x射线荧光光谱无标半定量分析稀土元素方法的改进

在Philips公司提供的x射线荧光光谱基本参数法半定量分析的SemIQ软件基础上引入重稀土元素的分析，用光谱纯的稀土氧化物与四硼酸锂熔融制备标样，重新建立一套半定量分析方法，使原软件不能分析的Dy、Ho、Er元素也可进行半定量分析，并提高了Eu、Gd、Tb、Tm、Yb、Lu元素分析的准确度。应用该方法进行了大量稀土样品的半定量分析，并与原软件方法对照，结果明显改善。     

X射线荧光光谱法直接测定地质样品中多种痕量元素

采用低压聚乙烯镶边垫底的粉末压饼法制样,Ｘ射线荧光光谱法直接测定了地质样品中痕量元素Ａｓ、Ｇａ、Ｓｃ、Ｌａ、Ｙ、Ｃｅ、Ｗ、Ｍｏ、Ｓｎ、Ｃｏ和Ｐｂ。讨论了背景校正、谱线重叠校正、基体效应校正和仪器漂移校正等问题。利用理论α系数代替经验系数,使方法具有较高的准确度和较低的检出限。所测１１个元素的检出限在（０．３０～２．０２）×１０－６水平,精度（ＲＳＤ,ｎ＝１１）在０．９５％～１３．０％。方法经国家一级标准物质分析验证,结果与标准值相符。     

地质样品痕量氯溴和硫的X射线荧光光谱法测定

报道了粉末压样－X射线荧光光谱法测定地质样品中痕量Cl、Br、S的分析方法。采用水系沉积物、岩石和土壤等国家一级标准物质进行校准。实验表明，对于不同岩性样品中Br的分析，特别是当Br的含量低于2μg/g时，采用谱峰强度（未扣除背景）与背景强度的比进行校准所得到的结果，明显优于铑靶线的Compton散射线内标法，分析精度（RSD,n=6)为2.4%-15.3%，大多数优于10％；平均值的相对误差低于24％。对于Cl的分析，只需对Ca的影响加以校正即可得到非常好的结果；不同样品中Cl的分析精度（RSD，n=6)为2.1%-13.6%，大多数优于5％；平均值的相对误差不大于25％，多数优于10％。S的校准曲线的离散性较大，矿物学效应是影响S分析准确度的主要因素，其分析精度（RSD,n=6)为0.87%-5.6%，除个别样品外，平均值的相对误差优于36％。Cl和S均存在分析结果随测量时间（次数）的增加而增高的现象，必须在制样后立即测量。方法的检出限（μg/g)Br、Cl、S分别为0．43、5．8和2．2。     

X射线荧光光谱集成分析系统

选用了兼容性能好的３８６微机，在ＤＯＳ操作系统和Ｗｉｎｄｏｗｓ３．１环境下，研究开发了Ｘ射线荧光光谱集成分析系统（ＸＲＦＩＡＳ），全面更新了理学公司３０８０系列仪器的计算机硬件和软件。采用了当前最流行的多窗口，全屏幕友好界面，在西文ＤＯＳ操作系统下，显示汉字信息。有常规的（背景扣除，内标校正，谱重叠校正，基体校正）数据处理功能（多种校正模式）扩充了分析元素，内标元素、干扰元素的数量，新开发了共用背     

Routine Control of Accuracy in Silicate Rock Analysis by X-Ray Fluorescence Spectrometry

In this study, we used the modified Horwitz expression (H_c= 0.01c^0.8495, which gives the precision as a function of concentration) to evaluate and control the accuracy of results of silicate rock analysis obtained by X-ray fluorescence spectrometry. This expression is currently used by the organisers of the GeoPT international proficiency tests, to assign the precision limits of each analyte and subsequently to evaluate the data provided by laboratories whose main application is geochemistry. Results for major and trace elements, determined in glass disk and pressed pellets, respectively, were evaluated. Nine international silicate rock reference materials were analysed and results were compared to the recommended values plus and minus the limits given by the above expression. Those limits are easily attained for most major elements, but not for trace elements. Sample preparation and sub-sampling contributions to precision were evaluated by analysis of an in-house reference sample. In our results, precision does not follow the Horwitz expression relationship with concentration. It is known that the final accuracy in XRF analysis depends strongly on instrumental settings and on the uncertainties associated with the certified or recommended values of the reference materials used to calibrate the spectrometer, but our results indicate that the precision expression can be useful, especially to inspect and correct calibration curves and to check routine instrumental accuracy.     

X射线荧光光谱分析技术在过程分析中的应用

X射线荧光光谱(XRF)分析作为过程分析化学中一门富有成效的分析技术,在现场分析、流程控制中发挥了积极的作用。文章评述了XRF分析在冶金、地质、采矿、选矿等方面的应用概况以及在国内此领域的发展。     

单纯形调优技术在XRFA法中的应用

XRFA法在元素定性、定量分析中,当谱带严重重叠或干扰元素含量远大于待测元素含量时,可采取多种方法消除干扰。本文采用单纯形调优法分离技术测量未知元素的含量,结果较为满意。     

联袂应用X 荧光与幅频激电法勘查川西某铜矿

在川西某铜矿区应用X荧光与幅频激电测量方法,证实了地质推测的隐伏含矿断裂的存在,并确定了该断裂的延伸方向和具体位置,取得了良好的地质找矿效果,为矿区进一步找矿及山地工い程的布置提供了科学依据.实践表明,在矿区采用X荧光扫面捕获Cu异常,以幅频激电拟断面测量解剖Cu异常,在技术组合上是科学的,对矿区勘查实践是实用和有效的.此次工作的结果充分体现了联袂应用X荧光与幅频激电现场测量的优越性和有效性.     

Flood response to rainfall variability during the last 2000 years inferred from the Taravilla Lake record (Central Iberian Range, Spain)

A sedimentological, geochemical and palynological study of the Taravilla Lake sequence (Central Iberian Range, NE Spain) provides a detailed record of allochthonous terrigenous layers that intercalate within the lacustrine sediments over the last 2000 years. These terrigenous layers are interpreted as the result of extreme hydrological events that caused higher clastic input to the basin. Anthropogenic influence caused by fires or deforestation is rejected as the main factor generating these layers because human impact, inferred from the pollen reconstruction, was minimal when the terrigenous layers reached their greatest frequency. The reconstructed occurrence of these events in the Taravilla Lake record is coherent with the paleoflood history of the Tagus River, characterized by a notable increase of extreme events at the beginning of the Little Ice Age. The Taravilla record suggests a relationship between the occurrence of extreme hydrological events, solar variability, and the North Atlantic Oscillation for the NE Iberian Peninsula.     

MIS 3以来浙江温瑞平原YQ0902孔古环境与古气候变化记录*

YQ0902孔位于浙江南部瓯江三角洲南侧温瑞平原上。沉积相、粒度分析以及AMS ¹4C测年数据表明,硬土层之下为海洋氧同位素3阶段(MIS 3）形成的潟湖相沉积,据此推测MIS 3高海平面至少达到现今海平面之下30m左右(未经构造升降和沉积物压实作用等影响的校正,下同）。硬土层的成土过程发生于MIS 2,其母质部分为MIS 3的潟湖沉积,部分为河漫滩沉积。硬土层之上是一套形成于全新世的海侵—海退旋回,与长江三角洲南翼前缘的沉积相组合类似。研究钻孔初始海泛面约形成于9 cal ka BP,推算当时的海平面约低于现今海平面25 m。中全新世最大海侵前后,东亚季风较强,通过径流或沿岸流输入本区的沉积物较充足,沉积速率较大。随着海平面相对稳定或略有下降,东亚季风减弱,可容空间减小,中晚全新世(5～2 cal ka BP）沉积速率较低。高分辨率的XRF岩心扫描获得的元素相对含量是古环境与古气候研究的重要指标,其中Cl/Ti、Fe/Ti值可分别作为海相性(与海洋联通程度）与东亚季风强弱的替代指标。