氢化物发生-原子荧光光谱法测定恩施富硒土壤中的总硒

采用氢化物发生-原子荧光光谱法测定恩施富硒土壤中的总硒,优化了各项实验条件,确定了最佳方法。在最佳实验条件下,方法的检出限为0.04μg/L,线性范围为0.12—80μg/L,RSD为0.87%。测得样品含量在3.449—115.070μg/g之间,回收率为97.8%—101.1%,方法简单、结果准确、重现性好,适合测定富硒土壤中的总硒含量。     

氢化物发生-原子荧光光谱法测定钢铁中硒的含量

采用氢化物发生-原子荧光光谱法,考察了观察高度、负高压、灯电流、载气流速、屏蔽气流速、载流酸浓度和硼氢化钾浓度对钢铁中硒含量测定的影响,优化了测定条件.用硫脲-抗坏血酸做干扰抑制剂消除大量基体元素及常见元素对硒元素测定的干扰,确定了钢铁中痕量硒的分析方法.     

氢化物发生-原子荧光光谱法测定富硒丹参中的硒

采用氢化物发生-原子荧光光谱法对富硒丹参中硒的含量进行测定。用体积比为4∶1的硝酸-高氯酸敞开湿法消解丹参粉末样品。在优化的仪器条件和反应条件下,方法的定性检出限为0.118μg/L,定量下限为0.392μg/L,相对标准偏差为1.20%—2.27%,线性范围0—300μg/L,相关系数r=0.9999,加标回收率为92.25%—106.75%。丹参样品消解液的基体对硒的测定不产生干扰,采用校准曲线法可获得准确的结果。     

氢化物发生-原子荧光光谱法测定杏仁中的微量元素硒

本文采用氢化物发生-原子荧光光谱法测定杏仁中硒,此方法的回收率在97.0％-105.6％之间,RSD值在1.06％2.97％之间,方法可用于杏仁中硒的测定.结果表明新疆杏仁中硒含量较高.     

氢化物发生-原子荧光光谱法测定化妆品中的硒

硒是化妆品中的限用物质.应用氢化物发生-原子荧光光谱法测定化妆品中痕量的硒,样品用硝酸和高氯酸消解,盐酸可以使硒(Ⅵ)还原成硒(Ⅳ),硒(Ⅳ)与硼氢化钾反应产生硒化氢,硒化氢被带到原子化器,在最佳的条件下用原子荧光检测.这种方法测定化妆品中的硒,样品处理简单快速,方法的线性范围宽(0-20 μg/L),基体干扰少,检出限低(0.081 μg/L),加标回收率在96.05%-101.96%之间,相对标准偏差2.74%-2.99%.     

氢化物发生-原子荧光光谱法测定中草药中的硒

本文建立了氢化物发生-原子荧光光谱法测定中草药中的微量硒的分析方法。研究了仪器的工作条件、试剂对硒原子荧光强度的影响及硒(Ⅵ)的还原条件,探讨了共存离子对硒测定的干扰和消除方法,方法的检出限为0.21μg·L~(-1)。利用本方法成功地测定了10种中草药中的微量硒,回收率为95％～105％。方法简便、快速、灵敏、准确。     

氢化物发生-原子荧光光谱法测定豌豆中的硒

以HNO3-HClO4消解样品,用HCl将六价硒还原为四价硒,建立了氢化物发生-原子荧光光谱法测定豌豆中硒的方法.在选定的最佳实验条件下,方法的检出限为0.1 ng/mL,线性范围为0-80 ng/mL.应用于三种豌豆中硒的测定,回收率为90.5%-110.6%,RSD为2.0%-5.7%.     

微波消解氢化物发生原子荧光光谱法测定鱼中痕量硒

微波消解氢化物发生原子荧光光谱法 (HG- AFS)测定了鱼中痕量硒。硝酸 -过氧化氢消解样品 ,在3mol· L-1盐酸介质中产生氢化物 ,2 % (W/V) KBH4为还原剂 ,研究了微波消解条件、预还原条件。方法准确快速。用本法测定国家标准物质的结果与推荐值及国标法测定结果相一致     

氢化物发生-原子荧光光谱法测定饲料中的硒

样品经酸消解后,在6mol/L盐酸介质中产生氢化物,0.8%(W/V)KBH4为还原剂,氢化物发生-原子荧光光谱法测定饲料中的硒。方法具有灵敏度高,重现性好的优点,结果令人满意。检出限为1.75×10-4mg/kg,方法回收率为98.4%—101.4%。     

氢化物发生-原子荧光光谱法测定芹菜籽中的硒

本法采用湿法消解,氢化物发生-原子荧光光谱法测定芹菜籽中硒。研究了原子荧光光谱仪的参数和最佳试验条件,方法的线性方程为I=124.350C-21.041,相关系数r=0.9999,检出限为0.1007μg/L。结果表明,芹菜籽中硒的回收率在94.3%—111.1%之间。     

氢化物发生-原子荧光光谱法测定植物样品中的硒

建立了氢化物发生-原子荧光光谱法测定植物样品中硒的分析方法。研究了试剂及预还原方式对硒原子荧光强度的影响,探讨了共存离子对硒测定的影响和消除方法。在最佳消解条件和测定条件下,硒的线性回归方程为I=139.98c+27.71,线性范围为0～10ng.mL-1,相关系数为1.000 0,检出限为1.45ng.g-1。测定标准物质中硒的回收率为98.9%～101%,其平均值为100%。对灌木枝叶样品中的硒进行分析,其相对标准偏差为0.73%(n=9)。以国家标准物质(GSV-1)为监控样品,测定值与标准值吻合。该方法具有成本低、操作简单和高效分析的优点,并成功用于植物样品中硒的测定。     

Determination of As (III) and As(V) in sea water by hydride generation atomic fluorescence spectrometry

The present paper reports a method based on intermittent flow injection (FI) hydride generation (HG) combined with atomic fluorescence spectrometry (AFS) detection for the determination of As in sea water. Experimental conditions for FI-HG were optimized. 5.0% hydrochloric acid-0.1 mol x L(-1) citric acid solution was selected as the carrier flow as well as the sample medium, and 2% KBH4-0. 5% KOH was used as the reductant. An argon gas flow was used for carrying the generated arsine to the Ar-H2 flame for atomization. Organic species of arsenic cannot be generated arsine under the selected conditions. The real sea water samples collected at Zhanqiao seashore in Qingdao and more than 30 other areas were analyzed under optimized working conditions, and experiments verified that the determination of As(III) and As(V) could approximately assess the As pollution for marine water while organic arsenic in natural sea water was so slight that could be neglected in case large amount of samples should be analyzed.     

氢化物发生—原子荧光法测定不同产地绞股蓝及其根际土壤中As,Hg,Se

通过优化了的氢化物发生—原子荧光法测定了7个省产绞股蓝及其根际土壤中As,Hg,Se三种元素的含量,研究结果表明:7个省产绞股蓝中As,Hg,Se的含量存在较大差异,但As和Hg两种重金属元素含量均低于《药用植物及制剂进出口绿色行业标准》中As和Hg的限量标准。Se元素含量同根际土壤中Se元素含量显示极显著相关性,故湖北恩施富硒区产绞股蓝中Se含量明显高于其他6省产绞股蓝。研究结果可以初步判定,绞股蓝中Se元素主要来源于土壤,而As和Hg元素的积累则不同于Se元素,还可能受到大气气溶胶的干、湿沉降等因素的影响。     

Study on the interaction between methyl blue and human serum albumin by fluorescence spectrometry

The interaction of methyl blue (MB) with human serum albumin (HSA) was studied by fluorescence and absorption spectroscopy. The intrinsic fluorescence of HSA was quenched by MB, which was rationalized in terms of the static quenching mechanism. The number of binding sites and the apparent binding constants at different temperatures were obtained from the Stern-Volmer analysis of the fluorescence quenching data. The thermodynamic parameters determined by the van’t Hoff analysis of the binding constants (ΔH°=39.8 kJ mol⁻¹ and ΔS°=239 J mol⁻¹ K⁻¹) clearly indicate that binding is absolutely entropy-driven and enthalpically disfavored The efficiency of energy transfer and the distance between the donor (HSA) and the acceptor (MB) were calculated as 60% and 2.06 nm from the Förster theory of non-radiation energy transfer.     

悬浮液氢化物发生—原子荧光光谱法测定地质样品中痕量铋？…

提出一种固体粉末悬浮液中氢化物发生－原子荧光光谱法测定地质样品中痕量铋的新方法，经ＧＳＤ（国家水系沉积物标准样）系列标准分析验证，结果可靠。     

Review of fluorescence anisotropy decay analysis by frequency-domain fluorescence spectroscopy

This didactic paper summarizes the mathematical expressions needed for analysis of fluorescence anisotropy decays from polarized frequency-domain fluorescence data. The observed values are the phase angle difference between the polarized components of the emission and the modulated anisotropy, which is the ratio of the polarized and amplitude-modulated components of the emission. This procedure requires a separate measurement of the intensity decay of the total emission. The expressions are suitable for any number of exponential components in both the intensity decay and the anisotropy decay. The formalism is generalized for global analysis of anisotropy decays measured at different excitation wavelengths and for different intensity decay times as the result of quenching. Additionally, we describe the expressions required for associated anisotropy decays, that is, anisotropy decays where each correlation time is associated with a decay time present in the anisotropy decay. And finally, we present expressions appropriate for distributions of correlation times. This article should serve as a reference for researchers using frequency-domain fluorometry.     

水污染物的激光诱导荧光测定

简单介绍了激光诱导荧光（ＬＩＦ） 产生的机理。以３ 倍频Ｎｄ：ＹＡＧ 激光（ 波长３５５ｎｍ） 为激发源,研究了水中几种典型污染物的ＬＩＦ 谱。结果表明这些污染物可用ＬＩＦ 方法加以探测和鉴别。     

A review on the methods for correcting the fluorescence inner-filter effect of fluorescence spectrum

Fluorescence spectroscopy is frequently used to analyze the concentration of fluorescent materials in solution. However, in conventional fluorescence spectroscopy, the response between the fluorescence intensity and fluorophore concentration is nonlinear at high concentrations due to uncompensated inner-filter effects (IFE). Many methods to resolve this problem have been developed in recent decades. This review introduces the methods used to correct the IFE, including direct correction and parameter correction. Relevant detection parameters, including the materials, matrices, detection limits, detection instruments and relative standard deviations, are tabulated. The advantages and limitations of these correction techniques are also discussed. Finally, the methods used to correct for the IFE are summarized, and future research directions are discussed.     

荧光光谱法研究核黄素与核黄素结合蛋白的相互作用

运用荧光光谱研究了核黄素与核黄素结合蛋白的相互作用,并探讨了两者间的结合类型、结合常数、结合过程中热力学参数和能量转移。结果表明:核黄素结合蛋白内源荧光的猝灭是由于核黄素与蛋白质之间形成复合物,并符合静态猝灭机理。298,308,318K下核黄素与核黄素结合蛋白的结合常数分别为:5.35×108,1.54×108,0.56×108 L.mol-1。热力学数据表明核黄素与核黄素结合蛋白之间主要作用力为氢键和范德华力。Frster能量转移理论确定了核黄素与核黄素结合蛋白的作用距离与能量转移效率分别为0.70nm与0.39。利用同步荧光光谱研究了核黄素结合蛋白与核黄素结合过程中构象的变化。     

Kinetic studies of antimony and selenium atomization processes including a chemical modifier during their determination by electrothermal atomic absorption spectrometry

We have studied antimony and selenium atomization processes including a chemical matrix modifier (palladium-containing activated carbon) during their determination by electrothermal atomic absorption spectrometry. We have developed and fine-tuned an experimental setup for determining the kinetic characteristics (activation energy and frequency factor) for element atomization processes from measurements in the initial section of the analytical signal. We provide a rationale for the most likely mechanism for the interactions that occur. The results of the kinetic studies of the atomization processes showed that the modifier we developed was highly effective, as a result of formation of a thermally stable condensed system C-Pd-A (where A is the analyte). __________ Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 73, No. 4, pp. 530–534, July–August, 2006.