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采用国家标准方法ICP-MS法测定高纯金中的杂质元素时,利用传统湿法消解样品后,大量金基体对杂质元素测定产生干扰和抑制作用,影响测定结果的准确度。实验建立微波消解-萃取—ICP-MS法测定高纯金中杂质元素的方法,并对微波消解-萃取条件进行优化,提高金溶解率及金萃取率,消除金基体对杂质元素测定的干扰。该方法可同时测定40种杂质元素,检出限为0.01~0.29μg/g,测定结果相对标准偏差(n=6)为1.29%~4.18%,加入标准物质回收率为86.94%~115.55%,准确度和精密度良好。 相似文献
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钽铌矿石样品加入氢氟酸、硝酸、盐酸,通过高压密闭装置消解样品,采用ICP-OES同时测定钽铌矿石中钨铜钛元素。探讨了基体对被测元素的影响,选择了合适的溶样时间和分析谱线。结果表明:此方法同时测定钽铌矿石中的铜钨钛元素,在0.050%~1.0%范围内,各元素测定工作曲线线性关系良好,线性相关系数≥0.999 7;元素检出限分别为:钨0.013%、铜0.002 0%、钛0.002 1%;加标回收率在96.0%~107.5%之间,结果的相对标准偏差(RSD,n=11)不大于1.93%。该方法适用于钽铌矿石中钨铜钛元素的同时测定。 相似文献
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用标准加入法以电感耦合等离子体质谱测定金属中铝、铜、钛、锌、锰、钴,建立了一种简便、快速测定金属铝中杂质元素的分析方法。实验中考察了5元素同时测定的仪器参数、Rh内标的校正作用,以及酸度、样品基体效应等因素对测定结果的影响。各元素回收率在90.8%~123%间,检出限均<1.5ng/mL,测定下限为0.0001%,相对标准偏差均<10%。 相似文献
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建立了ICP-OES法快速测定金属钐粉中铁、硅、铝、锰、镁、钛、钙、钼、钽、铌含量的测定方法。考察了钐基体对杂质元素测定的光谱干扰,采用高纯氧化钐作为配置标准曲线的基体,与金属钐样品基体匹配,消除钐基体对杂质元素测定的光谱干扰,并用标准曲线法进行测定。方法的检出限为0.02~2.85μg/g,加标回收率为91.0%~107.6%,测定精密度(RSD)为2.7%~10.7%。方法简便快速,适用于生产分析。 相似文献
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在电感耦合等离子体原子发射光谱基础上用标准加入法对纯铜中砷、铋、铁、镍、磷、铅、硫、锑、锡和锌10种杂质元素的测定进行了研究。由于工作溶液是在样品溶液中加入被测元素的标准溶液而得到,工作溶液与样品溶液具有相同基体,因此可以消除基体干扰对测定的影响。同时在测定时不需要另配制以铜打底的校准溶液,不但操作简单,而且能减少杂质元素引入,提高了方法的准确度。本法用于纯铜中杂质元素的测定,回收率为96%~108%,完全能满足纯铜样品中杂质元素的分析检测要求。 相似文献
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国家标准方法测定金矿石中的铅、锌、砷、铋、镉和汞需多次溶样,操作繁琐。研究建立了混合酸消解,电感耦合等离子体原子发射光谱法同时测定金矿石中铅、锌、砷、铋、镉和汞的分析方法。实验对混合酸加入量、氟化氢铵溶液加入量、消解温度、消解时间等影响因素进行了优化。该方法各元素加入标准物质回收率为98.0%~104.0%,测定结果的相对标准偏差(n=11)为0.60%~4.76%,且与国家标准方法测定结果一致,具有操作简单,一步消解、多元素同时测定,检测效率高等优点,适用于大批量金矿石样品的检测。 相似文献
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试验研究建立了同一试料溶液连续、同时测定铂饰品中各成分的分析方法。主体Pt以氯铂酸铵称量法及火焰原子吸收光谱(FAAS)法或电感耦合等离子发射光谱(ICP-AES)法测定滤液中残留Pt进行补差而测定。主成分Pd,Au,Ag,Cu和焊料成分Ni,Zn,Fe以FAAS法或ICP-AES法测定。其方法回收率分别为:Pt99.9%~100%;Pd99.3%~99.7%;Au99.5%~l01.5%;Ag98.0%~100%;Cu97.7%~99.3%;Zn98.0%~99.0%;Ni94.0%~105%;Fe95.0%~99.0%。实际试样分析时,各成分质量分数之和一般在99.12%~l01.2%之间,接近于100%,间接说明方法的可靠性。本法适用于Pt-Pd二元体系和Pt-Pd-Au-Cu多元复杂体系的铂饰品的破坏分析,可用于校正X荧光光谱法无损检测铂饰品的分析结果。 相似文献
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JC Leonard HL Drwinga CH Kim LH Toji PK Bender RA Mulivor JC Beck 《Canadian Metallurgical Quarterly》1997,46(3):530-534
The erm family of 23S rRNA adenine-N6-methyltransferases confers resistance to all macrolide-lincosamide-streptograminB (MLS) antibiotics, but not all MLS antibiotics induce synthesis of Erm methyltransferase with equal efficiency in a given organism. The induction efficiency of a test panel of MLS antibiotics was studied by using two translational attenuator-lac reporter gene fusion constructs, one based on ermSV from Streptomyces viridochromogenes NRRL 2860 and the other based on ermC from Staphylococcus aureus RN2442. Four types of responses which were correlated with the macrolide ring size were seen, as follows: group 1, both ermSV and ermC were induced by the 14-membered-ring macrolides erythromycin, lankamycin, and matromycin, as well as by the lincosamide celesticetin; group 2, neither ermSV nor ermC was induced by the 12-membered-ring macrolide methymycin or by the lincosamide lincomycin or the streptogramin type B antibiotic ostreogrycin B; group 3, ermSV was selectively induced over ermC by the 16-membered-ring macrolides carbomycin, chalcomycin, cirramycin, kitasamycin, maridomycin, and tylosin; and group 4, ermC was selectively induced over ermSV by the 14-membered-ring macrolide megalomicin. These data suggest that the leader peptide determines the specificity of induction by different classes of MLS antibiotics and that for a given attenuator, a major factor which determines whether a given macrolide induces resistance is its size. 相似文献
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稀土金属中14种非稀土杂质的ICP-MS法同时测定 总被引:1,自引:0,他引:1
本文研究了用 ICP- MS仪器同时测定稀土金属中 Mg、Al、Ti、Cr、Mo、Mn、Co、Ni、Cu、Zn、Pb、W、Nb、Ta等 14种非稀土杂质。研究了各稀土基体对被分析元素的基体效应 ,选择了相匹配的内标元素。比较了标准曲线法与标准加入法的测定结果。确定了用内标元素校正基体效应及仪器漂移 ,以标准曲线法直接测定。进行了加料回收和精密度实验 ,回收率在 94%~ 113%之间 ,RSD<10 %。被分析元素的检出限为 0 .0 1~ 0 .2 0 ng/ m L,测定下限为1~ 2 0 μg/ g。 相似文献
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MR Thompson R Venkatesan K Kuppusamy A Celik W Lin DK Kido EM Haacke 《Canadian Metallurgical Quarterly》1999,210(1):253-259
An insertable head gradient coil with a maximum gradient amplitude of 45 mT/m and a rise time of 150 musec along all three major axes was used to collect high-spatial-resolution, single-shot, spin-echo, echo-planar, diffusion-weighted magnetic resonance images with b values ranging from 0 to 2,200 sec/mm2. Improvements in spatial resolution allowed better visualization of large white matter tracts and their relation to adjacent anatomic structures. Excellent contrast and anatomic detail were revealed for most structures in the brain when a sufficient number of acquisitions were collected. 相似文献
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土壤无机污染物铅、铬、镉、汞、砷、锌、铜、镍这八大重金属,是一般土壤检测中的必检项目。金属元素在土壤中积累富集后,有可能通过雨水迁移,造成地下水,地表水污染,或者通过农作物进入食物链,进而影响食品安全和人体健康,因此,对这些元素的检测显得尤为重要。本文采用原子荧光光谱法对土壤中的金属元素进行测量,同时结合微波消解技术对样品进行处理,确保测量数据的准确性。 相似文献
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Agar dilution MICs of 10 agents against 410 non-Pseudomonas aeruginosa gram-negative nonfermentative rods were determined. MICs at which 50 and 90% of the isolates were inhibited, respectively, were as follows (in micrograms per milliliter): sparfloxacin, 0.5 and 8.0; levofloxacin, 1.0 and 8.0; ciprofloxacin, 2.0 and 32.0; ofloxacin, 2.0 and 32.0; D-ofloxacin, 32.0 and > 64.0; ceftazidime, 8.0 and 64.0; piperacillin with or without tazobactam, 16.0 and > 64.0; trimethoprim-sulfamethoxazole, 0.5 and > 64.0; imipenem, 2.0 and > 64.0. With the exception of those for Stenotrophomonas maltophilia, Burkholderia cepacia, and Alcaligenes faecalis-A. odorans, agar dilution MICs for all strains tested were within 1 dilution of inhibitory (bacteriostatic) levels as determined by time-kill methodology. 相似文献
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