四氟化硅气体中杂质的检测及净化研究进展

介绍了四氟化硅气体中杂质的4种检测方法:气相色谱法、红外光谱法、气相色谱质谱法、原子发射光谱法。其中,气相色谱法一般用来测定四氟化硅气体中的烃类杂质,红外光谱法主要用来测定四氟化硅气体中的氟硅烷、氟氧硅烷、氟硅醇杂质。气相色谱质谱法用来测定四氟化硅气体中的六氟化硫杂质,原子发射光谱法主要用来测定四氟化硅气体中的金属杂质。然后对四氟化硅气体的不同净化方法进行列举,并对净化工艺的条件、优缺点进行了阐述。     

四氟化硅气体中杂质的检测方法

介绍了四氟化硅气体中几类杂质的检测方法,主要包括气相色谱法、傅里叶变换红外光谱法、质谱法和微波波谱法。用气相色谱仪可以检测出四氟化硅中气体中C1~C4碳氢化合物;用高分辨率傅里叶变换红外光谱仪可以检测出SiF3OH,HF,SiF3H,SiF2H2,SiH3F,CO2,CO等气体杂质;用微波波谱仪可以检测出四氟化硅中CHF3,CH2F2,CH3F等气体杂质;用质谱仪可以检测出四氟化硅中SiF3H,SiF2H2,SiF3OSiF3等气体杂质。通过对比得出每种检测方法的优点和缺点。     

双氦离子化气相色谱仪分析四氟化硅气体中微量杂质

介绍了一种利用双通道氦离子化气相色谱仪(PDHID),分析四氟化硅中微量硅烷、磷烷、氟代烷、C2～C3碳氢化合物以及常见气体杂质的方法.由于四氟化硅具有很强的腐蚀性,在对其进行分析时,利用阀切割系统将大量的四氟化硅主要成分切割,及时地将四氟化硅反吹出去,使其不进入检测器系统.经过将四氟化硅气体进样检测验证,该方法能够有效测定四氟化硅气体中多种微量杂质.     

特殊电子气-四氟化硅分析检测

四氟化硅是一种重要的特殊电子气体,可用于电子和半导体行业,高纯度的四氟化硅还可作为非晶体硅、硅烷、多晶体硅、光纤等制备的原料,文章介绍了四氟化硅气体中气体杂质、金属杂质及碘的分析检测方法,初步确定了四氟化硅气体中的杂质分析。     

SiF_4气体中(SiF_3)_2O的净化方法

高纯度四氟化硅(SiF4)是电子工业中的一种重要原料,能用于光导纤维、太阳能电池和水泥硬化剂等的原料。详细介绍了SiF4气体中(SiF3)2O的生成原理和(SiF3)2O的净化方法,六氟二甲硅醚的纯化方法有活性炭吸附法,与含氟化氢的浓硫酸,氟气,氟化剂等物质发生反应,其中详细介绍了活性炭对四氟化硅气体中的杂质的净化效果。     

高纯SiF_4气体中杂质的定量分析方法研究

高纯度四氟化硅(SiF4)是新型硅烷法制备多晶硅的一种重要原料,其纯度影响硅烷及多晶硅的纯度及用途。本文对国内外市场上SiF4产品质量做了对比分析,并对以氟硅酸为原料生产SiF4气体中:含氧氟硅化合物、碳氢化合物、氟化氢、金属元素、碘等杂质提出定量分析方法。为国内生产高端的SiF4产品检测提供帮助。     

2020年将实施的28项仪器分析类国家标准

正近日,国家市场监管总局、国家标准化管理委员会批准发布了501项国家标准和6项国家标准修改单,其中382项为新制定的标准。新发布的507项标准中有28项涉及仪器分析方法,包括原子荧光光谱法、火焰原子吸收光谱法、石墨炉原子吸收光谱法、冷原子吸收光谱法、分光光度法、红外线吸收法、液相色谱-质谱联用法、气相色谱-质谱法、离子色谱法、电感耦合等离子体发射光谱(ICP-OES)法、测汞仪法等,涉及仪器分析方法的28项标准详     

微量镍的检测方法

评述了微量镍的检测方法,包括分光光度法、原子吸收光谱法、原子发射光谱法、等离子体质谱法、电化学法、液相色谱法、离子色谱法、X射线荧光光谱法等,并展望了其发展前景。     

墨粉的结构及鉴别方法研究进展

本研究通过分析墨粉的结构、了解墨粉的基本组成,并着重介绍利用X射线衍射法、等离子发射光谱法、傅立叶红外光谱法、扫描电镜能谱联用法、裂解气相色谱法对不同厂家不同型号墨粉鉴别的研究进展。并总结出傅立叶红外光谱法与裂解气相色谱法为墨粉鉴别的重要方法。     

水体中氟的检测与治理研究进展

阐述了氟与人体健康的关系；介绍了离子选择电极法、离子色谱法、气相色谱法、高效液相色谱法、原子吸收光谱法、原子发射光谱法、荧光法、分光光度法等水中氟离子的检测方法;并对化学沉淀法、絮凝沉淀法、吸附法等水中氟离子的去除方法进行了综述.     

佛山市顺德新城区降水中污染物的监测和分析

为掌握佛山市顺德新城区降水中污染物的情况,2015年7月至8月,文章作者分别在雨天进行了降水取样,对降水中的pH、电导率、常见阴离子(F-、Cl~-、NO_3~(2-)、SO_4~(2-))及部分重金属(铅和镉)进行监测分析。选择有相关数据的珠江三角洲和石家庄、厦门等地的降水中污染物的情况进行对比。结果表明,顺德新城区降水中的p H和部分阴离子浓度优于珠江三角洲平均值,酸雨类型属于硫酸和硝酸混合型;其水体洁净程度略差于石家庄;铅和镉的浓度也高于厦门,甚至部分超出了人体能直接接触的安全范围。     

Metabolism of trideuterated iso-lignoceric acid in rats in Vivo and in human fibroblasts in culture

Saturated very long chain fatty acids (fatty acids with greater than 22 carbon atoms; VLCFA) accumulate in peroxisomal disorders, but there is little information on their turnover in patients. To determine the suitability of using stable isotope-labeled VLCFA in patients with these disorders, the metabolism of 22-methyl[23,23,23-²H₃]tricosanoic (iso-lignoceric) acid was studied in rats in vivo and in human skin fibroblasts in culture. The deuterated iso-VLCFA was degraded to the corresponding 16- and 18-carbon iso-fatty acids by rats in vivo and by normal human skin fibroblasts in culture, but there was little or no degradation in peroxisome-deficient (Zellweger’s syndrome) fibroblasts, indicating that its oxidation was peroxisomal. Neither the 14-, 20-, and 22-carbon iso-fatty acids nor the corresponding odd-chain metabolites could be detected. In the rat, the organ containing most of the iso-lignoceric acid, and its breakdown products, was the liver, whereas negligible amounts were detected in the brain, suggesting that little of the fatty acid crossed the blood-brain barrier. Our data indicate that VLCFA labeled with deuterium at the ω-position of the carbon chain are suitable derivatives for the in vivo investigation of patients with defects in peroxisomal β-oxidation because they are metabolized by the same pathways as the corresponding n-VLCFA. Moreover, as iso-VLCFA and their β-oxidation products are readily separated from the corresponding n-fatty acids by normal chromatographic procedures, the turnover of VLCFA can be more precisely measured. A preliminary report of part of this work (Reference 18) was presented at the 5th International Symposium on the Synthesis and Applications of Isotopes and Isotopically Labelled Compounds, Strasbourg, France, June 20–24, 1994.     

高效液相色谱法分析化妆品中微量成分的研究进展

综述了高效液相色谱法在化妆品中防腐剂、防晒剂中紫外线吸收剂以及性激素的检测等几个方面的应用;同时,介绍了分析所用的色谱柱、流动相、使用的检测手段以及样品的提取方法;最后针对目前存在的问题,提出了高效液相色谱用于化妆品中微量成分分析的研究方向和发展前景。     

Denitrification in shallow groundwater in a coastal agricultural area in Japan

In a coastal agricultural area in the central part of Japan (Shizuoka), we found decreasing nitrate concentration with depth in a shallow groundwater, where the depth to water table varied between 0.6 and 1.2 m below ground surface. High nitrate concentrations (5–29 mg N L^–1) were often observed in the upper layer (0–2 m) of the groundwater, but the concentration decreased to less than 1 mg N L^–1 in the deeper layer. Ammonium was scarcely detected, and the concentration of dissolved oxygen was usually low (< 1 mgO₂ L^–1) in the groundwater. Nitrate in the groundwater often had very heavy nitrogen stable isotope ratios (>20{}). There was a negative relationship between nitrogen stable isotope ratio of nitrate and its concentration. When nitrate was injected into the groundwater with acetylene and bromide (a conservative tracer), nitrate concentration decreased to 20% of the initial level within 5 days, accompanied by the increase in nitrite and nitrous oxide concentration and a little change in bromide concentration. These results indicate that microbial denitrification plays a potential role in the decrease of nitrate in shallow groundwater at the study site.     

我国硝酸工业生产技术新进展

系统叙述了我国硝酸工业2000-2007年生产现状及主要技术成果,尤其指出了国产"四合一"机组的成功投运,使我国硝酸国产化装置取得较大的进步,表现在吨酸的铂耗、氨耗和能耗等方面接近国外引进装置水平,同时介绍了国外双加压法硝酸生产技术的进展.我国已成为硝酸生产大国,仍需以先进的技术改造和发展我国硝酸工业,确保我国硝酸工业健康有序地发展,加快从硝酸生产大国向强国迈进的步伐.