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综述了未知物组分剖析的技术特点及难点。介绍了剖析的一般实施步骤及常用仪器方法,对定性定量困难等问题进行讨论。归纳了未知物组分剖析技术在成分分析、反向工程、健康环保及失效分析领域的最新应用进展。 相似文献
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采用高效液相色谱-四极杆/飞行时间质谱(HPLC-QTOF/MS)建立了阿莫西林克拉维酸钾混悬剂(ACPS)中未知组分的鉴定方法,以BDS Hypersil C18(4.6 mm×250 mm,5μm)为色谱柱,以乙腈-水(0.1%甲酸)为流动相,流速为1 mL/min。比较了中国药典方法和HPLC-QTOF/MS方法的相关性;利用半制备液相色谱收集未知组分,并在HPLC-QTOF/MS体系中进行定位和确认,确定未知组分在液质体系中的出峰位置和准确分子量;筛查混合空白辅料成分,并通过与标准品比对,利用HPLC-QTOF/MS鉴定ACPS的未知组分为糖精钠。方法可为抗生素药品中未知组分的鉴定提供参考。 相似文献
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建立了气相色谱-质谱(GC-MS)和超高效液相色谱-串联四极杆飞行时间质谱(UPLC-Q-TOF MS)技术联合鉴定检材中flubromazolam的方法。未知样品用甲醇和水提取,取上清液,采用GC-MS和UPLC-Q-TOF MS进行分析。经GC-MS检测,保留时间为17.96 min的未知组分的质谱碎片主要特征离子峰有m/z 222,341,343,370,372,111,102,75。经UPLC-QTOF M S检测,保留时间为4.99 min的未知组分的准分子离子峰为m/z 371.0298,碰撞诱导解离(CID)模式下二级质谱主要离子有m/z 343.0114,302.9928,292.1118,263.0982,237.0951,223.0670。经美国缉毒署毒品分析谱库、缴获毒品分析科学工作组(SWGDRUG)分析谱库检索和文献查询获得的信息资料进行比对,确认目标物为flubromazolam。 相似文献
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由气相色谱分离和收集混合物的某一组分,进行显微红外光谱定性鉴定,是确证未知组分的有效方法之一,它能使微量分析的分离与鉴别有效地结合。基本过程:气相色谱馏出物温度较高,当一些不易挥发的待测组分流出时,碰到较低温的吸附剂时立即直接凝聚在吸附剂上,这种技术又称冷阱技术。将收集物做红外光谱分析,可准确地做出定性鉴定。用红外光谱测试常用的溴化钾作吸附剂,使收集与测试同用一载体而避免了物质转移的损失,由于采用分析 相似文献
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正交投影回归法和HLAE用于解析灰色体系 总被引:1,自引:0,他引:1
提出一种基于正交投影的用于判断未知干扰组分的新方法--正交投影回归法(OrthogonalProjection-basedRregression,OPR),可指示出复杂体系中未知干扰组分存在与否及存在区间;在此基础上,应用最近提出的扩展的HLA算法(HLAE),对一维生素混合体系进行了分析,并与HLA和PLS的结果进行了比较.结果表明,OPR是HLAE得以成功应用的前提;不需待测组分的精确光谱,HLAE可得到优于PLS和至少相当于HLA的结果,在纯光谱不够精确的情况下,完全可以用HLAE代替HLA. 相似文献
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采用迭代目标转换因子分析法(ITTFA)解析动力学模型未知的化学反应过程中的动力学-光谱数据矩阵,获得了各组分的动力学谱.基于体系中各组分间的等吸收点等光谱特征,提出并建立了一种新的初始迭代矢量的方法.利用该方法解析了动力学模型未知且各组分均有吸收的两步连续反应的模拟数据矩阵,并对最终产物无吸收的水杨酸水溶液电降解反应过程中测得的数据矩阵进行解析,获得了可靠的结果. 相似文献
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由偏钛酸与钴、镍和锌的盐或氧化物在高温下煅烧合成11个不同颜色的多元氧化物。X-射线粉末衍射数据表明所有样品的结构:组分NiO摩尔数不超过TiO_2的样品是反式尖晶石型晶体,反之,样品是混合晶体。紫外-可见吸收-反射谱图表明10-11号样品同其他的比较具有变窄了的和高的反射峰。这样,它们可以作为绿色的陶瓷颜料。并探讨结构和光谱随组分而改变的原因。 相似文献
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The nanomechanical properties of beta-galactan, a 1 --> 4 linked beta-d-galactose polysaccharide, were investigated with AFM-based single-molecule force spectroscopy. AFM captured a unique plateau at 640 pN in the force spectrogram of beta-galactan, which is significantly different than the plateau at 280 pN in the force spectrogram of amylose. Thus, our results demonstrate that force spectroscopy is able to discriminate between sugar isomers in which axial and equatorial bonds at C1 and C4 are swapped. 相似文献
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采用气相色谱-质谱(GC-MS)联用技术,根据汽油原样中的特征成分,对未加入和分别加入汽油燃油精、海龙燃油宝的汽油燃烧烟尘进行对比分析.结果表明,汽油燃油精的加入会使汽油燃烧烟尘中各类特征成分的百分含量有所变化,但对谱图和特征成分的影响较小;而海龙燃油宝的加入对汽油燃烧烟尘的谱图、特征成分及其个数、各类特征成分的百分含量均产生较大影响.结果为火灾物证鉴定提供一定的参考依据. 相似文献
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介绍气相色谱-质谱联用仪的常见故障:与质谱仪调谐相关的故障、与校准和灵敏度相关的故障及与色谱图和质谱图相关的故障,给出了产生故障的可能原因,提出了故障排除的方法。 相似文献
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PVA-PAMPS-PAA三元互穿网络型水凝胶的合成及其性能研究 总被引:4,自引:0,他引:4
以2-丙烯酰胺基-2-甲基丙磺酸(AMPS)、丙烯酸(AA)以及聚乙烯醇(PVA)为原料,制备了PVA-PAMPS-PAA三元互穿网络型(T-IPN)水凝胶.红外分析表明,PVA与PAA以及PAMPS之间形成了较强的氢键,使得PVA分子上的C—O伸缩震动吸收峰移向了低波数处.X射线衍射以及电镜分析表明,当PVA用量较低时,PVA能均匀的穿插于凝胶网络中,形成完善的互穿网络结构,当PVA用量过高时,部分的PVA结晶而使得凝胶出现相分离.研究了该三元互穿网络型水凝胶的溶胀性能,结果表明,该水凝胶的平衡溶胀比在200至340之间,并且随着AA以及AMPS用量的增加,凝胶的溶胀速率以及平衡溶胀比均升高.该三元互穿网络型水凝胶在酸性溶液中和在碱性溶液中表现出截然不同的消溶胀性能;并且随着溶液pH的升高,凝胶在pH=9.0附近出现体积突变,表现出pH敏感性.通过研究T-IPN水凝胶的抗压缩性能发现,利用线型高分子、柔性高分子网络以及刚性高分子网络制备的三元互穿网络型水凝胶能在高溶胀比下保持较高的强度.溶胀比为180的T-IPN水凝胶,其最大抗压缩强度可达12.1 MPa.进一步研究发现,凝胶的组成以及溶胀比均对凝胶的抗压缩强度和压缩应变均存在较大的影响. 相似文献
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Fabian Weiss Prof.Dr. Frank Kubel Dr. Óscar Gálvez Dr. Markus Hoelzel Dr. Stewart F. Parker Philipp Baloh Dr. Riccardo Iannarelli Dr. Michel J. Rossi Prof. Dr. Hinrich Grothe 《Angewandte Chemie (International ed. in English)》2016,55(10):3276-3280
The composition of high‐altitude ice clouds is still a matter of intense discussion. The constituents in question are ice and nitric acid hydrates, but the exact phase composition of clouds and its formation mechanisms are still unknown. In this work, conclusive evidence for a long‐predicted phase, alpha‐nitric acid trihydrate (alpha‐NAT), is presented. This phase was characterized by a combination of X‐ray and neutron diffraction experiments, allowing a convincing structure solution. Furthermore, vibrational spectra (infrared and inelastic neutron scattering) were recorded and compared with theoretical calculations. A strong interaction between water ice and alpha‐NAT was found, which explains the experimental spectra and the phase‐transition kinetics. On the basis of these results, we propose a new three‐step mechanism for NAT formation in high‐altitude ice clouds. 相似文献
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V. V. Malakhov 《Journal of Analytical Chemistry》2002,57(10):869-874
A hierarchic structure of concepts of the chemical composition of substances, including substances of unknown composition, was proposed on the basis of physicochemical criteria. The latest achievements in the theory and practice of standardless stoichiographic methods for determining the molecular composition of substances (differentiating dissolution and ion chromatography) were considered. 相似文献
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Theoretical spectrograms of the vibrational spectrum of 3,3-dimethylcyclopropene were constructed and juxtaposed with the experimental Raman and IR spectrograms. The theoretical spectrograms are represented as sets of vertical lines starting from the points corresponding to the values of the vibrational frequencies calculated from the scaled quantum-mechanical (QM) force field obtained at the HF/6-31G*//HF/6-31G* level. Two theoretical Raman spectrograms were constructed. In the first case, the heights of the vertical lines correspond to the QM values of the Raman scattering activities. In the second case they represent the relative differential Raman cross-sections calculated using the QM values of Raman scattering activities. The initial vibrational mode matrix remains virtually unchanged upon scaling of the QM force constant matrix because the dispersion of the scale factor values is low. Therefore, the heights of the theoretical lines for the IR spectrogram represent the QM intensities directly. The theoretical spectrogram based on the relative differential Raman cross-sections was shown to depict the experimental Raman spectrum more adequately. This makes it possible to use the results of the corresponding QM calculations more completely and obtain well-substantiated assignments of the vibrational frequencies. 相似文献
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The simultaneous determination of muscle protein and rind protein in mixtures of muscle, soymeal and rind is described. Hydrolysates are derivatized with dansyl chloride and separated by reversed-phase liquid chromatography. The chromatographic pattern is subjected to multivariate evaluation. An indirect calibration method, partial least-squares modelling in latent variables (p.l.s.), is used. The rind protein is determined accurately regardless of sample composition. The accuracy of muscle protein determinations is lower when high concentrations of soymeal are present in the samples, because of the similarity in amino acid composition between soy protein and muscle. The method not only predicts the concentrations of the constituents but also calculates a measure of the similarity between the calibration set and each unknown sample. This gives an indication of the reliability of the predicted concentrations. 相似文献