THERMOCHIMICA ACTA
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2024
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IF 3.1
Huimin Yan,Fan Yang,Nan Yin,Yan Kou,Quan Shi
Adiabatic calorimetry is a reliable method for determining the purity of organic compounds, offering significant advantages over chromatography by eliminating the need for impurity separation. Despite its longstanding application, research in this area has been limited. This study comprehensively assessed the purity of tetradecanoic acid, n-heptadecane, and phenol using adiabatic calorimetry, comparing the results with those obtained through chromatography. The results demonstrated that tetradecanoic acid purity can be accurately measured, while n-heptadecane exhibited satisfactory repeatability in purity determination without sample separation in polycrystalline forms. Furthermore, the purity of phenol was effectively assessed using adiabatic calorimetry, where chromatography faced challenges. Overall, this study validates adiabatic calorimetry as a robust technique for organic compound purity determination and suggests avenues for further research in this domain.
研究领域:
化学
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分析化学
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DOI
高影响因子
CHEMICAL PAPERS
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2020
·Vol. 74
·期 11
·3987-3993
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IF 1.68
Pan Binfeng,Zhang Zhimin,Lu Xuchen
Abstract The reaction between rare earth oxychloride (REOCl) and water was investigated. X-ray diffractometer, volumetric titrations, FTIR spectrograph and scanning electron microscope were used to determine the reaction process and the reaction products. It was found that the reaction could be concluded as follows: 5REOCl(s) + 5H 2 O(l) = 2RE 2 (OH) 5 Cl(s) + RE 3+ (aq) + 3Cl − (aq). Based on this reaction, a new method for determining the purity of anhydrous rare earth chloride was proposed. Compared with the conventional method, the maximum absolute error decreased from 22 to < 1% and the maximum relative error decreased from 111 to < 4% under the experimental conditions. Graphic abstract
研究领域:
化学
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材料科学
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产品关联
DOI
高影响因子
ANALYTICAL AND BIOANALYTICAL CHEMISTRY
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2025
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IF 3.8
Wu Huaxin,Huang Ting,Zhang Wei,Yao Huan,Li Xueyao,Su Ping,Yang Yi
In the biomedical and chemical fields, purity assessment of compounds is a critical step in ensuring product quality and safety. In this study, a method for purity quantification was proposed as two-signal suppression–internal standard correction–high-performance liquid chromatography–quantitative nuclear magnetic resonance (TSS-ISC-HPLC-qNMR). The two-signal suppression effectively suppresses the interference of solvent signals in the NMR spectra, and the internal standard correction eliminates the influence of many variables during sample preparation and analysis. The purity result (99.89%) of the quantification of certified reference material of acesulfame (AF) by this method matched with the certified value (99.88%), which verified the accuracy of the method. The purity result (with standard deviation) of 94.42% ± 0.10% for the quantification of the low-purity drug digitoxin by the method matched with the purity result of 94.42% ± 0.11% by qNMR with deconvolution (as a validated method), which proved that the method could be used for the quantification of low-purity compounds. The methodology achieved a substantial reduction in total analysis time, from 28 to 4 h (considering only the routine analysis time after optimization), in contrast to the ISC-HPLC-qNMR approach. Additionally, it effectively decreased bias to undetectable with a standard deviation of 0.10%, while the bias of the TSS-HPLC-qNMR method was 0.93%. The present method ensures the accuracy of the quantitative results while demonstrating a low economic burden and significant time efficiency, which shows great potential for application in the accurate quantitative analysis of low-purity organic compounds. Graphical
研究领域:
分析化学
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药物分析
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生物医学
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DOI
PubMed
高影响因子
MICROCHEMICAL JOURNAL
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2024
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IF 4.9
Xinru Tang,Hui Zhang,Shugui Huang,Zeyuan Deng,Chuan Sun,Xiaomao Sun,Hongyan Li
In our country, sodium selenite and sodium selenate are still used as nutritional fortifiers of selenium. Both of them are inorganic selenium, the absorption effect of human body is lower, the risk of toxic wind is larger, and it is easy to cause selenium poisoning. L-selenium-methylselenocysteine (L-SeMC) is a good source of organic selenium, which has higher biological activity and availability. At present, L-SeMC solid standard materials have not yet been developed, a high accuracy and low technical requirement method is needed to determine the purity of candidate reference materials (RMs). In this way, the key steps in the development of reference materials can be completed, and provide a source of high quality selenium supplement for people. In this paper, the candidate structures were identified and analyzed by high performance liquid chromatography (HPLC), Fourier transform infrared (FTIR), and nuclear magnetic resonance (NMR). Homogeneity, together with stability were also measured by HPLC. The sample can be transported for a short period of one month under normal conditions, which can also be stored for a long time within the temperature range of −20 °C to room temperature for more than one year. The purity of L-SeMC measured by mass balance method and quantitative nuclear magnetic resonance (qNMR) was 99.5 % with an expanded uncertainty of 0.4 % (k = 2). However, differential scanning calorimetry (DSC) was not suitable for the purity determination of L-SeMC samples. This method has a wide range of applications and may provide a reference for the purity determination of other RMs.
研究领域:
分析化学
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营养科学
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材料科学
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）