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α-D-葡萄糖中热分解过程分析检测方案(热重分析仪)

摘 要 本文采用热分析方法和热质联用方法研究α-D-葡萄糖的热分解过程。首先通过热重(TG)和差示扫描量热(DSC)法测量α-D-葡萄糖的熔点以及熔融焓,并通过热质联用法分析α-D-葡萄糖的热稳定性及热分解产物。另外本文对 α-D-葡萄糖的分解动力学加以探讨,讨论了获得可信的动力学参数的实验条件,并将动力学测评的结果用于反应物、产物浓度与等温反应时间的关系的计算,并由此列出了对所测评的动力学数据外推的应用限制。 前 言 热分析技术在药品检验中有着广泛的应用,包括药品熔点的测定、药品的纯度测定、药品多晶型的测定、药品溶剂化物和水分的测定、药品的相容性测定以及稳定性测定等诸多方面。特别是采用热分析方法可以大大加速了稳定性研究进程,并 且通过反应动力学研究来考察药品的稳定性。因此热分析技术在新药研制、中间体检测、处方最佳配方的选择、药物稳定性在我国申报新药中,热分析也被列为控制药品质量的重要分析方法之一。 在药品检验中,最常用的是差示扫描量热法(DSC)和热重分析法(TG)。DSC 可有效地检测到药品是否发生化学反应或物理作用,而 TG 是评价药品热稳定性最直观有效的方法。另外,热分析仪与质谱分析(MS)联用则可以在分子水平上分析复杂机理。本文对糖类化合物的一个典型例子 -- α-D-葡萄糖的热稳定性及热分解过程加以研究,不仅阐明了该化合物的性质,更重要的是通过对 TG、DSC 曲线的详细讨论,探讨了利用热分析方法推断化学反应历程和机理的可行性,并通过与 MS 联用,对放出的气相产物进行同步分析有力地支持了热分析解释。 详情请登陆:http://www.ngb-netzsch.com.cn/technics/applarticles/kinetics%20evaluation%20of%20glucose.html
检测样品: 其他
检测项: 热分解过程分析

德国耐驰热分析

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吡咯里西啶生物碱中精确质量 Q-TOF LC/MS 及全离子MS/MS检测方案(液质联用仪)

Pyrrolizidine alkaloids (PAs) and their N - oxides (PANOs) have serious hepatotoxic effects in both humans and animals, necessitating a method capable of detecting, characterizing, and quantifying them using a robust assay. While triple quadrupole LC/MS systems are ideal for targeted detection, targeted analysis requires standards that are not always easily obtained. Only a fraction of known naturally occurring PAs are available as standards. Triple quadrupole analyses are also not useful for screening unknowns. High - res olution mass spectrometers that provide accurate - mass data enable characterization of unknown PAs/PANOs without the need for specific standards. This application note presents a workflow that uses accurate - mass Q - TOF LC/MS, with All Ions MS/MS and databas e/mass spectral library searching, for the selective and sensitive characterization, screening, tentative identification, and quantification of PAs and PANOs in botanicals and dietary supplements. Twenty - five PA/PANO standards were characterized using their high - resolution accurate - mass MS/MS spectra. These data were used to create a personal com - pound database and library (PCDL) that was then used to screen for PAs/PANOs in 44 botanical and dietary supplement samples. Quantitation was performed using Q - TOF LC/MS response. PAs/PANOs not specifically targeted were tentatively identified using characteristic fragment ions and fragmentation patterns. The PAs/PANOs characterized could potentially lead to the discovery of more unique PAs in additional botan ical and dietary supplement sample s.
检测样品: 其他
检测项: 精确质量 Q-TOF LC/MS 及全离子MS/MS

安捷伦科技(中国)有限公司

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