272 resultados para ICP
Resumo:
Artificial neural network(ANN) approach was applied to classification of normal persons and lung cancer patients based on the metal content of hair and serum samples obtained by inductively coupled plasma atomic emission spectrometry (ICP-AES) for the two groups. This method was verified with independent prediction samples and can be used as an aiding means of the diagnosis of lung cancer. The case of predictive classification with one element missing in the prediction samples was studied in details, The significance of elements in hair and serum samples for classification prediction was also investigated.
Resumo:
根据电感耦合等离子体原子发射光谱(ICP-AES)分析的实际需要,开发了一种ICP-AES分析信息系统。该系统包括谱线管理系统、识别干扰程度系统、校准及干扰校正系 统、帮助系统等子系统。本文将讨论系统分析。系统设计和系统评价将在另文中讨论。
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讨论了系统设计和系统评价。首先,根据ICP-AES中有关信息在计算机中的流动、 转换、储存和处理情况设计了计算机流程图,然后根据数据库规范化的要求对数据库的概念 结构、逻辑结构和物理结构的设计作了讨论。该数据库包括了28000余条ICP发射谱线的有 关数据。运行结果表明,该系统设计合理,信息量大,且具有方便、实用的用户界面。
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本文采用2-乙基己基膦酸单(2-乙基己基)酯(P-507)树脂,使微量稀土元素与钢中的基体元素,铁、钛、钒和钼分离,以 3.0 mol/L盐酸溶液洗脱P-507色层柱上的稀土元素,采用电感耦合等离子体原子光谱法(ICP-AES)同时测定了钢中La、Ce、Pr、Nd、Sm、Y和 Gd 7种微量稀土元素.试样的标准加入回收率99.3%~108%;相对标准偏差小于5%.
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本文采用苯甲酰苯胲(BPHA)-甲基异丁基酮(MIBK)溶剂萃取方法将钢中基体元素Fe,Ti,Mo,V等大量非稀土元素萃入有机相中,稀土元素留于水溶液中.由电感耦合等离子体原子发射光谱(ICP-AES)仪直接测定水溶液中的微量稀土元素La,Ce,Pr,Nd.Sm,Y和Gd,实验结果与推荐值基本相符,方法的回收率为96%~108%,相对标准偏差低于5%.
Resumo:
Effects of some factors on the performance of our Kalman filter in discrimination of closely spaced overlapping signals were investigated. The resolution power of the filter for overlapping lines can be strengthened by reduction of the step size in scans. The minimum peak separation of two lines which the Kalman filter can effectively handle generally equals two to three times the step size in scans. Significant difference between the profiles of the analysis and interfering lines and multiple lines from matrix in the spectral window of the analysis line are very helpful for the Kalman filter to discern closely spaced analysis and interfering signals correctly, which allow the filter well to resolve the line pair with very small peak distance or even the entirely coincident lines.
Resumo:
The present paper reports some definite evidence for the significance of wavelength positioning accuracy in multicomponent analysis techniques for the correction of line interferences in inductively coupled plasma atomic emission spectrometry (ICP-AES). Using scanning spectrometers commercially available today, a large relative error, DELTA(A) may occur in the estimated analyte concentration, owing to wavelength positioning errors, unless a procedure for data processing can eliminate the problem of optical instability. The emphasis is on the effect of the positioning error (deltalambda) in a model scan, which is evaluated theoretically and determined experimentally. A quantitative relation between DELTA(A) and deltalambda, the peak distance, and the effective widths of the analysis and interfering lines is established under the assumption of Gaussian line profiles. The agreement between calculated and experimental DELTA(A) is also illustrated. The DELTA(A) originating from deltalambda is independent of the net analyte/interferent signal ratio; this contrasts with the situation for the positioning error (dlambda) in a sample scan, where DELTA(A) decreases with an increase in the ratio. Compared with dlambda, the effect of deltalambda is generally less significant.
Resumo:
The present paper deals with the evaluation of the relative error (DELTA(A)) in estimated analyte concentrations originating from the wavelength positioning error in a sample scan when multicomponent analysis (MCA) techniques are used for correcting line interferences in inductively coupled plasma atomic emission spectrometry. In the theoretical part, a quantitative relation of DELTA(A) with the extent of line overlap, bandwidth and the magnitude of the positioning error is developed under the assumption of Gaussian line profiles. The measurements of eleven samples covering various typical line interferences showed that the calculated DELTA(A) generally agrees well with the experimental one. An expression of the true detection limit associated with MCA techniques was thus formulated. With MCA techniques, the determination of the analyte and interferent concentrations depend on each other while with conventional correction techniques, such as the three-point method, the estimate of interfering signals is independent of the analyte signals. Therefore. a given positioning error results in a larger DELTA(A) and hence a higher true detection limit in the case of MCA techniques than that in the case of conventional correction methods. although the latter could be a reasonable approximation of the former when the peak distance expressed in the effective width of the interfering line is larger than 0.4. In the light of the effect of wavelength positioning errors, MCA techniques have no advantages over conventional correction methods unless the former can bring an essential reduction ot the positioning error.
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本文提出了以PGS-2型平面光栅摄谱仪与Plasma Therm ICP-5000D射频发生器联用,乙醇溶液预去溶进样方法,直接同时测定高纯氧化钬中5个稀土杂质元素的方法,并讨论了基体浓度对分析方法检出限的影响和光谱干扰及其校正。当样品溶液中稀土总浓度为5mg/ml时,测定下限分别为铽0.003%,镝、铒和铥0.002%,钇0.0003%。其相对标准偏差为2.8%~7.4%。
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本文研究了ICP-AES测定Mg-Nd合金样品中10种元素的分析方法。选择了同时测定合金中La、Ce、Pr、Sm、Fe、Al、Mo、Ni、Cu和高含量Nd(20%)的条件。得到了满意结果。
Resumo:
某些稀土杂质对高纯金属镨的冶炼与性质有很大影响,因此需建立准确可靠的分析方法。镨的ICP光谱极为复杂,本文除用乙醇预去溶进样方式以提高分析灵敏度外,还研究了基体用量和稀土元素间的光谱干扰和校正方法。得出当样品中稀土总浓度为5mg/mL时,可直接同时测定纯度>99.99%的高纯金属镨中的镧、铈、钕、钐和钇,测定下限分别为镧、钕和钐0.002%,铈0.003%,钇0.0005%;其相对标准偏差分别为2.2%,6.2%,3.6%,1.4%和
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针对ICP-AES中严重重叠谱线干扰的校正,研究了若干因素对Kalman滤波器性能的影响.减小扫描步长可以增强Kalman滤波法解析重叠谱线的能力.当重叠线对轮廓基本相同且扫描窗口内干扰元素只有一条谱线时,Kalman滤波法能分辨的重叠线对的最小峰间距为扫描步长的2~3倍.扫描窗口内较多的干扰元素谱线和重叠线对轮廓的显著差异有利于Kalman滤波器正确识别分析信号和干扰信号,可以利用这两个因素有效地分辨峰间距很小甚至完全重叠的谱线.
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本文研究了长白山自然保护区大气降水(雨水或雪水)中的多元素分析。采用ICP-AES法测定水中的K、Na、Ca、Mg、Mn、Fe、Sr、Ba、Cu、Zn、Ni和V等元素,用干扰系数法对光谱干扰进行修正。为该地区天气环境背景值和大气污染现状提供了富贵资料。
Resumo:
本文提出了PGS-2型平面光栅光谱仪(色散率0.18纳米,二级光谱)与Plasma Therm ICP-5000D射频发生器联用,乙醇预去溶方式进样,同时直接测定高纯金属镨中5个痕量稀土杂质元素的方法。并讨论了基体浓度对检出限的影响以及光谱干扰及其校正方法。当样品溶液中镨的浓度为5毫克/毫升时,测定下限分别为镧、钕和钐0.002%,铈0.003%和钇0.0005%。获得了良好的实验结果,并相对标准偏差为1.2-6.2%。
Resumo:
A Kalman filter was developed for resolving overlapping lines in inductively coupled plasma atomic emission spectrometry (ICP-AES) and evaluated experimentally with the determination of La in the presence of Ho, and Cu in the presence of Pr. The whiteness of the innovation sequence for an optimal filter was explored to be the criterion for the correction of the wavelength positioning errors which may occur in spectral scans. Under the conditions of the medium-resolution spectrometer and 1.5 pm step size in scans, the filter effectively resolved the Cu/Pr line pair having a small peak separation of 4.8 pm. For the La/Ho line pair with a peak distance of 9.8 pm, an unbiased estimate for La concentration was still obtained even when the signal-to-background ratio was down to 0.048. Favourable detection limits for real samples were achieved. Unstructured backgrounds were modeled theoretically and all spectral scans therefore did not require the correction for solvent.