氢还原重量法测定海绵钯产品灼烧损失量的研究

系统地研究了氢还原重量法测定海绵钯灼烧损失量的条件,考察了非金属杂质元素含量对分析结果的影响,并将本法结果与热重法的测定结果进行对照。结果表明:1~2g样品,氢还原分段升温至800℃,重量法测定海绵钯中0.0019%,0.0142%,0.0302%和0.0694%灼烧损失量的极差、标准偏差(S)、相对标准偏差(RSD)和重复性限(r)分别为±0.0005%~0.0028%,0.0001%~0.0007%,1.0%~5.2%和0.0003%~0.0020%。灼烧损失量主要由氧、氮含量组成,碳含量对其影响忽略不计。方法结果准确、精密,且与热重法的分析结果吻合,能够满足99.90%~99.99%的海绵钯产品的分析要求。     

氢还原重量法测定海绵钯产品的灼烧损失量

系统地研究了氢还原重量法测定海绵钯灼烧损失量的条件,考察了非金属杂质元素含量对分析结果的影响,并将本法结果与热重法的测定结果进行对照。结果表明:1~2g样品,氢还原分段升温至800℃,重量法测定海绵钯中0.0019%,0.0142%,0.0302%和0.0694%灼烧损失量的极差、标准偏差(S)、相对标准偏差(RSD)和重复性限(r)分别为±0.0005%~0.0028%,0.0001%~0.0007%,1.0%~5.2%和0.0003%~0.0020%。灼烧损失量主要由氧、氮含量组成,碳含量对其影响忽略不计。方法结果准确、精密,且与热重法的分析结果吻合,能够满足99.90%~99.99%的海绵钯产品的分析要求。     

氢还原重量法测定氯化钯产品中的钯含量

建立了氢还原重量法测定氯化钯产品钯含量的新方法,系统研究了测定条件,结合ICP-AES法考察了杂质元素对了分析结果的误差影响。结果表明：含钯量约3 g的氯化钯于750 ℃氢还原为海绵钯和105 ℃干燥水气的条件下,测定59.78%、59.98%和60.03%的钯含量,极差、标准偏差(S)、相对标准偏差(RSD,n=22)和重复性限(r)分别为±0.01%、0.0047%～0.0050%、0.0079%～0.0083%和0.009%～0.014%。样品加标准回收率99.98%。本法结果准确、精密,且与GB/T 15072.4-2008标准分析方法的吻合。     

二苯硫脲-醋酸丁酯萃取-石墨炉原子吸收法测定地球化学样品中痕量银

对石墨炉原子吸收光谱法测定地球化学样品中痕量银进行了研究。样品经盐酸、硝酸、硫酸、高氯酸溶解,在盐酸(1.2mol/L)介质中用醋酸丁酯萃取银与二苯硫脲螯合物,用石墨炉原子吸收光谱法测定地球化学样品中痕量银,方法检出限为0.011ng/mL,相对标准偏差(RSD,n=11)为6.0%¹2.2%,加标回收率为96.00%12.2%,加标回收率为96.00%¹05.00%。能满足地球化学样品中银含量为0.02105.00%。能满足地球化学样品中银含量为0.02⁵μg/g范围内银测定的准确度和精密度的要求。     

氢还原重量法测定亚硝酰硝酸钌溶液中的钌含量

采用盐酸前处理样品,干燥后通氢还原纯化,建立了氢还原重量法测定亚硝酰硝酸钌溶液中的钌含量的方法。结果表明,在称样量为4.0g、盐酸加入量3mL,程序升温750℃,保温90min条件下,测定结果最好。测定钌含量为5.50%、10.89%的两种样品,两种样品钌含量分析结果的极差分别为0.11%、0.16%,相对标准偏差(RSD,n=7)分别为0.66%、0.52%,与其他标准分析方法相比,测定结果的准确度和精密度更好。     

固相膜萃取/高效液相色谱法测定环境水体中的磺酰脲类除草剂

建立了一种基于C₁₈固相萃取膜预富集、高效液相色谱法定量分析环境水体中6种痕量磺酰脲类除草剂的快速分析方法。优化了色谱分离条件,考察了洗脱剂种类与体积、水样pH值和盐效应等条件对萃取效率的影响。在优化条件下,6种磺酰脲类除草剂的峰面积与其质量浓度呈良好的线性关系,苯磺隆的线性范围为0.10²0.0μg/L,其余均为0.05²0μg/L,相关系数为0.999 0⁰.999 5,方法检出限为0.019⁰.037μg/L。对地表水和海水的加标回收率分别为92.6%¹05.7%和89.8%¹08.7%,相对标准偏差分别为0.7%⁷.1%和0.5%⁴.0%。该方法操作简单、快速、准确、灵敏度高。     

氢还原重量法测定氯化钯产品中的钯

系统研究了氢还原重量法测定氯化钯产品中钯含量的测定条件,考察了杂质元素对钯分析结果的误差影响。结果表明:于选定条件下,测定59.78%~60.03%含量的钯,极差、标准偏差(SD)、相对标准偏差(RSD,n=22)和重复性限(r)分别为±0.01%,0.0047%~0.0050%,0.0079%~0.0083%和0.009%~0.014%,样品加标回收率达到99.98%,钯分析结果准确、可靠、精密度高。     

氢还原重量法测定三氯化钌产品中钌的含量

建立了氢还原重量法测定三氯化钌产品大样中钌含量的新方法,研究并优化了测定条件,结合原子吸收光谱法(AAS)、电感耦合等离子体原子发射光谱法(ICP-AES)和氯化铵纯度考察了杂质元素对了分析结果的误差影响。结果表明,钌含量为0.3~0.6g的三氯化钌与5~7g氯化铵能完全形成(NH4)2RuCl6配合物,于约100℃烘干水分、350℃分解铵盐、750℃氢还原为海绵钌和105℃干燥水气的条件下,测定3.94%,5.88%,7.32%,9.47%,10.84%和12.93%含量的钌,极差、标准偏差(S)、相对标准偏差(RSD,n=22)和重复性限(r)分别为±0.01%,0.0030%~0.0050%,0.0369%~0.0761%和0.008%~0.014%。样品加标回收率99.96%~99.98%。方法的结果准确,精密度好,且与YS/T562—2009标准分析方法的吻合。     

标准加入法-电感耦合等离子体质谱法测定海绵钯中17种痕量杂质元素

取海绵钯样品0.900 0 g,加入10 mL水润湿后,用10 mL体积比3∶1的盐酸-硝酸混合液于100℃溶解,用水定重至90 g。通过质谱干扰分析并结合同位素丰度确定了待测同位素,⁵²Cr、⁵⁶Fe、⁵⁵Mn在动态反应池(DRC)模式下检测,其他元素的同位素均在标准模式下检测。在射频功率1 100 W、雾化气流量0.85 L·min^-1等条件下,采用电感耦合等离子体质谱法(ICP-MS)测定海绵钯中17种痕量杂质元素,绘制各元素标准加入法的校准曲线,并用仪器软件设置为“外标法”模式的工作曲线,后续对其他海绵钯样品进行检测时可直接在此工作曲线下进行,不需要每个样品都进行标准加入。结果表明,17种元素的检出限(3s)为0.012～0.452μg·g^-1,按照标准加入法进行回收试验,回收率为93.0%～107%,测定值的相对标准偏差(n=11)小于8.0%。采用本方法和GB/T 1420-2015中的电感耦合等离子体原子发射光谱法对海绵钯样品进行对比分析,两种方法的测定结果基本一...     

氟离子选择电极法测定含铜蚀刻废液中氟含量方法探讨

准确测定含铜蚀刻废液中氟含量是含铜蚀刻废液中铜盐回收的关键,本文就含铜蚀刻废液中氟含量离子选择电极测定方法^[1～3]进行探讨与验证。通过样品前处理与试验,离子选择电极一次标准加入法测定下限为0.9mg·L^-1,离子选择电极标准曲线法测定下限为1.2 mg·L^-1;两种方法的相对标准偏差在1.2%～1.7%,两种方法的加标回收率在77%～102%,满足工程应用要求。     

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。     

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。     

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.     

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.     

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.     

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.