X射线荧光光谱法测定地质样品中的硫和氟

采用粉末压片制样-X射线荧光光谱法研究地质样品中硫(S)和氟(F)元素的快速测定方法。通过分级过筛实验优化确定样品粒度,探讨样品粒度对测定结果的影响,并进行实际样品和标准物质验证。结果显示,样品粒度为85μm时,经实际样品和标准物质验证,测定结果与化学值和标准认定值相符,且相对标准偏差(RSD)均小于2%。方法具有准确度高、检出限好、测试范围宽、简便快速等优点,能确保样品分析结果的准确性,实现了地质样品中S和F的快速测定。     

X射线荧光光谱法测定锡矿石中锡

本文采用向样品中加入硼酸来降低基体效应,加入氧化镧来稳定样品总质量吸收系数,建立固体粉末压片制样-X射线荧光光谱法测定锡矿石中锡含量的方法。通过将标准物质按一定比例混合配制和选取部分自制标样来补充标准物质样品,以解决锡矿石标准物质样品缺乏的问题。实验优化了稀释比,确定了以最佳稀释比为m（矿物质样品）:m（硼酸）：m（氧化镧）=1.0:2.0:0.5。在最优的实验条件下,Sn的荧光强度（kcps）与Sn浓度CSn呈良好的线性关系,R2=0.9989。方法中锡元素的最低检出限为0.005 %,测定范围在0.015 %-4.47 %之间。样品的混合均匀性实验表明各元素测定结果的相对标准偏差（RSD,n=6）在1.0 %-2.64 %之间。对3个不同含量段的物质进行测定来验证方法的准确度和精密度,准确度分别为0.0082-0.0367,均小于0.04,精密度分别为0.39 %-1.18 %,均小于8.0 %,准确度和精密度均符合地质样品分析规范要求。测定值均在误差范围内,各组分测定结果的相对标准偏差（RSD,n=11）在1.20 %以下。粉末压片-X射线荧光光谱法测定锡矿石中锡含量具有分析范围广、分析时间短、重现性好、精度高且操作简单等特点。能应用于地质、环境、材料等领域。     

水质浊度标准物质的研制

介绍水质浊度国家二级标准物质的研制。参照国际标准ISO 7027中规定的方法,以硫酸肼和六次甲基四胺为原料,采用重量-容量法,根据样品的纯度值、称取的质量及溶液定容体积计算配制值作为标准值,采用高精度浊度仪进行量值核对。样品分装成90瓶后,使用高精度浊度仪进行均匀性和稳定性检验。从样品中随机抽取16瓶进行测定,对测定结果进行F检验,证明标准溶液的均匀性良好。对标准物质溶液进行稳定性检验,证明在1年有效期内稳定性良好。研制的水质浊度标准物质的浊度值为400 NTU,相对扩展不确定度为3%(k=2)。该标准物质符合国家二级标准物质的要求,能够用于水质监测质量控制。     

交流电弧发射光谱法测定地球化学样品中的高含量锡

建立了交流电弧发射光谱法测定化学样品中锡的方法。以氧化锌、氟化钠、硫粉为缓冲剂,改善元素蒸发行为;以锗为内标,样品与缓冲剂比例为1∶1。根据不同含量的锡选择不同级别灵敏线进行分析,采取内标法,建立浓度与相对强度之间的线性关系,计算出样品中锡的含量。实验中可以将锡的分析上限提高到x%,同时避免由稀释样品带来的分析误差。方法相对标准偏差(RSD,n=12)小于7%,测定了国家一级地球化学标准物质,结果与标准值相符。     

银精矿成分分析系列标准物质研制

研制了系列银精矿标准物质。从日常检验样品中收集了15个不同含量的银精矿样品，每个样品收集5～8个批次，根据预留样品各元素成分含量综合考量后，筛选出4个不同品位的银精矿质控样品作为标准物质候选物，对标准物质候选物进行破碎、筛分、混匀及缩分，然后进行均匀性检验、稳定性进行检验，再由6家权威实验室进行协作定值，并对不确定度进行评定。结果表明，所研制的银精矿标准物质具有良好的均匀性和稳定性。该系列银精矿标准物质共定值6种元素，包括Pb(15%～56.99%)、Au(0.22～1.59 g/t)、Ag(2 913.6～4 855.0 g/t)、Cu(0.21%～1.16%)、As(0.12%～1.87%)、Zn(3.33%～10.58%)，制备过程及定值结果符合国家一级标准物质的规定。     

铝锰铁合金标准物质的研制

依据GB/T15000.3—2008、GB/T15000.5—1994、YB/T082—1996和相关ISO导则研制了铝锰铁合金化学分析用标准样品。样品经过加工混匀后,按要求进行粒度实验和均匀性检验。采用Minitab软件进行均匀性数据的正态性检验,然后用方差法进行均匀性检验,各元素F值均小于临界值F0.05,表明被检元素的均匀性良好。由7家有资质的实验室采用多种不同原理,准确、可靠的分析方法协作定值分析,对分析结果进行统计和处理,得到了定值元素的认定值。结果表明该标准物质均匀性和稳定性以及定值准确性均达到国家标准物质的性能指标,符合国家计量技术规范的要求。     

锰纯度定值及其单元素溶液标准物质的研制

以高纯锰为原料研制锰单元素溶液标准物质。采用电感耦合等离子体质谱法、电感耦合等离子体发射光谱法以及元素分析仪3种方法测定高纯锰中杂质元素的含量,并通过杂质扣除法确定了高纯锰的纯度为(99.95±0.04)%(k=2)。采用重量–容量法制备了锰单元素溶液标准物质,以配制值作为锰单元素溶液标准物质的标准值。对溶液标准物质的均匀性和稳定性进行了检验,其均匀性与稳定性良好。对标准物质的不确定度进行了评定。锰单元素溶液标准物质的浓度值为100μg/mL,相对扩展不确定度为0.8%(k=2)。该标准物质的量值准确,可用于锰元素的分析检测、检测方法评价与仪器校准。     

大米成分分析标准物质的研制

从辽宁盘锦、四川简阳和湖南岳阳采集3个大米标准物质为候选物,粉碎至粒径小于0.18 mm的颗粒,并充分混匀.采用X-射线荧光光谱法进行均匀性检验,采用等离子体质谱法进行稳定性检验,结果显示制备的大米标准物质均匀性、稳定性良好.由14家实验室联合定值,采用高灵敏度、高精度的方法测试了58种元素,其中43种元素给出标准值.     

石墨炉原子吸收测定土壤中的Cd Pb

摘要：为了提升石墨炉原子吸收测定土壤样品中Cd和Pb的准确度和测试效率,对样品前处理和仪器测试等条件进行优化选择,确定了低温电热板消解样品时,硝酸、氢氟酸、高氯酸的三酸比例和复溶方式以及采用海光GGX-920型石墨炉原子吸收测定Cd和Pb的升温程序、样品和基体改进剂加入量等条件。应用选定方法条件分别对土壤标准物质GBW07403、GBW07449水系沉积物 GBW07309进行6次测定,测定值Cd的相对标准偏差RSD：2.49%~4.67%,相对误差RE：-2.31% ~ 2.22%,测定值Pb的相对标准偏差RSD：1.98%~ 2.54%,相对误差RE：-1.88% ~ 2.11%。此方法精密度和准确度均达到标准要求,是一种准确而快速的检测方法,适合大批量的环境样品检测。     

临床实验室标准物质氯化钠的研究与测定

用重量法测定氯化钠中的钠含量(Na_实~+/Na_理~+),测定值为99.97％,标准偏差0.02％,总不确定度0.04％,并作了样品的均匀性、稳定性检验。用精密摩仑滴定法测定氯化钠中氯的含量(Cl_实~+/Cl_理~+),测定位99.993％,标准偏差0.005％,并作了样品的均匀性检验。结果表明,氯化钠中钠和氯的含量均符合临床实验室标准物质技术规范要求,达到国际同类标准物质先进水平。     

高频红外碳硫仪测定区域地球化学样品中的硫

高频红外碳硫仪由于便捷高效,常应用于区域地球化学样品中硫的分析检测。本文采用高频红外碳硫仪测定低中高含量的硫,以纯铁屑、锡粒和钨粒为助熔剂,对样品称样量、助熔剂的种类、加入顺序和用量等因素进行探讨,确定了最佳分析岩石、土壤和水系沉积物中硫含量的条件,并且用国家一级标准物质验证了该方法的准确度和精密度。结果表明,当样品和助熔剂的加入顺序和质量分别为：0.05 g样品、0.5 g铁助熔剂、1.7 g钨粒时,土壤和水系沉积物中硫的测定结果最稳定,岩石标准样品额外的加入0.5 g锡改善样品流动性,提高分析准确度。该方法的相对标准偏差（RSD）小于6%（n= 12）,相对误差绝对值小于8%。此方法具有操作简单、高效、稳定性好的特点,适合于大批量区域地球化学样品中硫的检测。     

Precise determination of boron in titanium by inductively coupled plasma mass spectrometry

A method was developed for the determination of boron in titanium by inductively coupled plasma mass spectrometry (ICP-MS). A commercially available PTFE sample introduction system, leading to the desired low detection limits for boron, was used. The method is suitable for the determination of boron concentrations down to about 1 μg g^?1 in the solid material. The influence of the internal standard on the precision was studied and beryllium was selected as the internal standard. For the titanium analysed (BCR reference material 090), the ICP-MS result agreed with those obtained using other techniques. Several bars of titanium reference material were supplied and a study of the homogeneity of boron in this material was made. Using analysis of variance on the results obtained for the different bars, the homogeneity of boron in the reference material could be estimated to be better than 2.1%.     

Multielement analysis of whole blood by high resolution inductively coupled plasma mass spectrometry

An analytical method using double focusing sector field inductively coupled plasma mass spectrometry (ICP-SMS) for rapid simultaneous determination of 50 elements in digested human blood is described. Sample preparation consisted of microwave digestion with nitric acid followed by dilution with ultrapure water. The importance of controlling possible contamination sources at different sample preparation and analysis stages in order to achieve adequate method detection limits (MDL) is emphasised. Correction for matrix effects was made using scandium, indium and lutecium as internal standards. Accuracy of the data for elements suffering from spectral interferences was improved by applying either a high resolution capability of the ICP-SMS or mathematical corrections. Different approaches for accuracy assessment in blood analysis are evaluated. Additional information on trace elements concentration in selected blood reference materials is given. The between-batch precision was assessed from replicate analysis (including sample preparation) of reference materials and was better than 10% RSD for 21 elements and better than 30% RSD for 36 elements under consideration. A statistical summary for results obtained for 31 blood samples from non-exposed subjects is presented. The majority of elements tested was found in the samples at concentrations higher than MDL.     

Development of a reference material for residues of chlorfluazuron and fluazuron in beef fat ACSL CRM 3

A beef fat sample was prepared and tested as candidate reference material for the pesticides chlorfluazuron (CFZ) and fluazuron (FZN). An analytical method employing HPLC with UV absorbance detection was developed for homogeneity and stability testing. The material consisted of beef fat spiked with acetone solutions of CFZ and FZN to achieve concentrations close to 1.0 mg/kg for each compound. The coefficients of variation of 7 analyses carried out to test between-jar homogeneity were 1.8% and 2.3% for FZN and CFZ, respectively. No instability of CFZ was detected over a three month period. The candidate reference material was found to be suitable for certification by interlaboratory testing.     

Multielement analysis of whole blood by high resolution inductively coupled plasma mass spectrometry

An analytical method using double focusing sector field inductively coupled plasma mass spectrometry (ICP-SMS) for rapid simultaneous determination of 50 elements in digested human blood is described. Sample preparation consisted of microwave digestion with nitric acid followed by dilution with ultrapure water. The importance of controlling possible contamination sources at different sample preparation and analysis stages in order to achieve adequate method detection limits (MDL) is emphasised. Correction for matrix effects was made using scandium, indium and lutecium as internal standards. Accuracy of the data for elements suffering from spectral interferences was improved by applying either a high resolution capability of the ICP-SMS or mathematical corrections. Different approaches for accuracy assessment in blood analysis are evaluated. Additional information on trace elements concentration in selected blood reference materials is given. The between-batch precision was assessed from replicate analysis (including sample preparation) of reference materials and was better than 10% RSD for 21 elements and better than 30% RSD for 36 elements under consideration. A statistical summary for results obtained for 31 blood samples from non-exposed subjects is presented. The majority of elements tested was found in the samples at concentrations higher than MDL. Received: 23 November 1998 / Revised: 6 January 1999 / Accepted: 12 January 1999