Optimization of HPLC Analysis of Biogenic Amines with Reference to Molecular Structure

Abstract

The selectivity and molecular connectivity indices (x) up to the sixth order were calculated and compared with measured reversed-phase high pressure liquid chromatographic (HPLC) retention data for biogenic amines common in foodstuffs and animal feed. The separation of seventeen dansylated amines including primary, secondary and polyamines, was investigated using an isoselective multisolvent gradient (IMGE), reversed-phase HPLC method. The mobile phase was optimized with the “PRISMA” model testing thirteen selectivity points. The compounds were divided into two groups according to their retention; the low-order valence level indices best described the retention. As the high correlations between the calculated and observed retention indicate, retention could be predicted in different selectivity points with a high degree of accuracy by the molecular connectivity indices.     

Preliminary study of the retention behavior for different compounds using cryogenic chromatography at different initial temperatures

The Kováts indices (I) of 24 volatile organic compounds were measured at the different initial temperatures by a laboratory-made cryogenic chromatography. The results show that the correlations of the Kováts indices and the temperature are nonlinear at low initial temperature. Seven QSRR models were built using the heuristic method at different initial temperatures by calculating the quantitative chemical parameters of 24 organic compounds to study the relationship between the retention behavior and the molecular parameters. By studying the relationship between carbon and retention behavior, the capacity factor, and resolution of selected compounds, the contribution of gas–liquid interfacial adsorption process, which influences the retention behavior of solutes, is becoming more and more important with the decrease of the initial temperature.     

香水百合香气成分的气相色谱保留指数三维定量构效关系研究

采用比较分子场分析（CoMFA）和比较分子相似性指数分析（CoMSIA）方法,研究了香水百合中38种香气成分分子结构与气相色谱保留指数值之间的定量构效关系。用外部测试集验证法和留一交叉验证法对模型的稳健性和预测能力进行了检验,并通过CoMSIA模型和CoMFA模型的分子场三维等势图研究了这些化合物分子中不同化学结构对保留指数值的影响。检验结果表明,所建立的CoMSIA模型和CoMFA模型都具有较好的稳健性和预测能力,且能够合理解释结构对保留指数值的影响,可应用于对香水百合香气成分的色谱保留指数值的预测。与CoMFA模型相比,CoMSIA模型的预测准确度更高,在香水百合香气成分的色谱定量构效关系研究中,显然有更好的应用前景。     

Comparison of the Topological and Dynamic Characteristics of Molecules for Calculating Retention Indices of Organic Compounds

This paper reports on a comparative analysis of the linear correlation equations relating the gas-chromatographic retention indices (RI) of several groups of isomeric organic compounds to the topological (Wiener and Hosoya indices) and dynamic (intramolecular energies estimated by molecular dynamic methods and the vibrational components of this energy estimated with simple models) parameters of molecules. It is shown that the choice of one of these parameters does not ensure the best approximation to RI, since the results depend on the chemical nature of substances. Correlations between all of the above quantities have been established. The correlations serve as a basis for physicochemical interpretation of the topological parameters of molecules as quantities proportional to the intramolecular vibrational and rotation energies.     

顶空进样GC-MS结合保留指数分析墨旱莲挥发性成分

采用顶空-气相色谱-质谱法(HS-GC-MS)对墨旱莲的挥发性成分进行检测,并结合保留指数对其分析鉴定。结果检测到60个组分,鉴定出33个可能的组分,占挥发性成分的70.0%。该研究为墨旱莲药材挥发性成分的指纹图谱研究奠定了基础。     

Analysis of Mixtures Containing Unknown Components by Gas Chromatography: Determination of Molecular Mass

New methods are proposed for the gas-chromatographic determination of the molecular masses of unknown components in complex mixtures within one cycle of analysis. The methods are based on the use of complex chromatographic data in the form of linear retention indices of compounds for a column with a nonpolar stationary phase and sensitivity indices of a thermal conductivity detector and a flame ionization detector.     

Use of Large Retention Index Database for Filtering of GC–MS False Positive Identifications of Compounds

The use of the large retention index database for identification and filtering of false positive hits in GC–MS analysis of the ylang-ylang essential oil is illustrated. Differences between experimental retention indices and database values of retention indices of candidate compounds provide additional constraints on the list of candidates for a target compound. Over 100 components of ylang-ylang essential oil (total grade) were identified. The main components, with concentrations more than 4?%, are β-caryophyllene, germacrene D, benzyl benzoate, linalool, geranyl acetate, α-(E,E)-farnesene and isobornyl acetate.     

Use of Large Retention Index Database for Filtering of GC–MS False Positive Identifications of Compounds

The use of the large retention index database for identification and filtering of false positive hits in GC–MS analysis of the ylang-ylang essential oil is illustrated. Differences between experimental retention indices and database values of retention indices of candidate compounds provide additional constraints on the list of candidates for a target compound. Over 100 components of ylang-ylang essential oil (total grade) were identified. The main components, with concentrations more than 4 %, are β-caryophyllene, germacrene D, benzyl benzoate, linalool, geranyl acetate, α-(E,E)-farnesene and isobornyl acetate.

     

Effect of the topology of benzotriazole derivatives on their chromatographic retention under RP-HPLC conditions

Sixth order connectivity indices are calculated for 29 benzotriazole derivatives. Correlations between the connectivity indices, physicochemical characteristics, and retention factors of the mentioned compounds are obtained for reversed-phase high-performance liquid chromatography conditions. Based on the correlations obtained, a predictive calculation of the retention factors of some benzotriazole derivatives is performed.     

Use of molecular connectivity indices to predict LC retention of dansylamides in six different eluent systems

Summary Molecular connectivity indices (x) through the sixth order were calculated and compared with measured reversed-phase liquid chromatographic retention data of sixteen dansyl derivatives of amines (dansylamides). Retention measurements were performed in the capacity factor, k′, range 1–30 with organic solvent-water eluents using acetone, acetonitrile, ethanol, methanol, 1-propanol and 2-propanol. Mainly valence level indices were selected to describe retention. Indices of different order were selected in the different eluents, suggesting that there are differences in the retention mechanism in these eluents. Retention can be predicted with great accuracy by the molecular connectivity indices, as the high correlations between the calculated and observed retention indicate. Presented at the 15th International Symposium on Chromatography, Nürnberg, October 1984     

The role of electric interaction in the retention index cencept. Universal interaction indices for GLC,HPLC and TLC

Summary New electric interaction indices are proposed which can universally be used in GLC, HPLC and TLC. These indices can easily be calculated from a variety of the commonly used retention parameters, such as Kováts' retention indices, relative retention times, capacity factors, or R_F values, and the average molecular polarizabilities of the reference compounds. Calculation examples for polycyclic aromatic hydrocarbons and n-alkanes are given. Application of the electric interaction indices for studying the retention mechanism is demonstrated.