ICP-AES分析高纯氧化镥中痕量稀土杂质的研究

使用ICP光源和倒数线色散率4.5A/wm的平面光栅摄谱仪,研究不同型的同心气动雾化器的雾化效率、乙醇的影响及电感耦合等离子体发射光谱分析的有关条件。Lu_2O_3溶液浓度为10mg/ml,用LB喇叭型雾化器引入光源中,获得15个稀土杂质的测定下限为0.1～5μg/g。本方法的相对均方偏差为4.6～12.8％,加料回收率为88～117％。方法适用于纯度为99.996％高纯Lu_2O_3中稀土杂质的分析。     

微波等离子体光谱技术的发展(一)

微波等离子体光源是一类有较强激发能力的原子发射光谱光源,主要包括微波感生等离子体光源(MIP),微波电容耦合等离子体光源及微波等离子体炬光源。文章分两部分,第一部分介绍了微波感生等离子体光源的结构原理和性能,并对它们的技术特点和进展进行评述。低功率微波感生等离子体光源用于直接测定溶液中某些痕量金属元素是比较困难的,如Pb,Hg,Se等元素,但它已成功地与气相色谱联用用于测定C,H,O,N,S等难激发的非金属元素。高功率磁场激发的氮-微波感生等离子体光源(N2-MIP),允许使用通用玻璃同心雾化器产生湿试液气溶胶直接进入等离子体核心,等离子体能稳定运行,其分析性能近似于商用ICP光源,且运行费用低廉,是有发展前景的一种新型原子发射光谱光源。     

Li2Mg2Si4O10F2、H2Mn8O16·1.4H2O和Li1.3Ti1.7Al0.3(PO4)3在高浓度LiCl水溶液中的离子交换行为

研究了用功能材料 Li2Mg2Si4O10F2(LHT)、 H2Mn8O16@ 1.4H2O(CRYMO)和 Li1.3Ti1.7Al0.3(PO4)3(LTAP)分别去除高浓度氯化锂水溶液中的杂质 Fe3+、 K+和 Na+ .实验结果表明,这几种功能材料分别对溶液中的杂质 Fe3+、 K+和 Na+有很高的选择性,除杂效果明显 .分析和研究了这几种功能材料在高浓度氯化锂水溶液中分别与 Fe3+、 K+和 Na+的交换行为 .结果表明,在高浓度氯化锂溶液中这几种功能材料与杂质交换的动力学行为可近似用 JMAK方程描述.     

直读光谱仪单SAFT光源测定锌锭中的杂质元素

采用直读光谱仪单SAFT光源测定锌锭中杂质元素的含量。通过试验确定仪器工作条件如冲洗时间、预激发时间、SAFT激发时间等。将样品用车床加工出符合测定要求的平面,在选定的仪器工作条件下,单独使用SAFT光源对样品进行激发,测量发射光强度,根据工作曲线计算并输出杂质元素含量。该方法测定锌光谱标样中杂质元素含量的结果与标准值相符,与其它方法比对结果一致,测定结果的相对标准偏差不大于5%(n=11),所有元素的线性相关系数均大于0.999 7。该方法准确度高,精密度好,可用于测定锌锭中的杂质元素含量。     

Li2Mg2Si4O10F2、H2Mn8O16•1.4H2O和Li1.3Ti1.7Al0.3(PO4)3在高浓度LiCl水溶液中的离子交换行为

研究了用功能材料Li2Mg2Si4O10F2 (LHT)、H2Mn8O16•1.4H2O (CRYMO)和Li1.3Ti1.7Al0.3(PO4)3 (LTAP)分别去除高浓度氯化锂水溶液中的杂质Fe3＋、K＋和Na＋.实验结果表明，这几种功能材料分别对溶液中的杂质Fe3＋、K＋和Na＋有很高的选择性，除杂效果明显.分析和研究了这几种功能材料在高浓度氯化锂水溶液中分别与Fe3＋、K＋和Na＋的交换行为.结果表明，在高浓度氯化锂溶液中这几种功能材料与杂质交换的动力学行为可近似用JMAK方程描述.     

火焰原子吸收光谱法测定固态磷扩散源中钾钠

大规模集成电路用磷扩散源,是国际上70年代发展起来的新型扩散源材料。自1980年由中国建筑材料科学研究院研制成功固态磷扩散源。磷扩散源中主成分P_2O_5、Al_2O_3的量分别为70.68％、10.76％,杂质K_2O、Na_2O的含量均小于0.05％。至今,未见有关固态磷扩散源中杂质及主成分化学分析的文献。查得唯一文献是对液态磷源(PCl_3、POCl_3中杂质元素的发射光谱分析。     

X射线荧光光谱法测定氧化铝中杂质元素

应用X-射线荧光光谱法测定了氧化铝中11种杂质成分（SiO2，Fe2O3，Na2O，K2O，CaO，TiO2，P2O5，ZnO，V2O5，Ga2O3，Cr2O3）。试样用四硼酸锂和偏硼酸锂作混合熔剂融熔制成玻璃状片形熔块。通过在高纯氧化铝中加入一定量的上述11种元素的纯氧化物配制成中间标准样品，并用此中间标准样品和纯氧化铝作为空白试样组成高、低标，制备了校正曲线。又用此中间标准样品与纯氧化铝按一定比例配制控制样品对分析过程进行质量控制。对所提出方法的精密度进行了考核，结果表明以上11种杂质成分测定结果的RSD值均小于10％。用4种标样对此方法的准确度进行验证，结果表明所得测定值与已知值之间的误差均符合标准规定。     

毛细管气相色谱法测定丙烯中烃类杂质的含量

以PLOT／Al2O3石英毛细管柱为分析柱,采用氢火焰离子化检测器,建立了测定丙烯中烃类杂质含量的毛细管气相色谱法。丙烯中烃类杂质含量测定结果的相对标准偏差小于5％,分析时间约30min,测定值与国家标准方法基本一致。该方法操作简便,分析速度快,准确度高,重复性好。     

碳分子筛柱在微量H_2O、CO、CO_2、N_2O、CH_4、C_2H_2色谱分析上的应用

本文讨论了检出灵敏度的提高、操作条件的选择及定量等问题,提出了一种用于微量H_2O、CO、CO_2、N_2O、CH_4、C_2H_2分析的简易色谱法。工作结果表明,本法适用于一个比较广泛的样品范围,并能快速、高效地在1分钟左右检出样品中上述微时杂质。     

2004年全国高中学生化学竞赛实验试题

由工业锌焙砂提取七水合硫酸锌及产品分析1　实验原理和内容硫酸锌是合成白色颜料锌钡白的主要原料。本实验以工业锌焙砂 (含约 6 5 %的ZnO)为原料 ,经稀硫酸浸出 ,除去不溶性硅酸盐等杂质 ;用ZnO调酸度 ,H2 O2 氧化除铁 ,锌粉置换除去Cu2 + ,Co2 + ,Ni2 + ,Cd2 + 等少量杂质后 ,溶液经蒸发浓缩 ,冷却结晶制得ZnSO4 ·7H2 O产品。产品中锌的含量用EDTA容量法滴定 ,杂质铁的含量用硫氰酸钾分光光度法测定。本实验内容 :　　 (1)由工业锌焙砂提取制备七水合硫酸锌。　　 (2 )测定产品中锌的含量。　　 (3)用分光光度法测定产品中杂质…     

Development of an impurity‐profiling method for source identification of spilled benzene series compounds by gas chromatography with mass spectrometry: Toluene as a case study

In this study, an impurity profiling method was established for the source identification of spilled benzene series compounds. Toluene was used as a case study to demonstrate the feasibility of this approach. Gas chromatography with mass spectrometry was applied for identification and quantification of the impurities including ethyl benzene, p‐xylene, m‐xylene, and o‐xylene in toluene. Impurities in toluene were detected at very low levels by applying mass spectrometry in selected‐ion monitoring mode. Eight authentic toluene samples collected from different manufacturers were analyzed by the developed gas chromatography with mass spectrometry method to construct the characteristic impurity profiling of toluene. Then, combined with scatter distribution, similarity analysis and t‐test, a suite of diagnostic ratios based on the impurity distribution was used for the differentiation of toluene from different sources. Results indicated that scatter distribution method can discriminate the original toluene samples from different manufacturers. Similarity calculation and t‐test methods can identify effectively the weathered toluene samples. The proposed impurity profiling method was useful for discrimination between toluene samples from different sources. Statistical analysis of these impurity profiles demonstrated the potential to investigate whether two questioned spilled toluene samples encountered in forensic casework are from the same source.     

Investigation of the sample characteristics needed for the determination of the origin of uranium-bearing materials

A set of 35 uranium ore and 10 yellow cake samples, collected worldwide from different mines and production sites, were analyzed for their impurity spectrum by ICP-MS. Pattern recognition techniques such as cluster analysis were applied to the data set in order to characterize samples with relation to their geographical origin. The results obtained show a clear relationship between samples taken from the same geological origin and constitute a satisfactory fingerprint for establishing the origin of the material. In addition to the impurity data, data on the isotopic composition of radiogenic lead is used to resolve ambiguity when impurity cluster analysis fails to deliver unambiguous origin data.     

电感耦合等离子体发射光谱法测定二硼化锆中26种杂质

建立微波消解样品,电感耦合等离子体发射光谱法测定二硼化锆中26种杂质元素含量的方法。根据二硼化锆的化学组成对杂质检测的影响,确定了各元素最佳分析线;通过考察不同浓度的锆基体对待测元素的影响来确定最佳锆基体浓度;通过萃取法分离硼元素,消除硼对杂质检测的干扰;采用基体匹配法、多谱拟和技术消除了锆基体的干扰。在选定的仪器工作条件下,各待测元素的质量浓度与信号强度成良好的线性关系,线性相关系数均大于0.999。测定结果的相对标准偏差不大于6%(n=11),样品加标回收率为94%~101%。该方法操作简便,测定结果准确,可用于二硼化锆中26种杂质元素的测定。     

Development of certified reference samples of solutions of trihalomethanes

A method for the metrological certification of reference samples (RS) of solutions of organic compounds was proposed. The method is based on a procedure of sample preparation that uses both calculated and experimental data and involves the evaluation of the purity of the reagents employed. Impurity components were identified. Procedures for the determination of impurity components in source materials by gas chromatography with flame-ionization detection were developed. Calibration coefficients for halogen-containing impurity components in reference to an internal standard were determined experimentally or calculated. Certified reference samples of solutions of trichloromethane, bromodichloromethane, dibromochloromethane, and tribromomethane were designed for the quality control of drinking water     

Validatibility of a capillary isoelectric focusing method for impurity quantitation

A strategy is presented for examining the validatability of a capillary isoelectric focusing (cIEF) method, intended for quantitation of product-related impurities in a protein drug substance, according to guidelines published by the International Conference on Harmonization (ICH). The results of this study demonstrate the suitability of cIEF as an analytical method for the quantitation of two product-related impurities in a protein drug substance: a monodeamidated degradation product and an aggregated form of the parent molecule. A range of impurity levels was generated by spiking the isolated impurity species, into a representative production lot of the drug substance. Six impurity spike levels (0.5-12% impurity for deamidated species and 0.5-8% impurity for aggregated species) were analyzed in triplicate. Measurement of impurity peak area percent in the spiked samples provided the data for computing specificity, accuracy, precision, linearity and limit of quantitation (LOQ) for the impurities. Accuracy, defined as the agreement of peak area percent for impurity species with the theoretical impurity percentage from the spike ratio, was 85-96% for the deamidated species and 73-97% for the aggregated species. A linear relationship was found between the measured area percent and the theoretical percent impurity for both impurity species (coefficient of determination, r2=0.9994 for deamidated species and =0.9827 for aggregated species). Precision (repeatability) studies demonstrated a low relative standard deviation (RSD) value (<6%) at all spike levels for both impurity species. Intermediate precision and reproducibility were evaluated by simulating many of the multivariable testing conditions expected during the life cycle of an analytical method, such as multiple equipment and laboratories. Repeated analyses of the drug substance under these varied conditions, yielded RSD values of <20%, for both impurity species. The LOQ, defined as the lowest impurity level where both accuracy and precision were achieved, was assigned at the 0.5% impurity level for both impurity species. This work illustrates a successful strategy in applying the ICH validation guidelines for impurity analytical methods to a cIEF method. Moreover, the data demonstrate the ability of cIEF to be used reliably as an analytical method for impurity quantitation.     

Determination of Impurity Arsenic in High-Purity Sulfur by Electrothermal Atomic-Absorption Spectrometry with the Use of Solvent Extraction

A procedure was developed for determining impurity arsenic in high-purity sulfur with a detection limit of 1 × 10^–7 wt %. The samples of sulfur to be studied were dissolved in nitric acid in an autoclave, and then the arsenic impurity was extracted with toluene and back-extracted with distilled water. Arsenic was determined in the back-extract by electrothermal atomic-absorption spectrometry.     

Identification and quantitation of cis-ketoconazole impurity by capillary zone electrophoresis-mass spectrometry

trans-Ketoconazole was identified and quantified as impurity of cis-ketoconazole, an antifungal compound, by capillary zone electrophoresis-electrospray-mass spectrometry (CZE-ESI-MS). The chirality of this impurity was demonstrated separating their enantiomers by adding heptakis-(2,3,6-tri-O-methyl)-beta-cyclodextrin to the separation buffer in capillary electrophoresis (CE) with UV detection. However, MS detection was hyphenated to the CE instrument for its identification. As both compounds are diastereomers, they have the same m/z values and are needed to be separated prior to the MS identification. A 0.4M ammonium formate separation buffer at pH 3.0 enabled the separation of the impurity from cis-ketoconazole. Under these conditions, the optimization of ESI-MS parameters (composition and flow of the sheath-liquid, drying temperature, drying gas flow, and capillary potential) was carried out to obtain the best MS sensitivity. CZE-ESI-MS optimized conditions enabled the identification of trans-ketoconazole as impurity of cis-ketoconazole. In addition, the quantitation of this impurity was achieved in different samples: cis-ketoconazole standard and three different pharmaceutical formulations (two tablets and one syrup) containing this standard. In all cases, percentages higher than 2.0 were determined for the impurity. According to ICH guidelines, these values required the identification and quantitation of any impurity in drug substances and products.     

Identification of an impurity in synthetically prepared GAZT: 4″,5″-dehydro-GAZT

A minor impurity was recorded by hplc during the final purification of synthetically prepared samples of the 5′-0-glucuronide of azidothymidine (GAZT). Following isolation of a small quantity of this impurity by hplc, elucidation of the structure was undertaken. A combination of two-dimensional nmr methods in conjunction with infrared spectroscopy and mass spectrometry were utilized to unequivocally identify the impurity as the 4″,5″-dehydro-5′-O-glucuronide of AZT (DGAZT).     

Capillary electrophoresis-mass spectrometry in impurity profiling of pharmaceutical products

Generally reversed-phase high-performance liquid chromatography (RP-HPLC) methods are extensively applied during quality control of pharmaceutical products. Since capillary electrophoresis (CE) is based on a different separation principle and consequently results in a unique selectivity compared to RP-HPLC, it can advantageously be used as an orthogonal technique. CE equipped with a mass spectrometer detector provides even more information that can be helpful for identification and structural elucidation purposes. CE-MS was recently implemented in the method development approach to support impurity profiling of pharmaceutical products. In this paper the application of CE-electrospray ionization (ESI)-MS/MS to the impurity profiling of galantamine hydrobromide in stressed Reminyl Extended Release (ER) capsules is discussed. Reminyl ER samples were stressed at different storing conditions. The impurity profile of these samples was compared with the current RP-HPLC and chiral CE method, but also with CE-ESI-MS/MS. The combination of these three methods provided valuable data that allowed understanding comprehensively the impurity profile of these samples. Two impurities were detected at concentrations lower than 0.05%, which did not occur in nonstressed samples. Chromatographic data and the fragmentation patterns of galantamine and related compounds were also examined for identification of these two degradation products.     

Impurity diffusion during activation a significant source of systematic errors in neutron activation analysis

Using a layer etching technique impurity profiles of Cu and Fe in silicon samples are measured by n.a.a. Radiation enhanced diffusion of Cu and Fe impurities from the surface into the bulk material has been observed. The samples were etched before irradiation to remove the impurity profiles caused by the sampling procedures.