萃取催化动力学光度法测定痕量锡

１引言 萃取动力学分析既有动力学分析的高灵敏度,又能提高其选择性。特别对于室温下进行的催化反应,可以通过固定萃取时间控制指示反应进行的程度,为终止反应和研究反应机理提供了方便。该法用于锡的测定未见报道。本文研究了稀ＨＣｌ介质中,利用锡催化溴酸钾氧化邻氨基酚显色的指示反应,建立了测定痕量锡的萃取催化光度法。该法灵敏度高、选择性好,不经分离直接测定水、人发及岩石中的痕量锡,结果满意。２实验部分２．１仪器与试剂ＵＶ－２６０型分光光度计（日本岛津公司）;７２１－Ａ型分光光度计（厦门分析仪器厂）;锡标准溶…     

溴酸钾氧化荧光素动力学荧光法测定痕量亚硝酸根

基于稀硫酸介质中,亚硝酸根催化溴酸钾氧化荧光素,建立了动力学荧光法测定痕量亚硝酸根的新方法。本方法具有高灵敏度和高选择性,测定亚硝酸根的线性范围为2～80ng/ml,可用于直接测定水样中亚硝酸根。     

共振散射光谱法测定环境水样中痕量锡（Ⅱ）

在pH 4.3的缓冲介质中,痕量锡(Ⅱ)对氯酚红-人血白蛋白-十二烷基硫酸钠体系的共振散射光谱有明显的减弱作用,共振散射强度的减弱程度(△I)与锡(Ⅱ)的质量浓度之间在0.2～4.0μg·L-1范围内呈线性关系,检出限(3S/N)为0.12μg·L-1,用于3件环境水样中痕量锡(Ⅱ)的测定,测定结果的相对标准偏差(n=6)小于3.5 %,加标回收率为95.5%～100.6%.     

室温磷光分析法在我国的发展

室温磷光分析法是测定痕量有机化合物和生化物的高灵敏度和高选择性的一种新的测试手段，近２０年来在国外发展迅速，是当前分析化学研究中的热点和前沿。我国的研究工作虽赳不较晚，然而速度较快，现就室温磷光分析法在我国的发展作一回顾。     

GC-MS-MS法测定土壤中的16种多环芳烃

采用GC-MS-MS测定土壤中16种多环芳烃,分析测定时间为50 min左右。GC-MS-MS具有高选择性、高灵敏度,对于痕量物质分析在干扰物质存时也能分析良好。方法检出限为0.0004~0.002mg.Kg-1,添加三个不同浓度水平标准做方法回收率,在72.3%~103.2%。相对标准偏差均低于16.5%。适合于土壤中多环芳烃的分析测定。     

催化动力学光度法测定痕量碘

基于碘在高碘酸钾氧化亮绿SF增色反应中的催化活性 ,建立了高灵敏度、高选择性的催化动力学光度法测定痕量碘的方法 ,测定范围为 0 .5～ 10 μg·ml- 1,方法检出限为 0 .2 6μg·ml- 1,用于天然水的碘化物测定 ,获得满意结果     

银的离子交换树脂比色法的研究

本文根据Ag~+能与显色剂5-Br-2(2′吡啶偶氮)-5-二乙氨基酚、十二烷基硫酸钠、三乙醇胺形成稳定的带负电荷的四元络合物的特点,选用合适的阴离子交换树脂,进行了树脂比色法的研究,建立了高灵敏度测定Ag的树脂比色新方法,测定下限为ppb级,是目前光度法测定Ag的最灵敏方法之一,用于废水中痕量Ag的测定,效果良好。     

邻菲啰啉-H_2O_2-Sn(Ⅳ)化学发光体系的研究

测定痕量锡可采用分光光度法、荧光分析法等。目前,高灵敏度的化学发光分析法已用于多种金属离子的分析,但是,锡的化学发光分析尚未见报道。本文采用的反相流动注射化学发光分析(rFIA-CL)法是以试样作载流,定量注入试剂到试液流中的一种分析新技术。rFIA法能在一定程度上克服基线漂移,提高分析灵敏度,减少试剂消耗,且重现性好。我们观察到邻菲啰啉(phen)在碱性介质中被H_2O_2氧化时有较强的化学发光,痕量Sn(Ⅳ)对     

巯基葡聚糖凝胶分离富集催化动力学光度法测定痕量锡(Ⅳ)

研究在稀硫酸介质中,以锡(Ⅳ)催化溴酸钾氧化铍试剂Ⅰ的褪色反应及其动力学条件,测定锡(Ⅳ)的范围为0～40μg/L:检测限为1.63×10-8g/L.采用巯基葡聚糖凝胶(SDG)分离富集,使方法的选择性得到了大大的提高,可用于多种样品中痕量锡(Ⅳ)的测定,结果令人满意.     

9-(2-吡啶基)-2,6,7-三羟基萤光酮—十二烷基硫酸钠胶束增敏分光光度法测定微量锡

本文研究了以9-(2-吡啶基)-2,6,7-三羟基萤光酮作显色剂、以阴离子表面活性剂十二烷基硫酸钠作增敏剂的分光光度测定微量锡的新方法。方法具有显色迅速、不用催化剂、灵敏度及选择性较高以及不含乙醇等特点。配合物在536nm处有最大吸收,其表观摩尔吸光系数ε_(536)为1.58×10~5L·mol~(-1)·cm~(-1)。除锆与锗以外,其它金属离子均不干扰锡的测定。方法用于某些合金及钢铁试样的分析,结果满意。     

Determination of trace tin by solid substrate-room temperature phosphorimetry using sodium dodecyl sulfate as sensitizer

The effects of different surfactants on solid substrate-room temperature phosphorescence (SS-RTP) properties of Sn(4+)-morin systems were investigated. It was found that the SS-RTP intensity of luminescence system was increased greatly in presence of sodium dodecyl sulfate (SDS). A new highly sensitive method for the determination of trace tin has been proposed based on sensitization of SDS on SS-RTP intensity of morin-tin system on the filter paper substrate. The linear dynamic range of this method is 8.0-112 ag per spot (with the volume of 0.4 microl per spot) with a detection limit of 4.0 ag per spot, and the regression equation is DeltaIp=199.7+3.456m(Sn(IV)) (ag per spot), with the correlation coefficient r=0.9998 (n=7). This simple, rapid and reproducible method has been applied to determine the amount of tin in real samples with satisfactory results.     

新型鳌合纤维素富集原子吸收测定痕量的铅、镉、铜和镍

本文利用自制的新型吡咯烷二硫代甲酸铵螯合纤维素（CC－APDC），经过最佳条件选择，在同一水样中同时富集和洗脱了铅、镉、铜、和镍。实验结果表明，CC－APDC用于痕量元素的分离富集具有交换速度、易于洗脱、富集倍数大、选择性好等优点。样品使用效果令人满意。     

盐酸-甲醇体系中痕量锡的阳极溶出伏安法测定

极谱分析测定锡,方法简便,但选择性差,无法消除铅干扰,更不能同时测定。在水溶液中,用伏安法测定锡,干扰情况不能改善。等人采用难溶盐形式富集锡,提高了选择性,但重现性差。Kiekens和Debacker等人又提出了一些新底液和电极,但锡、铅相互影响还是存在,而且灵敏度也不高。本文提出在HCl-甲醇体系中,以棒状汞膜电极为工作电极,半微分溶出伏安法测定锡,铅不干扰,并可同时测定,获得较为满意的结果。     

锑精矿中锡的快速测定

报道了大量锑中微量锡的分离方法。在一定的碱量条件下，使锑大部分沉淀，分离后的溶液用水杨基荧酮进行锡的光度法测定。     

氢化物发生—光度分析法连续测定砷锡

锗、砷、锡、锑等性质相近元素在用普通分光光度法测定时,存在着选择性差的问题,为实际分析及连续测定造成了困难。共价氢化物发生-银溶胶光度分析体系的建立和发展,基本解决了此类元素的选择性问题,也为同时或连续测定创造了条件。本文在原工作的基础上,借助于AsH_3和SnH_4在形成酸度上的差异,在高酸度(3.0mol/L HCI)溶液中使砷离子转变为AsH_3逸出分析后,再调节至微酸性(pH 4.5,CH_3COOH-CH_3COONa)产生SnH_4,而显色测定,     

Preconcentration by coprecipitation of arsenic and tin in natural waters with a Ni-pyrrolidine dithiocarbamate complex and their direct determination by solid-sampling atomic-absorption spectrometry

A method for the determination of trace amounts of arsenic and tin in natural waters is described. Trace amounts of arsenic and tin were preconcentrated by coprecipitation with a Ni-ammonium pyrrolidine dithiocarbamate (APDC) complex. The coprecipitates obtained were directly analyzed by graphite-furnace atomic-absorption spectrometry (GFAAS) using the Ni-APDC complex solid-sampling technique. The coprecipitation conditions used for the trace amounts of arsenic and tin in natural water were investigated in detail. It was found that arsenic and tin at sub-ng mL(-1) levels were both coprecipitated quantitatively by Ni(PDC)2 in the pH range 2-3. The concentration factors by coprecipitation reached approximately 40,000 when 2 mg nickel was added as a carrier element to 500 mL of the water sample. The proposed method has been applied to the determination of trace amounts of arsenic and tin in river water and seawater reference materials, and the detection limits for arsenic and tin, which were calculated from three times of the standard deviation of the procedural blanks, are 0.02 ng mL(-1) and 0.04 ng mL(-1), respectively, for 500-mL volumes of water sample.     

荧光染料吖啶红作测定蛋白质的生物探针——蛋白质的染料分析法新进展

简述染料结合分析法的发展过程,吖啶红染料自取和体系测定蛋白质的最佳试验条件和测定结果。阳离子荧光染料吖淀红及其自聚的二聚体的可平衡转化,形成自聚平衡体系,在表面活性剂十二烷基磺酸钠的存在下,蛋白质的定量加入可调节这一平衡,从而引起体系 荧光有规律的变化。方法线性范围宽、灵敏度高、反应速度快、准确度高 、抗干扰 能力强,是染料分析法定量测定蛋白质的最新方法之一。     

脂肪酸萃取锡精矿中微量稀土元素的方法研究

从锡矿石中测定伴生微量元素,主要采用加碘化铵分离锡.卢国仪等人,在两次氢氧化钠熔矿时加入碘化铵灼烧除锡后,完成微量锆的比色测定.由于锡精矿中含锡量高达50％以上,又极易水解,对于微量稀土元素的偶氮肿Ⅲ比色测定有严重干扰.脂肪酸萃取稀土元素已有报道.但用来萃取锡精矿中微量稀土元素未见报道. 本文指出,脂肪酸用来萃取锡矿石中微量稀土元素有很高的选择性,不因多次分离而损失,只需一次萃取分离后,直接进行比色测定.本文研究了在pH4.0～5.5的饱和硝酸     

Study on the interaction among molecules and the determination of DNA by light scattering with a new type rhodanine derivative

In this paper the resonance Rayleigh scattering (RRS) and second-order scattering (SOS) spectrums of interaction between deoxyribonucleic acid (DNA) and 3-(4′-methylphenyl)-5-(2′-sulfophenylazo) rhodanine (4MRASP) in the environment of surface active substance sodium dodecyl sulfate (SDS) were reported. The light scattering intensity of 4MRASP was enhanced obviously and directly proportional to the concentrations of DNA when DNA was present. Based on this, two new determination methods of DNA were established with high sensitivity and selectivity, and the limits of detection were 8.00 and 1.07 ng mL⁻¹. They were applied to the determination of trace amounts of nucleic acid in synthetic and practical samples with satisfactory results. At last, the active mechanism among molecules was studied by ultraviolet spectrum, scattering spectrum and thermodynamics, which showed that the active force was changed from hydrophobic force to electrostatic force before and after SDS was added, and the mechanism of sensitization effect of SDS was proposed.