电热蒸发进样微波诱导等离子体原子吸收光谱法测定银和镉的研究

研究了以常压低功率氩微波诱导等离子体（ＭＩＰ）为原子化器的原子吸收光谱法（ＡＡＳ）测定银和镉。采用电热蒸发（ＥＴＶ）,浓Ｈ２ＳＯ４吸收去溶的进样方法。考察了微波前向功率,载气流量,去溶电压,去溶时间,蒸发电压,酸度对银,镉测定的影响。方法已用于试样分析。     

微波等离子体炬发射光谱法去溶系统性能的研究

用微波等离子体矩（MPT）作激发光源，等离子体的工作气体为氩气，研究了气动雾化进样去溶系统的工作参数对分析性能的影响，探讨了水冷凝与浓硫酸吸收二者协同去溶的相关性，结果表明，OH （Q1带，带头谱线为308.520nm）的发射强度即可判别样品去溶效果。     

用于MIP-AES的气动雾化法的研究

水溶液样品经气动雾化后引入低功率微波诱导等离子体, 由于采用了新的去溶系统和分离器, 大大改进了微波诱导等离子体原子发射光谱法的光谱分析性能。详细考察了各实验参数对测定一些元素的影响。这些元素的检出限和测定精密度令人满意。     

用微波诱导等离子体发射光谱法测定铁及其它一些元素

水溶液样品用超声雾化法雾化经加热后用常规冷凝器和浓H_2SO_4吸收法去溶,然后引入微波等离子体。详细考察了载气流量、微波功率和HCl浓度等实验条件的影响和KCl对谱线的增强作用。测定了一些地质样品中的铁,得到了满意的结果。     

秸秆中钾的溶出工艺研究

采用单因素实验法考查了微波功率、固液比、消解时间等条件对钾溶出率的影响。优化得出较适钾的溶出工艺条件:微波功率为中高火,液固比35,消解时间60 s,在此条件下,微波溶出钾量为秸秆量的3.057%。     

用常压MIP作原子吸收光谱法原子化器的研究

本文研究了用常压微波诱导等离子体作为原子吸收光谱法的原子化器的可行性, 采用电热蒸发浓硫酸去溶微量进行装置进样, 详细考察了各种实验参数对测定铜的影响。实验证明测定Cu、Ag、Pb的特征浓度分别为0.04、0.04、0.1μg/ml。     

基于生命周期评价技术研究全铁含量测定对环境的影响

利用生命周期评价软件Sima Pro7和环境影响评价模型IMPACT 2002+,通过对化学分析方法的清单分析及计算,评价和比较了3种测定铁矿中全铁含量的化学分析方法(酸溶法、碱熔法、微波消解法)对人类健康、生态质量、气候变化及资源消耗等的影响。发现3个方法对环境的影响主要集中于人类健康危害、气候变化和资源消耗方面。通过计算3种方法的生命周期单一环境负荷值,发现碱熔法、酸溶法和微波消解法的单一环境负荷值分别为1.97,1.81,0.07 m Pt,对环境总体的影响,碱熔法和酸溶法分别为微波消解法的28倍和26倍。单独对人类健康危害指标而言,碱熔法为1.15 m Pt,酸溶法为1.07 m Pt,微波消解法仅为0.039 6 m Pt。碱熔法、酸溶法和微波消解法的碳足迹分别为5.12,4.62,0.189 kg CO_2eq。说明微波消解法排放量最小,其环境友好性最佳,值得推荐。     

超声雾化进样微波诱导等离子体原子吸收光谱法测定银的某些影响因素研究

本文将超声雾化技术与MIP-AAS联用,以“L”型吸收管代替“T”型吸收管作为AAS测量的吸收池,采用水冷凝和浓H_2SO_4吸收相结合去溶,研究TUSN-MIP-AAS方法测银时的某些影响因素,讨论了微波前向功率,载气流速、去溶系统、溶液酸度、共存离子及易也离元素等对吸收信号的影响,本法所得的测银的特征浓度为0.01μg/ml(328.1nm)和0.03μg/ml(338.3nm),相对标准偏差为7.5％.     

一种实用的微波砂浴溶样装置

湿法难溶试样的分解常用熔融法。但使用现行的高温马弗炉加热 ,不仅费时 ,而且耗能 ,效率和效益都不令人满意[1] 。微波辐射溶 (熔 )样异常快捷 ,但在家用微波炉内直接分解试样 ,极易损坏微波炉的磁控管 ;用聚四氟乙烯容器密闭溶样时 ,常会有爆炸的危险。本文根据微波辐射的特点和难溶试样的性质 ,设计出一种简易安全的微波砂浴熔样装置 ,它是基于砂盘中的石墨炭会强烈吸收微波能致热坩埚中的内容物 ,促使试样在数分钟内熔融分解 ,而特设的假负载能将反射回来的微波能充分吸收 ,从而起到保护微波炉磁控管的作用 ,试验证明 ,这种设想是可行的…     

超声雾化进样微波诱导等离子体原子发射光谱法测定痕量磷的研究

本文提出了一种测定水溶液样品中痕量磷的微波诱导等离子体原子发射光谱法(MIPAES)。样品经超声雾化并去溶后引入等离子体。考查了Ar和He MIP中磷的发射光谱特性和一些实验参数对磷发射强度的影响。用Ar和He作工作气体时,检出限分别为0.03和0.0045μg/ml,方法的相对标准偏差小于5％。     

Iodine Determination by Microwave Plasma Torch Atomic Emission Spectrometer Coupled with Online Preconcentration Vapor Generation Technique

This article focuses on iodine determination by microwave plasma torch atomic emission spectrometry （MPT-AES） coupled with online preconcentration vapor generation method. A new desolvation device, multistrand Nafion dryer, was used as the substitute for condenser desolvation system. Some experimental conditions, such as preconcentration time, acidity of sample solution, rinsing solution acidity and dynamic linear range were investigated and optimized. The new desolvation system eliminates the problem of decreasing emission intensity of I（I） 206.238 nm line with the increase of working time on a conventional condenser desolvation system, thus greatly improving the reproducibility.     

Desolvation of acid solutions in inductively coupled plasma atomic emission spectrometry by infrared radiation. Comparison with a system based on microwave radiation

The behaviour of an infrared desolvation system with acid solutions in inductively coupled plasma atomic emission spectrometry (ICP-AES) is evaluated, and the influence of the liquid uptake rate and of the nature and concentration of the acid on the solvent and analyte transport rates and on the analytical figures of merit is studied. The results are compared with those obtained with a desolvation system based on the absorption of microwave radiation. The infrared desolvation system performs best at low sample uptake rates (0.4 ml min⁻¹) and its behaviour strongly depends on the nature and concentration of the solution used. With nitric and hydrochloric solutions, there is almost no effect of the acid concentration on the emission intensity, while for sulfuric and perchloric acids the signal decreases as the acid concentration is increased. These effects seem to be related with the different capability of the acid aerosols to be heated in an IR field. The microwave desolvation system seems to be more prone to matrix (acid) effects, specially when using sulfuric and perchloric acids, resulting in emission intensities which are usually lower than those obtained with the infrared desolvation system, though their limits of detection are quite similar.     

Direct determination of trace amounts of sodium in water-soluble organic pharmaceuticals by microwave induced plasma atomic emission spectrometry

The direct determination of trace sodium by microwave induced plasma atomic emission spectrometry (MIP-AES) in water-soluble organic substances utilized in pharmaceutical preparations was developed. No decomposition of the organic constituents was required. Samples were dissolved with water and introduced to the plasma after ultrasonic nebulization without desolvation. A limit of detection (3sigma) of 0.91-3.0 ng ml(-1) was obtained under experimental conditions. The quantitative MIP-AES procedure involved the standard addition method. The sodium content determined in reference material NIST SRM 1568A Rice Flour agreed with the certified value (6.6+/-0.8 mug g(-1)). Physical and chemical interferences were investigated. It was found for the microwave plasma that it is possible to introduce organic substances solutions of concentration up to 5% without sensitivity losses. This direct technique is fast and sensitive and helps to reduce contamination connected with the sample preparation procedure.     

Microwave-assisted synthesis of substituted fluoroazines using KF·2H2O

This Letter describes a new microwave-assisted fluorination of azines using hydrated potassium fluoride in untreated DMSO under atmospheric conditions. It is thought that microwave irradiation promotes desolvation of the fluorine anion leading to halide nucleophilic substitution.     

静电和疏水效应对SARS冠状病毒3CL蛋白酶二聚体稳定性的影响

从TGEV3CL蛋白酶二聚体结构出发,研究了TGEV3CL蛋白酶二聚体单体之间的静电和疏水相互作用.蛋白质的静电相互作用通过有限差分方法求解Poisson-Boltzmann方程得到,疏水相互作用通过分析溶剂可及性表面模型得到.考察了不同pH值对SARS3CL蛋白酶二聚体静电和疏水相互作用的影响,在pH=5.5～8.5时,二聚体静电相互作用能、静电去溶剂化能和疏水自由能都具有较小的数值,表明在该条件下静电和疏水相互作用有利于二聚体的稳定存在.由于SARS3CL蛋白酶活性模式为二聚体,因此,在该pH值范围内,有利于蛋白酶保持活性.在pH=7.0条件下,蛋白酶单体之间具有最强的静电和疏水相互作用,从而使蛋白酶具有最强的活性,这与实验结果相一致.pH值对静电去溶剂化能的影响大于疏水自由能,表明静电作用是造成强酸或强碱条件下二聚体不能稳定存在的主要原因.