用,可以用来研究铁在土壤圈中的迁移、转化等过程。为了确保不同类型样品中的铁同位素测量的准确性,需要标定一系列标准物质的铁同位素组成。但是目前对于土壤标准物质铁同位素数据的报道几乎没有,这阻碍了不同实验室间铁同位素数据质量进行对比。为了对不同实验室间的铁同位素数据进行比较,需要对土壤标样的铁同位素进行标定。在本研究中,我们使用硝酸-氢氟酸-高氯酸混酸对土壤样品中的硅酸盐和有机质进行消解,利用阴离子交换树脂（AG1-X8,0.038-0.074 mm）对土壤样品中的铁与基质元素进行了分离。为了获得可靠的纯化流程,我们检验了不同浓度的盐酸对基质的淋洗效果。结果表明,当盐酸浓度从4.0 mol/L变化到7.0 mol/L时,基质元素都能有效地被分离干净。最后我们采用5.0 mol/L的盐酸将基质元素从阴离子树脂中淋洗出来,然后利用0.3 mol/L的盐酸将铁元素收集起来。铁同位素组成利用多接收电感耦合等离子体质谱仪进行测定。通过对实验室标准铁溶液（ISS-Fe和USTC-Fe）的长期的监测,本分析方法δ56/54Fe的外精度好于±0.05‰（2SD）。我们分析了两个玄武岩标样（BCR-2和BHVO-2）的铁同位素组成,其δ56/54Fe值分别为0.08±0.05‰和0.09±0.05‰,均与文献值在误差范围内是一致的。此外,我们测量了六个土壤标样（SRM2709,SRM2709a,SRM2710a,SRM2711,SRM2711a和GBW07453）的铁同位素组成,其δ56/54Fe值分别为0.05±0.01‰,0.07±0.02‰,-0.11±0.02‰,0.15±0.03‰,0.14±0.03‰和0.10±0.01‰。该研究为土壤铁同位素研究提供了有用的数据库。     

AG50W-x8树脂分离去除钡的多原子离子对电感耦合等离子体质谱法测定稀土元素的质谱干扰

采用AG50W－x8阳离子交换树脂,以HNO3作为梯度淋洗剂,可有效地分离Ba和稀土元素,实验表明：以2mol/L HNO3淋洗时,99．5％的Ba被分离去除;以5mol/L HNO3淋洗时,稀土的回收率在96－110％之间。标准参考物质的分析结果显示测定值与标准值十分接近,表明AG50W－x8阳离子交换树脂分离可有效地去除Ba元素的多原子离子（BaO^ ,BaOH^ )对ICP－MS法测定稀土元素测定的质谱干扰,该方法准确,可靠。同时,为准确测定Eu提供了一条新的途径。     

绝对质谱法测量钐同位素丰度

使用高浓缩同位素的^152Sm和^154Sm配制不同丰度的Sm基准溶液,对多接收电感耦合等离子体质谱（MC-ICPMS）的系统偏差进行校准,求出^154Sm／^152Sm的平均校准系数。采用指数函数式推算出其它同位素比的校准系数。对天然样品的测量结果进行校正,并与表面热电离质谱的测量结果进行了比较,主同位素对的丰度比误差小于0．03％。实验结果表明,MC-ICPMS测量的影响因素多,系统偏差较大,但是通过校正可以获得与表面热电离质谱一致的测量结果。通过实验,建立了MC-ICPMS的同位素丰度绝对测量方法。     

同位素稀释电感耦合等离子体质谱(ID-ICP-MS)测定植物与人发标准物质中的铅

建立了同位素稀释电感耦合等离子体质谱(ID-ICP-MS)测定铅的方法.考察和讨论了仪器参数对同位素比值测定的影响,优化了仪器的数据采样参数.利用内标Tl对质量歧视、系统漂移进行了校正.讨论了同位素浓缩剂加入量对最终浓度测定值的不确定度的影响.将该方法应用于植物标准物质和人发标准物质的测定,结果令人满意.     

同位素稀释电感耦合等离子体质谱测定环境和生物样品中的镉

应用同位素稀释电感耦合等离子体质谱（ID—ICP—MS）对环境和生物样品茶叶、湖沉积物和人发标准物质中的镉进行测定研究。对电感耦合等离子体质谱（ICP—MS）的工作条件和参数进行了最优化。讨论了多原子离子和同量异位素对镉同位素比值的影响,通过天然镉标准溶液对质量歧视进行了校正,并优化同位素稀释剂的加入量。将该方法应用于茶叶、人发和沉积物标准物质的测定。     

应用多接收器电感耦合等离子体质谱法测定海洋碳酸盐中稳定铅同位素组成

研究了多接收器电感耦合等离子体质谱仪(MC-ICP MS)测定铅同位素比值时,影响测试结果准确度和精密度的主要因素及其优化过程。在优化条件下,10 h内连续30次测定4 ng/mL NIST SRM 981同位素标准溶液铅同位素比值,获得208Pb/206Pb、207Pb/206Pb和206Pb/204Pb相对标准偏差(RSDs)分别为0.005%、0.004%和0.054%。长期监测208Pb/206Pb、207Pb/206Pb和206Pb/204Pb,标准偏差(2SDs)分别为0.000 06、0.000 05和0.006 7。采用NEPTUNE MC-ICP MS法测定了低铅海洋碳酸盐样品中稳定铅的同位素比值,并对南海橙黄滨珊瑚(Porites lutea)和库氏砗磲(Tridacna gigas)进行了分析,得到全流程空白为8～10 pg,重复样误差优于0.1%。经0.50 mol/L HNO3洗脱之后,得到海南珊瑚样品中208Pb/206Pb、207Pb/206Pb的比值分别为2.086 2±0.001 5、0.849 90±0.001 47(n=16);海南砗磲样品中208Pb/206Pb、207Pb/206Pb的比值分别为2.116 9±0.004 2、0.864 81±0.001 62(n=9)。进一步考察了南海海洋碳酸盐中204Pb的同位素比值。分析结果表明,南海海洋碳酸盐中稳定铅同位素比值与中国气溶胶、珠江三角洲大气沉降、黄土及南海海底玄武岩等具有很好的相关性。方法适用于复杂基体高钙低铅的海洋碳酸盐样品中铅同位素比值的分析。     

多接收电感耦合等离子体质谱法高精密度测定汞同位素组成

采用多接收等离子体质谱(MC-ICP-MS)方法高精度测定了Hg同位素组成.本方法借助在线进样系统,最大程度上克服了同位素干扰和基体效应;采用同位素内标法和样品-标准交叉法以消除仪器自身的质量分馏;通过实验条件(如测定时间、进样量等)的优化,方法的内精度显著提高.研究表明: 为保证汞同位素组成的高精度测定,汞最低进样浓度为2 μg/L时,内精度＜0.02‰(RSD).运用本方法对汞标准NIST SRM 3133和UM-Almadén实验室内标样长达7个月的测定,结果表明,本方法外精度＜0.06‰(2SD).此外,对一系列环境样品的同位素组成进行了测定,样品的外精度＜0.10‰(2SD).测定样品δ202Hg变化范围为-3.48‰～0 63‰, 幅度达4.11‰.     

HAc溶解碳酸盐岩测定87Sr/86Sr值实验方法研究

传统的碳酸盐岩的sr同位素比值测定因为采用HCl溶样,往往导致非碳酸盐组分的溶解,引起测定值偏高,采用HAc溶样可以防止样品中非碳酸盐组分的溶解,同时也避免过多的杂质离子进入溶解液,从而使^87Sr／^86Sr测定值趋于准确和可靠;通过2.5mol/L HAc溶解碳酸盐矿样和4.0mol/L HCl溶解残渣样的最后质谱测定的^87Sr／^86Sr值比较,证实碳酸盐岩中非碳酸盐组分的^87Sr／^86Sr值较碳酸盐组分高。     

The determination and application of 87Sr/86Sr ratio in verifying geographical origin of wheat

As ⁸⁷Sr/⁸⁶Sr ratio plays a significant role in authenticating the geographical origin of foodstuff, it is important to identify where the ⁸⁷Sr/⁸⁶Sr signature in food comes from, and the methods of ⁸⁷Sr/⁸⁶Sr ratio analysis in food and environmental samples. Wheat with three genotypes, soil and groundwater samples were collected from three regions of China during harvest time of 2014. The ⁸⁷Sr/⁸⁶Sr ratios in the samples were determined by thermal ionization mass spectrometer in order to investigate the possible source of ⁸⁷Sr/⁸⁶Sr in wheat, and the concentrations of Rb and Sr in wheat and soils were also detected by inductively coupled plasma mass spectrometry and combined with ⁸⁷Sr/⁸⁶Sr ratio in order to trace the geographical origin of wheat. The ⁸⁷Sr/⁸⁶Sr ratio, the contents Rb and Sr, and Rb/Sr ratio of wheat and soil samples showed significant differences among three regions. The ⁸⁷Sr/⁸⁶Sr ratios and the concentrations of Rb and Sr in soils were higher than those in corresponding wheat. The ⁸⁷Sr/⁸⁶Sr ratio in wheat was identical to that corresponding soil NH₄NO₃ extracts (labile fraction of soil) and groundwater. Wheat uptake more Rb than Sr. 3D distribution of ⁸⁷Sr/⁸⁶Sr, Rb and Sr could identify wheat samples from different regions clearly. The ⁸⁷Sr/⁸⁶Sr ratio of wheat reflects the ⁸⁷Sr/⁸⁶Sr ratio of the associated environment including soil and groundwater. It is expected that the use the parameters of ⁸⁷Sr/⁸⁶Sr ratio, the contents of Rb and Sr will allow to trace geographical origin of wheat. Copyright © 2017 John Wiley & Sons, Ltd.     

Specificity and Origin of the Stability of the Sr Isotopic Ratio in Champagne Wines

The ⁸⁷Sr/⁸⁶Sr ratio of 39 Champagnes from six different brands, originating from the whole “Appellation d’Origine Contrôlée” (AOC) Champagne was analyzed to establish a possible relation with the geographical origin. Musts (i.e., grape juice) and base wines were also analyzed to study the evolution of the Sr isotopic ratio during the elaboration process of sparkling wine. The results demonstrate that there is a very homogeneous Sr isotopic ratio (⁸⁷Sr/⁸⁶Sr = 0.70812, n = 37) and a narrow span of variability (2σ = 0.00007, n = 37). Moreover, the Sr concentrations in Champagnes have also low variability, which can be in part explained by the homogeneity of the bedrock in the AOC Champagne. Measurements of the ⁸⁷Sr/⁸⁶Sr ratio from musts and base wines show that blending during Champagne production plays a major role in the limited variability observed. Further, the ⁸⁷Sr/⁸⁶Sr of the musts were closely linked to the ⁸⁷Sr/⁸⁶Sr ratio of the vineyard soil. It appears that the ⁸⁷Sr/⁸⁶Sr of the product does not change during the elaboration process, but its variability decreases throughout the process due to blending. Both the homogeneity of the soil composition in the Champagne AOC and the blending process during the wine making process with several blending steps at different stages account for the unique and stable Sr isotopic signature of the Champagne wines.     

葡萄酒中二氧化硫含量的快速测定

采用凯氏定氮仪对葡萄酒样品进行蒸馏,然后用自动电位滴定仪测定葡萄酒中二氧化硫的含量。考察了凯氏定氮仪与玻璃蒸馏仪、自动电位滴定仪与玻璃滴定管、搅拌速度及滴定速度对测定结果的影响。测定结果显示,凯氏定氮仪-自动电位滴定仪测定结果与GB/T5009.34-2003规定的采用玻璃仪器方法测定结果无显著性差异。该方法的加标回收率为88.8%~103.6%。     

High-precision direct determination of the Sr/Sr isotope ratio of bottled Sr-rich natural mineral drinking water using multiple collector inductively coupled plasma mass spectrometry

We describe a precise and accurate method for the direct determination of the ⁸⁷Sr/⁸⁶Sr isotope ratio of bottled Sr-rich natural mineral drinking water using multiple collector inductively coupled plasma mass spectrometry (MC-ICP-MS). The method is validated by the comparative analysis of the same water with and without cation-exchange resin purification. The work indicates that isobarically interfering elements can be corrected for when ⁸⁷Rb/⁸⁶Sr < 0.05 (Rb/Sr < 0.015), and that the matrix elements (Ca, Mg, K and Na) have no significant effect on the accuracy of the Sr isotope data. The method is simple, rapid, eliminates sample preparation time, and avoids potential contamination during complicated sample-preparation procedures. Therefore, the high sample throughput inherent to the MC-ICP-MS can be fully exploited.     

乙酰丙酮吸光光度法测定白酒中甲醇含量

乙酰丙酮法测定白酒中甲醇是一种新的测试方法。白酒样品用高锰酸钾氧化后，加草酸除去过量的氧化剂，在pH3～4范围内，加入乙酰丙酮溶液，在沸水浴中显色，于418nm波长处测量其吸光度。方法步骤简单，具有较高的灵敏度和较高的重现性。     

微波等离子体原子发射光谱法测定葡萄酒中的7种微量元素

利用510型微波等离子炬原子发射光谱仪对葡萄酒中铅、镁、铝、铜、锰、铁和锌7种金属元素进行了测定,考察了载气流量、工作气流量、酸度对7种金属元素发射强度的影响.在选定的最佳测试条件下,利用工作曲线法测定了红葡萄酒样品中的金属离子含量.该方法测定结果的相对标准偏差为1. 08%～5. 55%(n=4),加标回收率为93. 6%～105. 3%.     

87Sr/86Sr measurements on marine sediments by inductively coupled plasma-mass spectrometry

The application of inductively coupled plasma-mass spectrometry (ICP-MS) is documented for the study of the strontium isotopic composition (⁸⁷Sr/⁸⁶Sr) in geological samples, i.e. in the marine lithic fraction of core sediments. Methods for the determination of the isotopic composition, its accuracy and precision are reported. The results obtained simultaneously on 11 samples by both ICP-MS and thermal ionization mass spectrometry (TIMS) reveal a very good correlation (r² = 0.955). Received: 24 February 1997 / Revised: 26 May 1997 / Accepted: 30 May 1997     

87Sr/86Sr measurements on marine sediments by inductively coupled plasma-mass spectrometry

The application of inductively coupled plasma-mass spectrometry (ICP-MS) is documented for the study of the strontium isotopic composition (⁸⁷Sr/⁸⁶Sr) in geological samples, i.e. in the marine lithic fraction of core sediments. Methods for the determination of the isotopic composition, its accuracy and precision are reported. The results obtained simultaneously on 11 samples by both ICP-MS and thermal ionization mass spectrometry (TIMS) reveal a very good correlation (r² = 0.955). Received: 24 February 1997 / Revised: 26 May 1997 / Accepted: 30 May 1997     

核磁氢谱法测定葡萄酒中的乙醇

以 3 三甲基甲硅烷基 2 ,2 ,3,3 四氘代丙酸钠 (TSP)为内标物 ,利用核磁氢谱法测定葡萄酒中的乙醇。用核磁氢谱法测得的葡萄酒国际比对样品中乙醇的含量为 (81.11± 0 .2 1)mg/g ,与气相色谱法对葡萄酒中乙醇的定值结果一致。