吸附/热脱附气相色谱分析痕量C1～C5烃

本文以活性炭、TDX-01、Tenax GC、Porapak Q和GDX-104为吸附剂，不经冷凝，在常温下吸附富集痕量C1～C5烃并直接引入毛细管柱。同时探讨了吸附剂的最佳热脱附温度、饱和吸附量、吸附富集回收率、热脱附直接进样的线性规律及方法的相对偏差．     

Trace Elemental Analysis of Allium Species by Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) with Multivariate Chemometrics

Aerial parts and roots of the 12 Allium species collected from five localities of Turkey were studied for trace elements (Ag, As, Cd, Co, Cr, Cu, Ni, Pb, Se, Tl, V, and Zn) using inductively coupled plasma mass spectrometry (ICP-MS). A tomato leaves certified reference material was used to characterize the accuracy and precision of the analysis. Each Allium species contained Se (315–2740?µg/kg), Tl (2.75–71?µg/kg), V (77–6790?µg/kg), and Zn (3.73–26.6?mg/kg) which can meet the necessary daily intake of these minerals. In addition, chemometric analyses were performed using correlation analysis, principal component analysis, and hierarchical cluster analysis to determine the association of 12 trace elements in the Allium species. Using chemometrics, the distribution of elements between aerial parts and roots, and geographic collection localities of Allium species were also examined. This study is important the consumers because of the wide consumption of Allium species. This report is the first detailed characterization of the metal content of Allium species.     

On the effect of trace impurities at the air/water- and the mercury/water interface

An aqueous solution of 1 10^–4 Mn-octanoic acid containing 0.005 M hydrochloric acid and 0.1 M sodium chloride was used to demonstrate the influence of surface-active trace impurities on the air/water- and the mercury/water interface. The solution was purified stepwise to obtain states of successively growing surface-chemical purity. The effect of contamination at the air/water- and the mercury/water interface was followed simultaneously by monitoring the dynamic surface tension in the case of ad- and desorption and the differential capacity, respectively, at various stages of purity. The results give evidence that the effect of trace impurities at the air/solution surface is as important as at the mercury/solution interface.     

气提法富集气相色谱／质谱法测定水中痕量挥发有机物

作者改进了气提法富集水中痕量挥发性有机物装置。研究了实验条件对水中痕量有机物富集的影响，并确定了最佳富集条件。以气提法富集气相色谱／质谱法（ＧＣ／ＭＳ）测定了水样中痕量挥发性有机物，取得了满意的结果。     

Direct Analysis of Beer by ICP-AES: A Very Simple Method for the Determination of Cu, Mn and Fe

A very simple method for determination of trace amount of Cu, Mn and Fe in beer by inductively coupled plasma spectrometry (ICP-AES) was developed. The beer was directly introduced into the plasma, without dilution or adding of reagents, via a conventional V-groove nebulizer. The only sample preparation used was degassing of the beer to remove CO₂. By optimizing the ICP-AES parameters (RF power and Nebulizer gas flow rate) and by the appropriate choice of wavelengths for measurements, sufficient accuracy for the determination of the trace metals was obtained. Various types of beers were analysed by the direct ICP-AES method and for comparison, also with two other methods: by GFAAS and ICP-AES after decomposition. No significant difference was found for Cu and Mn (ANOVA, 95% confidence level) using the three methods. This was normally also the case for Fe; only in one case did the result of Fe by the direct method deviate from the other methods (10% lower results). The limit of detection for the direct method was estimated to 1.1, 0.3, and 1.1 ng mL⁻¹ for Cu, Mn, and Fe, respectively.     

微量元素与高血压Ⅱ.微量元素在血压调控中的作用及机制

综述了微量元素在血压调节中的可能作用及机制。内容包括：血压的神经及体液调节、对血压可能有影响的微量元素、血压的元素调节，以及15种元素在人类血压调节中的可能作用。附2图、7表、36篇参考文献。     

Evaluation of uncertainty sources associated with toxic trace element concentrations in rice

Todays and tomorrows globalized world requires the acceptance of each others capabilities, competence and metrological traceability of measurements to the International System of Units and thus mutual acceptance of quantitative results. Therefore, mutually and publicly recognized standards and certificates are needed at national and international levels. An important step to attain this ambitious goal is to intensify regional metrological collaboration. The exercises of interlaboratorial comparisons are important as part of a system to guaranty the quality of analysis. To estimate the sources of uncertainty associated with the determination of toxic trace element concentrations in rice and to perform an interlaboratorial comparison, a sample containing cadmium, copper, lead and zinc was distributed to four Brazilian laboratories. The laboratories used atomic emission spectroscopy, graphite furnace atomic absorption spectroscopy and flame atomic absorption spectroscopy. The evaluation of the results provided by the laboratories was made by statistical and graphical methods comparing the results of each laboratory to the certified value.     

Trace analysis of toxic metals,III. Determination of chromium as trivalent chromium by differential pulse polarography

Methods for trace analysis of chromium as Cr³⁺ were investigated, using differential pulse polarography in various media. Determination at the ng/ml-g/ml range can be carried out in KCl/HCl, KCNS/HOAc, and other media. Total concentration of chromium in a solution containing Cr³⁺ and HCrO ₄ ^– can be determined in KCNS/HOAc, and it is found that HCrO ₄ ^– can be converted quantitatively to Cr³⁺. The relative quantity of HCrO ₄ ^– and Cr³⁺ can be determined by the difference between the total chromium concentration and the concentration of HCrO ₄ ^– . The sensitivity (12.5 ng/ml) and accuracy of this method is better than the method that determines total chromium as HCrO ₄ ^– .     

Routine catalytic determination of trace amounts of cobalt in small urine samples

The oxidation of catechol by hydrogen peroxide, catalyzed by cobalt(II), is a highly sensitive and selective reaction. It makes it possible to analyze a small sample of urine (5.0 ml) for cobalt without the need for isolation of the analyte from the matrix. The sample is dried and dry-ashed according to a temperature programme, and the residue is dissolved in hydrochloric acid. After filtration of the solution, acetate buffer and sodium citrate are added and cobalt is determined catalytically in an aliquot of the solution, by the standard-addition method.     

六种祛风湿中成药中微量元素含量的测定

中药功效与微量元素之间的关系 ,已被越来越多的学者研究证实[1～ 3] ,但对祛风湿中成药中微量元素的分析未见报道。现代医学中 ,风湿病是指与免疫代谢、感染、遗传、退行性变有关的骨、关节、肌肉疼痛为主的疾患 ,其范围相当广泛 ,为临床常见病[4] 。本文通过对风湿马钱片等 6种祛风湿中成药中Ｚｎ、Ｆｅ、Ｃｕ、Ｍｎ、Ｓｅ、Ｐｂ、Ｈｇ等 7种微量元素含量的测定 ,为进一步研究相关微量元素的存在形态、探讨药理机制、提高药效和降低毒副作用提供参考。1　实验1 1　仪器与试剂ＷＦＸ ⅠＣ型原子吸收分光光度计 (北京第二分析仪器厂 ) ,Ｗ…