胆石中无机元素的定量分析

由等离子体发射光谱分析得知,胆结石中含有多量的Ca和少量的K、Na、Mg、Fe、Mn、Cu、Pb、Si、P、Al、Ti、Cd等元素。在一般情况下,结石样品量少,部分元素含量低,这就要求选用的测试方法具有高的灵敏度并能连续测定。在这方面,原子吸收光谱法显示了它的优越性。本文介绍了在同一份称样中,测定Ca、Mg、K、Na、Fe、Mn、Pb、Cu、Zn、Cd等10种元素的方法。由于采用了混合配位剂——萃取测定,Fe、Mn、Cu等元素能在同一有机相中同时测定,从而简化了分析手续,且具有快速、灵敏的特点,适于批量胆结石样品的分析。     

电感耦合等离子体质谱法测定镁合金中的多种元素

用电感耦合等离子体质谱(ICP-MS)法测定了镁合金中的Be、Al、Ca、Fe、Mn、Ni、Cu、Zn、Ag、Cd、Sn、La、Ce、Pb14种元素,进行了稳定性实验以及Cu、Zn、Ni、Mg、Al基体实验,考察了共存元素的干扰.镁合金标准物质测定值与参考值符合较好,方法检出限为0.0002～0.3346 μg/g,相对标准偏差RSD＜10%.     

电感耦合等离子体质谱法(ICP-MS)同时测定正山小种红茶中18种微量元素

采用微波消解样品,应用电感耦合等离子体质谱法(ICP-MS)同时测定正山小种红茶中Na、Mg、K、Ca、Fe、Al、Zn、Mn、Cu、Ge、Cd、Cr、Ni、Se、Mo、Hg、As和Pb 18种元素。对于所测元素校准曲线的相关系数0.9990,回收率范围为90.1%～108.1%,相对标准偏差为1.54%～7.57%。正山小种红茶中Na、Mg、K、Ca、Fe、Al、Zn、Mn、Cu、Ge、Cd、Cr、Ni、Se、Mo、Hg、As和Pb 18种元素可用ICP-MS法同时测定,方法简便、快速、准确,灵敏度高。     

ICP-AES法同时测定树脂样品中的15种金属元素

研究建立了电感耦合等离子体发射光谱法(ICP-AES)同时测定离子交换树脂中Al、Ba、Ca、Co、Cr、Cu、Fe、K、Li、Mg、Mn、Na、Ni、Pb、Zn等15种金属元素的方法,进行了必要的条件试验,选择了分析谱线及其仪器工作参数;考察了无机酸的酸度对测定的影响;在优化条件下,进行了准确度和精密度试验,方法的回收率和精密度分别在87.1%～103.4%和0.5%～5.3%范围,该方法各元素的检出限能满足实验要求,适合离子交换树脂中元素含量的常规分析.     

电感耦合等离体原子发射光谱法测定高纯银中25种微量元素

应用银生成氯化银沉淀分离银,超声雾化,ICP-AES法测定分离液中Al、Au、Ba、Bi、Ca、Co、Cr、Cu、Fe、Li、Mg、Mn、Mo、Ni、Pb、Pd、Pt、Sb、Se、Sn、Te、Ti、V、Y及Zn 25种微量元素.选择了被测元素的分析线,考察了载气流量,HNO3浓度和Ag的沉淀对测定元素的影响.取样2.5 g时,测定范围为10～320μg/g,回收率在93%～108%之间,相对标准偏差((RSD n=6)在2.9%～11%之间.     

基于全反射X射线荧光光谱测定污水痕量重金属元素

以Ga为内标,探究全反射X射线荧光光谱（TXRF）快速测定多质量梯度浓度多元素重金属溶液Mn、Fe、Co、Ni、Cu、Zn、As、Cd、Sn、Sb和Pb的可行性,并以实际生活污水为研究对象,比较分析了离心、过滤和消解3种预处理方式对测定污水中重金属元素的影响。实验结果表明,Mn、Fe、Co、Ni、Cu、Zn、As和Pb,较适宜用TXRF直接进行定量分析;Pb的Lα与As的Kα谱线重叠,致使As的回收率略高于其它元素;Cd、Sn和Sb元素,仅可用于趋势分析。当质量浓度为40和4 mg/L时,Mn、Fe、Co、Ni、Cu、Zn和Pb元素呈现出较高的准确度和精密度,回收率在99%～117%之间,相对标准偏差（RSD）处于1%～14%。随着质量浓度的逐渐降低,各元素的准确度和精密度表现出不同程度的下降,当质量浓度处于本次试验的最低水平4μg/L时,大部分元素的回收率与RSD已超出定量分析的要求。通过对生活污水的3种预处理方式进行比较,发现污水悬浮颗粒同样携带部分金属元素,经消解后,Mn、Fe、Co、Ni、Cu和Zn这6种元素的准确度和精密度最好,质量浓度范围在36～152μg/L之间,回收率均...     

ICP-AES法对黑豆和红小豆中15种元素的比较研究

采用ICP-AES法同时测定黑豆和红小豆中Na、Sn、Ca、Zn、Cu、Mg、Al、Fe、P、K、Si、Se、Ba、Mn、Mo等15种元素含量,并对各元素进行了加标回收实验, 黑豆和红小豆中各元素的平均回收率在93.11%～102.15%之间,RSD在0.88%～2.8%之间,检出限介于0.11～14.09μg.L-1。本实验建立了简便、快速、准确和稳定的测定黑豆和红小豆中元素的测定方法。结果显示在黑豆和红小豆中K、Ca 、P 、Mg、Mn、Fe、Zn等常量元素和微量元素含量较高。红小豆中Ca、Mg、Fe、Zn等营养元素的含量较黑豆中的高。     

珠江三角洲肝癌高发区人发重金属元素来源及其影响因子分析

目的为解析珠江三角洲肝癌高发区人发重金属元素来源,探析其来源影响因子。方法利用电感耦合等离子体原子发射光谱仪对佛山顺德区人发的7种重金属元素Pb、Sr、Zn、Fe、Mg、Mn和Al的含量进行了测定,对人发元素进行多元统计分析。结果研究区居民人发Pb、Al和Fe的平均含量较人发正常值高,而人发Sr的平均含量均低于其它地区的正常值,Zn的平均含量在健康人群人发Zn含量平均值范围内。主成分分析提取的三个主成分可解释总方差的71%,Pb、Sr和Mg属外源性元素;Zn、Fe属内源性元素,可用于生物监测;Al、Mn既是外源性元素又是内源性元素。聚类分析验证了主成分分析的结果。不同年龄的人发元素含量,30岁以上的人发中Al平均含量经t检验显著高于30以下人群,其余元素均无显著差异;不同健康状况和性别的人发元素含量,各元素经统计检验均无显著差异。结论该地区人发中Pb、Al含量较健康人高,可能与肝癌高发有关,值得进步探讨其来源。     

卷心菜和芹菜中的17种元素测定

采用微波消解法处理卷心菜和芹菜样品,并用ICP-AES法测定这两种蔬菜中的17种微量元素Ca,Mg,K,Na,P,Zn,Fe,Cu,Mn,Al,Se,Cr,Ni,Cd,As,Pb,Hg。结果表明,两种蔬菜中均含有丰富的矿物元素Ca,Mg,K,Na,P,芹菜中的矿物元素更高,也存在少量能调节人体生理机能的有益微量元素Zn、Fe、Mn、Al、Cu、Ni,除了卷心菜中Hg含量超标外,其它有害重金属元素均属国家食品安全卫生标准之内。     

微波辅助消解ICP-AES法测定小茴香中20种元素

采用微波消解法处理小茴香样品,电感耦合等离子体发射光谱(ICP-AES)测定其中Na、K、Sr、Ca、Mg、P、As、Zn、Pb、Co、Cd、Ni、Ba、Fe、Mn、Cr、Cu、Al、Ti和B 20种常量和微量元素的含量。20种元素的检出限为0.00002~0.00468μg·mL-1,回收率为89.50%~107.89%,相对标准偏差(RSD)均小6%。结果显示,小茴香果实及其嫩叶中除含有人体必需的常量元素K,Na,Ca,Mg,P外,还含有Fe、Zn、Mn、Cr、Co等必需的微量元素和其他元素Ti、B、Ni、Al、Sr、Ba等。     

利用手持技术改进测定乙醇分子结构实验

利用压强传感器代替排水集气法,改进测定乙醇分子结构实验的仪器装置,并探索最佳反应条件。另外,设计两个空白实验,结合压强变化曲线对实验误差进行相关讨论。     

Neutral diterpenoids of oleoresins of five species of conifers of Transcarpathia

The compositions of the neutral diterpenoids of the oleoresins of five species of conifers growing in the Transcarpathia have been studied. It has been found that the oleoresins ofAbies alba M.,Larix decidua M., andPicea excelsa L. contain more than 50% of neutral diterpenoids. The group and qualitative compositions of the oxygen-containing diterpenoids have been determined. In the oleoresins ofAbies alba,Picea excelsa, andPicea abies tertiary alcohols — cis-abienol and isocembrol — predominate, while inLarix decidua the main component is the hydroxy ester larixyl acetate. Primary alcohols related to the resin acids have been found in all the oleoresins investigated. Features of the distribution of diterpenoids according to the species of conifers have been revealed. The results obtained are necessary for the chemotaxonomy of conifers of the family Pinceae.Novosibirsk Institute of Organic Chemistry, Siberian Branch, Academy of Sciences of the USSR. Translated from Khimiya Prirodynkh Soedinenii, No. 6, pp. 812–816, November–December, 1988.     

光谱仪测试范围的扩展

由于石化行业的生产需要，其材质的使用具有多样性和广泛性，经常会出现顾客委托的测试样品的一个或几个元素跨越光谱仪现有测试程序测量范围的情况。本法通过对光谱仪测试原理的认识，根据光谱仪的测试能力及标样的采集，实现了一个或几个元素测量范围的扩展，并对其测量的影响因素进行了研究。     

Dichroism of absorption and polarization of phosphorescence of molecules of the closed form of nitrobenzospirothiopyran

The spectral-polarization characteristics of absorption and phosphorescence of molecules of the initial form of nitro-substituted indolinospirobenzothiopyran were studied in oriented polyethylene films and in solutions with different polarity. An oscillator model of the electron transitions responsible for the formation of absorption and luminescence spectra was suggested. It was established that the principal differences in the spectral and photophysical properties of the compound studied and its oxygen-containing analog are associated with the fact that the electronegativity of the S atom is lower than that of the O atom. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1143–1146, June, 1997.     

Influence of viscosity of medium on processes of oxygen quenching of excited states of mesoporphyrin

The oxygen quenching rate constants for singlet and triplet excited states of the dimethyl ester of mesoporphyrin IX increase with decreasing viscosity of the medium and reach a maximum at a viscosity of approximately 0.4 mPa·sec, after which the rate constants begin to decrease. The drop in rate constant with increasing fluidity of the medium may be related to a nonequilibrium character of the elementary act in the interaction of the reactants in the solvent cage. In viscous media such as isopropyl alcohol, isobutyl alcohol, and isoamyl alcohol, the reaction radius is greater than the sum of the radii of the reacting particles. The long-range character of these processes is due to the relatively weak dependence of the quenching probability on distance.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 25, No. 2, pp. 161–167, March–April, 1989.     

Determination of heats of detonation and influence of components of composite explosives on heats of detonation of high explosives

The heats of detonation of 20 simple high explosives and explosive mixtures were determined by means of an adiabatic detonation calorimeter designed by the authors. The results indicated that the performance of the instrument was reliable and the experimental data were very accurate. For explosive mixtures, there was a linear accumulative relationship between the heats of detonation of the explosive mixture and its components. Accordingly, the heats of detonation of explosive mixtures could be calculated directly from the heats of detonation of simple explosives and the characteristic heats of other components. The experiments showed that the gold or brass shell of the cylindrical charge could be substituted by a thick-walled porcelain shell, which had the advantage of cheapness.

     

物质分配系数的测定实验改进

实验教学目的是从解决实际问题出发,以实验技术训练和实验设计思想培养为目标。介绍了将单一的物质分配系数测定实验改进为综合实验,提高了实验效果及实验资源利用率。     

Calculation of enthalpies of hydrogenation of hydrocarbons

Sets of hydrogen molecule equivalents have been developed which permit the calculation of hydrogenation of different types of carbon-carbon bonds from ab initio total energies (3-21G and 6-31G* basis sets, and, to a more limited extent, for MP2/6-31G* data) of reactants and products. The calculated enthalpies of hydrogenation are in good agreement with experiment for unstrained molecules, with average errors on the order of 2 kcal/mol. The 6-31G* equivalents allow the enthalpies for strained molecules to be calculated accurately, but the 3-21G equivalents do not. The equivalents for both basis sets have been tested by calculating the enthalpies of hydrogenation of carbon-carbon bonds in nitrogen- and oxygen-containing organic molecules, free radicals, and classical carbocations. The results are in good agreement with experiment in most cases.     

非那雄胺合成工艺改进

非那雄胺能抑制5α-还原酶的活性,明显降低二氢睾酮水平,是一种治疗良性前列腺增生的有效药品。该合成工艺以甾烯酮酸为原料,将其与氯化亚砜反应,无须分离即与叔丁胺反应得17β-酰胺化合物,再氧化开环,环合,氢化,脱氢合成了非那雄胺。经元素分析、IR、1HNMR、13CNMR、MS分析表征了其结构。该法无须使用昂贵的2,2-二吡啶二硫化物和剧毒药品苯亚硒酸酐,且以乙酸铵代替氨气,降低了对设备的要求和腐蚀,更适用于工业生产。