红外光谱法在纸张分析中的应用

红外光谱法作为一种应用广泛的光谱分析手段,在纸张分析中有重要的应用,其应用范围不断得到拓展,本文综述了红外光谱法在纸张分析中的应用。     

原子荧光光谱法测定土壤中的砷

应用原子荧光光谱法测定砷的含量。以深层生土、地表熟土为样品,采用顺序注射氢化物发生-原子荧光光谱法进行测定。在最佳实验条件下,方法的线性范围在2—60μg/L以内,相关系数r=0.9993,检出限为0.16μg/L,测定标准溶液的RSD为1.6%(n=11),样品加标回收率为96.5%—103.5%,方法简单、快速,可测定土壤中的砷。     

绞股蓝种子中α-桐酸的定性和定量分析

用RTX-5MS弹性石英毛细管柱(0.25mm×30m×0.25μm)气相色谱-质谱法(GC-MS)分析绞股蓝种子中的α-桐酸。用相对保留时间和质谱对α-桐酸进行定性分析,用内标法对α-桐酸进行定量分析。结果表明,绞股蓝种子中含有α-桐酸,在0.34—1.37mg/mL范围内线性关系良好(R2=0.9996),平均回收率为99.91%,且绞股蓝种子中α-桐酸的含量为66.9mg/g。实验结果为以后的绞股蓝种子中α-桐酸的开发与利用提供理论依据。     

维生素B2片中维生素B2的测定及稳定性

以pH=7.0的水作为溶液,激发、发射波长分别为443、523nm,运用荧光光谱法测定了维生素B₂的荧光强度,以荧光强度与浓度的关系作图,得到了回归曲线,本实验条件下,在5×10^-8—6×10^-7g/mL范围内呈良好的线性关系,回收率在98.53%—103.59%之间,该方法具有灵敏度高、重现性和稳定性好的特点,但维生素B₂不稳定。     

微量悬浮液进样-火焰原子吸收光谱法测定霜类化妆品中的铅

基于悬浮液技术处理霜类化妆品样品,将样品悬浮在1.00g/L琼脂溶液中制成均匀的悬浮液,采用微量进样技术建立了火焰原子吸收光谱法快速测定霜类化妆品中的铅。方法的检出限为0.030μg/mL,回收率为98.8%—101.5%。方法应用于实际样品的测定,结果满意。     

流动注射-氢化物发生-原子荧光光谱法测定牛奶中的铅

建立了流动注射-氢化物发生-原子荧光光谱法测定奶制品中铅含量的分析方法,对仪器条件和反应条件进行了选择、优化。方法的检出限为0.30μg/L,相对标准偏差小于4.7%,回收率为90.0%—114.5%,符合食品中痕量元素的分析要求。     

Review of recent advances in the preparation of organic polymer monoliths for liquid chromatography of large molecules

In recent years the use of monolithic polymers in separation science has greatly increased due to the advantages these materials present over particle-based stationary phases, such as their relative ease of preparation and good permeability. For these reasons, these materials present high potential as stationary phases for the separation and purification of large molecules such as proteins, peptides, nucleic acids and cells. An example of this is the wide range of commercial available polymer-based monolithic columns now present in the market.     

A Comparison Of Measurement of Homovanillic Acid in Brain Tissue by Gas Chromatography Mass Spectrometry and Liquid Chromatography with Electrochemical Detection

Abstract

A comparison of liquid chromatography with electrochemical detection (LCEC) and gas chromatography mass spectrometry (GCMS) has been made for analysis of homovanillic acid (HVA) in rat brain tissue. The LCEC procedure gave slightly higher average values of HVA in the samples measured; however, the HVA content determined by both methods related significantly. Rat brain meostriatum was used as representative samples for comparison of the two analytical procedures.     

The Analysis of Galvanizing Preflux Solutions for Zinc by Flow Injection-Flame Atomic Absorption Spectrometry

Abstract

A direct flow injection flame atomic absorption spectrometry method of determining zinc salt solutions with concentrations of 100's g dm^?3 is reported. It was shown that high concentrations of KCl, NaCl and NH₄Cl do not significantly interfere with the determination of zinc in both the mg dm^?3 and g dm^?3 concentration ranges. Where g dm^?3 concentrations were determined a secondary spectral line at 307.6 nm was found satisfactory. Galvanizing preflux solutions were analyzed both after dilution to the mg dm^?3 range at 213.9 nm and directly injected at 307.6 nm. Precisions of better than 6.6% rsd were observed by the direct method compared with better than 4.8 by dilution techniques. Concentrations up to 110 g dm^?3 in zinc were determined the total salt content being greater than 300 g dm^?3.     

ICP-AES and Colorimetry as Analytical Tools for the Determination of Phosphorus Containing Compounds,Including Phosphine

Abstract

The direct quantitative determination of phosphine in gaseous mixtures or in air samples is associated with a number of difficulties. the paper describes an alternative technique based on the oxidation of phosphine to phosphate. Phosphate can be analysed either by inductively coupled plasma-atomic emission spectrometry (ICP-AES) or by a colometric method.

Because the problem of a proper (quantitative) sampling of phosphine in the air of working environments and/or in gaseous mixtures is still unsolved, standard solutions of KH₂PO₄ have been used as analytes (“artifical samples”) in the ICP-AES method.

The statistics concerning the sample variances, obtained from the 2 methods mentioned above, indicate no differences.