固体无机样品的激光等离子体质谱分析

激光等离子体质谱是一种新颖的质谱分析手段，具有灵敏度高、分析速度快、分析范围广、分析结果准确性高等优点。本文介绍了在自制的激光等离子体源飞行时间质谱计上，有关催化剂、铝箔、活性碳、岩石等固体无机样品的质谱分析结果，显示了激光等离子体质谱的优越性与广泛的应用价值。

无机固体样品中硫的测定方法的研究进展

综述了无机固体样品中硫的高温燃烧热解(包括燃烧-红外吸收法、燃烧-碘量法、燃烧-库仑滴定法、燃烧-中和滴定法和燃烧-电导法等)、湿法消解(包括硫酸钡重量法、硫酸钡比浊法、电感耦合等离子体原子发射光谱法、电感耦合等离子体质谱法、原子吸收光谱法和离子色谱法等)和固体样品直接分析(包括火花源原子发射光谱法、辉光放电原子发射光谱法、X射线荧光光谱法等)等3类测定方法的研究进展(引用文献117篇)。

高频感应燃烧-红外吸收光谱法在测定无机非金属样品中碳、硫的应用

综述了高频感应燃烧-红外吸收光谱法在测定无机固体化学品(固体氧化物和无机盐)、金属矿物、岩石、土壤、尘、煤、碳素材料、石墨矿、硅酸盐、耐火材料、固体催化剂等无机非金属样品中碳、硫元素的应用,侧重汇总了称样量、助熔剂的用量及加入顺序、标准样品等主要分析条件,并展望了该法的应用前景和发展方向(引用文献156篇)。

无机固体样品中碳的分析方法综述

本文综述了高温燃烧-红外吸收法、气体容量法、碱石棉吸收重量法、库仑滴定法、非水滴定法、火花源-原子发射光谱法、辉光放电-发射光谱法、激光诱导激发光谱、X射线荧光光谱法、X射线光电子能谱法等分析方法在金属合金、环境地质样品、无机非金属材料等无机固体样品碳含量分析中的应用现状。讨论了碳分量分离与分析的常规流程与方法。

常用样品前处理设备的发展与展望

强调了样品前处理在分析化学中的地位,并介绍常用有机样品前处理流程涉及到提取、浓缩、净化等技术,常用无机样品前处理过程涉及到消解、灰化、熔融等技术,进一步阐述了这些技术的原理以及如何发展衍化为自动化设备。对国内外前处理设备发展状况进行了剖析,认为样品前处理设备这一细分行业,目前处于市场成长期,发展潜力巨大。最后,本文作者展望了前处理设备的发展趋势。

农用地土壤污染详查样品采集与制备工作要点

针对农用地土壤污染详查样品采集要点展开分析,内容包括划分样品采集区域、合理选择采集方法、现场记录及拍照等,结合制样场地预处理、合理选择工具、筛选样品制备方法等制备工作要点,研究做好仪器设备选择、采集人员合理选择、做好样品流转工作、明确样品管理制度等内容,从而提升采集样品的合理性,提高分析结果的可靠性。

Effect of sample treatment on determination of arsenic （Ⅲ） and arsenic （Ⅴ） in aqueous and tissue samples by hydride generation atomic absorption spectrometry

The purpose of this procedure was to optimize and improve a method that used for the determination of arsenic （Ⅲ） and arsenic （Ⅴ） in biological and environmental samples. The method is based on hydride generation and atomic absorption spectrometry. For both As （Ⅲ） and As （Ⅴ） the parameters such as NaBH4, HCI concentration, and pH were optimized. Absorption signal of As （Ⅴ） was approximately 17% of As （Ⅲ） signal. Therefore, for estimation of As （Ⅲ） and As （Ⅴ） concentrations in various samples the difference between the absorbance obtained for arsenic, without and with previous treatment of samples with potassium iodide （KI）, can be applied. The calibration graphs were linear （r〉0.99）, and the detection limits of the method based on three times the standard deviation of the blank were 0.14 and 0.64 μL^-1 for As （Ⅲ） and As （Ⅴ）, respectively. The relative standard deviation （R.S.D.） of measurements was less than 10%. As a means of checking performance method, water samples were spiked with known concentrations of both As （Ⅲ） and As （Ⅴ）, and recovery above 94% was obtained. The proposed method was applied successfully to determine inorganic As （Ⅲ） and As （Ⅴ） in various environmental and total As in biological samples.

The effect of different deformation mechanisms on the chemical structure of anthracite coals

To study the effect of different deformation mechanisms on the chemical structure of anthracite coals and further understand the correlation between changed chemical structures and coal and gas outburst, ten groups of sub-high-temperature and sub-high-pressure deformation experiments were performed. All samples maintained primary structure, which were collected from the Qudi Mine in the southern Qinshui Basin of China. The samples were analyzed by ultimate analysis, Vitrinite Reflection(VR), Fourier Transform Infrared spectroscopy(FTIR), and Raman spectroscopy both before and after deformation experiments for contrasting. The results showed that the VR values of all samples after experiments were significantly higher than before experiments, which suggested that the metamorphism degree of anthracite coals was increased by deformation. The results also indicated that both temperature and strain rate had significant effects on the chemical structure of anthracite coals. At a high strain rate of 4×10?5 s?1, the deformation of the samples was mainly brittle in which the mechanical energy was transformed mainly into frictional energy. In this situation, all samples developed several distinct fractured surfaces and the change of chemical structures was not obvious. On the contrary, with the decrease of the strain rates, the ductile deformation was dominated and the mechanical energy was mainly transformed into strain energy, resulting in the accumulation of deformation energy confessed by increasing quantity of dislocation and creep in the coal's interior nucleus. The absorption in the aromatic ring groups increased; otherwise the absorption in the aliphatic structures and ether oxygen groups decreased rapidly. During these experiments, CO was collected from two experimental samples. The number of aromatic rings and the structure defects within the two generated gas samples increased and the degree of molecular structure orders decreased.

Evaluating Loss-on-Ignition Method for Determinations of Soil Organic and Inorganic Carbon in Arid Soils of Northwestern China

There is a need for determinations of soil organic carbon (SOC) and inorganic carbon (SIC) due to increasing interest in soil carbon sequestration. Two sets of soil samples were collected separately from the Yanqi Basin of northwest China to evaluate loss-on-ignition (LOI) method for estimating SOC and SIC in arid soils through determining SOC using an element analyzer, a modified Walkley-Black method and a LOI method with combustion at 375℃ for 17 h and determining SIC using a pressure calcimeter method and a LOI procedure estimated by a weight loss between 375 to 800℃. Our results indicated that the Walkley-Black method provided 99%recovery of SOC for the arid soils tested. There were strong linear relationships(r > 0.93, P < 0.001) for both SOC and SIC between the traditional method and the LOI technique. One set of soil samples was used to develop relationships between LOI and SOC(by the Walkley-Black method), and between LOI and SIC(by the pressure calcimeter method), and the other set of soil samples was used to evaluate the derived equations by comparing predicted SOC and SIC with measured values. The mean absolute errors were small for both SOC (1.7 g C kg-1) and SIC(1.22 g C kg-1), demonstrating that the LOI method was reliable and could provide accurate estimates of SOC and SIC for arid soils.

Dissolved Organic Nitrogen in Mediterranean Ecosystems

Dissolved organic nitrogen （DON） in soils has recently gained increasing interest because it may be both a direct N source for plants and the dominant available N form in nutrient-poor soils, however, its prevalence in Mediterranean ecosystems remains unclear. The aims of this study were to i） estimate soil DON in a wide set of Mediterranean ecosystems and compare this levels with those for other ecosystems; ii） describe temporal changes in DON and dissolved inorganic nitrogen （DIN） forms （NH＋ and NO3）, and characterize spatial heterogeneity within plant communities; and iii） study the relative proportion of soil DON and DIN forms as a test of Schimel and Bennett＇s hypothesis that the prevalence of different N forms follows a gradient of nutrient availability. The study was carried out in eleven plant communities chosen to represent a wide spectrum of Mediterranean vegetation types, ranging from early to late successional status. DON concentrations in the studied Mediterranean plant communities （0-18.2 mg N kg-1） were consistently lower than those found in the literature for other ecosystems. We found high temporal and spatial variability in soil DON for all plant communities. As predicted by the Schimel and Bennett model for nutrient-poor ecosystems, DON dominance over ammonium and nitrate was observed for most plant communities in winter and spring soil samples. However, mineral-N dominated over DON in summer and autumn. Thus, soil water content may have an important effect on DON versus mineral N dominance in Mediterranean ecosystems