HG-ICP-MS同时测定生物样品中痕量As,Se,Hg

以HNO3为介质,采用自行研制的二级气液分离器代替易消耗的膜分离器,在优化的实验条件下,采用HG-ICP-MS实现了As,Se,Hg的同时测定,分别获得了0.022,0.016,0.009 ngmL的检出限。实验研究了二级气液分离器中的气液分离行为、样品酸度、NaBH4质量浓度和引入方式等因素对测定灵敏度和精密度的影响。实验的结果表明,HG-ICP-MS同时测定As,Se,Hg的主要干扰来自于Fe,cu等过渡金属离子,样品溶液中抗坏血酸-硫脲的加入可以掩蔽这些离子的干扰。利用所建立的方法测定了人发、灌木叶和大米粉标样中痕量的As,Se,Hg,结果与标准参考值相符。     

电感耦合等离子体质谱法测定血液和精液中的硼

采用HNO3-H2O2和氨水-甘露醇两种方法处理样品,电感耦合等离子体质谱法（ICP-MS）测定血液和精液中的硼。Be作内标补偿基体效应,并用标准加入法验证了方法的可靠性,标准加入法与外标法测定结果相吻合。在测定B的同时,还可进行Cr、Cu、Cd、Ba、Sr、Mn、Co、Tl、Li、Pb、Zn、Sc、Ti、V、As等多元素测定。两种样品处理方法的测定值呈显著正相关（r=0.99919）。方法检出限为0．11ng／mL（氨水-甘露醇法）,0.06ng／mL（HNO3-H2O2）。已用于测定某硼矿区血液和精液样品中的硼。     

Application of double-spike isotope dilution for the accurate determination of Cr(III), Cr(VI) and total Cr in yeast

A method is presented for the simultaneous determination of Cr(III) and Cr(VI) in yeast using species-specific double-spike isotope dilution (SSDSID) with anion-exchange liquid chromatography (LC) separation and sector field inductively coupled plasma mass spectrometric (SF-ICP-MS) detection. Total Cr is quantitated using ID SF-ICP-MS. Samples were digested on a hot plate at 95±2 °C for 6 h in an alkaline solution of 0.5 M NaOH and 0.28 M Na₂CO₃ for the determination of Cr(III) and Cr(VI), whereas microwave-assisted decomposition with HNO₃ and H₂O₂ was used for the determination of total Cr. Concentrations of 2,014±16, 1,952±103 and 76±48 mg kg⁻¹ (one standard deviation, n=4, 3, 3), respectively were obtained for total Cr, Cr(III) and Cr(VI) in the yeast sample. Significant oxidation of Cr(III) to Cr(VI) (24.2±7.6% Cr(III) oxidized, n=3) and reduction of Cr(VI) to Cr(III) (37.6±6.5% Cr(VI) reduced, n=3 ) occurred during alkaline extraction and subsequent chromatographic separation at pH 7. Despite this significant bidirectional redox transformation, quantitative recoveries for both Cr(III) and Cr(VI) were achieved using the SSDSID method. In addition, mass balance between total Cr and the sum of Cr(III) and Cr(VI) concentrations was achieved. Method detection limits of 0.3, 2 and 30 mg kg⁻¹ were obtained for total Cr, Cr(VI) and Cr(III), respectively, based on a 0.2-g sub-sample.     

Use of enriched <Superscript>74</Superscript>Se and <Superscript>77</Superscript>Se in combination with isotope pattern deconvolution to differentiate and determine endogenous and supplemented selenium in lactating rats

A quantitative methodology has been developed to differentiate between endogenous and supplemented selenium in lactating rats using two enriched selenium isotopes. Lactating rats were fed for 2 weeks with formula milk containing one enriched Se isotope, ⁷⁷Se, as the metabolic tracer. The isotopic composition of selenium in serum and urine samples was then measured by collision cell ICP-MS after the addition of a solution containing another enriched isotope, ⁷⁴Se, as quantitation tracer, before analysis. Isotope pattern deconvolution allowed the transformation of measured Se isotopic abundances into concentrations of natural abundance (endogenous) selenium and enriched ⁷⁷Se (supplemented) present in the samples. The proposed methodology was validated using serum and urine reference materials spiked with both ⁷⁷Se and ⁷⁴Se. The obtained results are discussed in terms of selenium exchange and half-life in lactating rats (11–12 days) and selenium levels in serum in comparison with non-supplemented rats and control rats after maternal feeding.     

Towards the characterization of metal binding proteins in metal enriched yeast

This paper presents size exclusion chromatography data with on-line coupling to UV and inductively coupled plasma mass spectrometry (ICP-MS) of water soluble metal-binding compounds present in zinc, copper, chromium and iodine enriched yeast nutritional supplements. Molecular weight estimates of the extracted metal-containing compounds are given and are shown to vary substantially from 1.2 kDa to larger than 668 kDa. Seven proteins suspected of containing chromium were identified from one of the chromium-containing fractions. Four of these identified proteins are known to form complexes with other metal ions. The metal chromatographic profiles of zinc, copper and chromium-enriched yeasts were compared to their respective native metal profiles in non-enriched yeast samples. The chromium profiles are shown to be markedly different while those of zinc and copper are qualitatively similar. Only iodide ions or weakly bound, non-aromatic, low molecular weight ( 1.2 kDa) iodine species were observed in the iodine-enriched yeast samples.     

微波消解/ICP MS法测定不同地点虎耳草中16种元素含量

利用微波消解/ICP-MS法对3个地点虎耳草中16种元素进行了含量测定.结果表明,不同地点虎耳草元素的含量相差较大,虎耳草中Ca元素与海拔高度呈线性关系.该法的加样回收率在95.3%～105.0%之间,相对标准偏差在0.98%～2.82%之间,具有较高的准确度和精确度.结果为虎耳草的药效性和药理毒理提供了理论依据.     

便携式气相色谱-质谱联用仪的研制及应用

将双曲面三维离子阱质谱技术与低热容气相色谱技术相结合,研制了便携式气相色谱-质谱联用仪(GC-MS).此仪器主要由进样系统、低热容气相色谱模块、气质接口以及小型化离子阱质谱模块等构成,其主机重量小于14 kg,体积为44 cm×36 cm×22 cm,功耗小于100W.该仪器中的离子阱质谱仪系统具有15～550 amu...     

微波消解-ICP-MS法测定药用明胶空心胶囊中微量重金属元素

采用微波消解技术,建立了一种电感耦合等离子体质谱法测定明胶空心胶囊中Cr,Co,Ni,Cu,Zn,As,Cd,Hg和Pb 9种微量重金属元素的方法。确定了微波消解仪和等离子体质谱仪的最佳操作参数,研究共存离子的干扰和消除方法,选择了各元素的测定同位素,以Ge,Rh和Tl为内标补偿基体效应,建立了样品测定方法。应用拟定的方法测定了不同生产厂家、不同批次的空心胶囊中微量重金属的含量。方法对试样中各元素测定的相对标准偏差为1.5%~14.1%,加标回收率在90.0%~102.0%。结果表明,方法简便、快速、灵敏,满足于空心胶囊中9种重金属元素的测定要求。     

微波消解-ICP-MS测定塑料原料中14种催化剂残留元素

采用微波消解法预处理聚乙烯(PE)、聚丙烯(PP)、聚苯乙烯(PS)、聚对苯二甲酸乙二醇酯(PET)常用塑料原料,使用压力控制装置对消解过程进行监控并对消解条件进行摸索,考察了消解量、消解体系、消解温度和保持时间对消解结果的影响,优化选择了电感耦合等离子体-质谱法(ICP-MS)的测定参数和内标元素。建立了微波消解-电感耦合等离子体-质谱法测定塑料原料中Li、Ca、Mg、Al、Si、Ti、V、Cr、Co、Zn、Ga、Zr、Sb、Hf 14种元素的催化剂残留的检测方法。方法检出限在0.001～10.60μg/L,回收率在82%～120%之间,相对标准偏差小于20%。     

电感耦合等离子体质谱法测定海洋贝类中镉、铬、铜和铅

采用微波消解法处理海洋贝类样品,用电感耦合等离子体质谱法测定样品中镉、铬、铜和铅等4种重金属元素的含量。选择111 Cd、53 Cr、63 Cu和208 Pb等待测元素的同位素克服了质谱干扰。4种元素分别在一定的质量浓度范围内呈线性,检出限(3s)在0.005～0.17μg.L-1之间。镉、铬、铜和铅的回收率分别为94.7%,102.1%,101.9%,105.3%;测定值的相对标准偏差(n=7)分别为4.3%,3.8%,1.5%,6.0%。