气相色谱/质谱结合化学计量学解析方法用于植物精油成分分析

使用气相色谱/质谱(GC-MS)法对缬草精油和含有缬草精油的混配精油的化学成分进行了分析.采用直观推导式演进特征投影法(HELP)对二维数据中的色谱重叠峰进行了解析,得到两种精油的各个物质的纯色谱和纯质谱,同时利用交互移动窗口因子分析法(AMWFA)直接比较两种精油中的共有组分,提取出共有组分的纯质谱,通过与HELP法解析出的质谱进行比较,发现AMWFA法比HELP法能更快速鉴别出混配精油中的缬草精油.     

Analysis of the essential oils of Coriandrum sativum Using GC-MS coupled with chemometric resolution methods

The essential oils extracted from Coriandrum sativum L. were analyzed by GC-MS coupled with chemometric resolution methods. Through the chemometric resolution methods, peak clusters were uniquely resolved into the pure chromatographic profiles and mass spectra of each component. Qualitative analysis was performed by comparing the pure mass spectra with those in the NIST 05 mass spectral library. Quantitative analysis was performed using the total volume integration method. A total of 118 constituents were detected, of which 104 were identified, accounting for 97.27% of the total content. The results indicate that GC-MS combined with chemometric resolution methods can greatly enhance the capability of separation and the reliability of qualitative and quantitative results. The combined method is an economical and accurate approach for the rapid analysis of the complex essential oil samples in Coriandrum sativum L.     

Development of a method for analysis of Iranian damask rose oil: combination of gas chromatography-mass spectrometry with Chemometric techniques

Gas chromatography-mass spectrometry (GC-MS) combined with Chemometric resolution techniques were proposed as a method for the analysis of volatile components of Iranian damask rose oil. The essential oil of damask rose was extracted using hydrodistillation method and analyzed with GC-MS in optimized conditions. A total of 70 components were identified using similarity searches between mass spectra and MS database. This number was extended to 95 components with concentrations higher than 0.01% accounting for 94.75% of the total relative content using Chemometric techniques. For the first time in this work, an approach based upon subspace comparison is used for determination of the chemical rank of GC-MS data. The peak clusters were resolved using heuristic evolving latent projection (HELP) and multivariate curve resolution-alternating least square (MCR-ALS) by applying proper constraints, and the combination of both methods for some cases. It is concluded that a thorough analysis of the complex mixtures such as Iranian damask rose requires sophisticated GC-MS coupled with the Chemometric techniques.     

Towards obtaining more information from gas chromatography–mass spectrometric data of essential oils: An overview of mean field independent component analysis

Mean field independent component analysis (MF-ICA) along with other chemometric techniques was proposed for obtaining more information from multi-component gas chromatographic–mass spectrometric (GC–MS) signals of essential oils (mandarin and lemon as examples). Using these techniques, some fundamental problems during the GC–MS analysis of essential oils such as varying baseline, presence of different types of noise and co-elution have been solved. The parameters affecting MF-ICA algorithm were screened using a 2⁵ factorial design. The optimum conditions for MF-ICA algorithm were followed by deconvolution of complex GC–MS peak clusters. The number of independent components (ICs) (chemical constituents) in each peak cluster was estimated using morphological score method. Eigenvalue profiles of evolving factor analysis (EFA) and pure variables from orthogonal projection approach (OPA) were used as initial mixing matrix (chromatograms) in iterative process. The resolved mass spectra were satisfactorily identified using NIST mass spectral search system. Finally, the results of optimized MF-ICA were compared with those obtained using multivariate curve resolution-alternating least square (MCR-ALS), multivariate curve resolution-objective function minimization (MCR-FMIN) and heuristic evolving latent projection (HELP) methods. It is demonstrated that MF-ICA can be used as an alternative method for a quick and accurate analysis of real multi-component problematic systems such as essential oils.     

Determination of the volatile chemical constituents of Notoptergium incium by gas chromatography-mass spectrometry and iterative or non-iterative chemometrics resolution methods

The qualitative and quantitative determination of the chemical constitutes in traditional Chinese medicine (TCM) is an important task, which builds the foundation of the theory of pharmacological activity. The hyphenated chromatography instruments combined with the related chemometric methods provide powerful tools for the resolution of such complex systems. The familiar chemometrics methods can be roughly divided into two different kinds, the iterative one such as orthogonal projection approach (OPA) and non-iterative one representing by evolving window orthogonal projection (EWOP). One can use different kinds of methods according to overlapping condition, and then the measured data matrix can be resolved into pure concentration profiles and mass spectra of the chemical components with relative high efficiency and acceptable accuracy. One kind of TCM, named Notoptergium incium (NI) was analyzed by gas chromatography-mass spectrometry (GC-MS) and resolved by above chemometric approach. Experiment results show the efficiency and convenience of the proposed approach. 65 of the 98 separated constituents in essential oil, accounting for 92.13%, were identified by mass spectroscopy (MS).     

Determination of the Volatile Oil of Magnolia biondii Pamp by GC–MS Combined with Chemometric Techniques

An optimized temperature-programmed gas chromatography–mass spectrometry system combined with chemometric methods was firstly applied to analyze the volatile components of M. biondii Pamp. A total of 65 components were identified using similarity searches between mass spectra and MS database. This number was extended to 80 components with the help of chemometric techniques. The peak purity of two-way data was controlled by fixed size moving window evolving factor analysis, two dimensional-evolving latent projection graph and three dimensional-evolving latent projection graph. Then the overlapped peak clusters were resolved using heuristic evolving latent projection. The results prove that the reported approach is powerful for the analysis of complex herbal samples.     

Liquid exclusion adsorption chromatography, a new technique for isocratic separation of nonionic surfactants. III. Two-dimensional separation of fatty alcohol ethoxylates

In this paper, a novel procedure for qualitative and quantitative analysis of the two-dimensional data obtained from GC-MS is investigated to determine chemical components of essential oils in Cortex Cinnamomi from four different producing areas. A new method named iterative optimization procedure (IOP) specially used to resolve embedded peaks is also developed. With the help of IOP and other chemometric techniques, such as heuristic evolving latent projections, evolving factor analysis, sub-window factor analysis and orthogonal projection resolution, and etc., the detection of the purity of chromatographic peaks can be first addressed, and then the overlapping peaks are resolved into the pure chromatogram and mass spectrum of each component. The similarity searches in the MS database are finally conducted to qualitatively determine the chemical components. The results obtained showed that the accuracy of qualitative and quantitative analysis could be greatly enhanced by chemometric resolution methods. The chemometric resolution techniques upon the two-dimensional data can be quite promising tools for the analysis of the complex samples like traditional Chinese medicine.     

Characterization and determination of fatty acids in fish oil using gas chromatography-mass spectrometry coupled with chemometric resolution techniques

Characterization and determination of a complex mixture of fatty acid methyl esters was performed for commercial fish oil using two-dimensional GC-MS data coupled with resolution techniques. Various principle component analysis methods such as significant factor analysis and fixed size moving window evolving factor analysis were used for the number of factors, zero concentration and selective regions. Then, the convoluted chromatograms were resolved into pure chromatograms and mass spectra using heuristic evolving latent projections (HELP) method. Fatty acids of C16:1omega7, C18:4omega3, C18:1omega11, C18:1omega9, C18:0, C20:2omega6, C20:1omega9, C22:1omega11, C22:1omega9 and C24:1omega9 were resolved an fied by using similarity searches between deconvoluted mass spectra and MS database, in different parts of total ion current chromatogram. Window target testing factor analysis is also applied for confirming the presence or absence of target analytes. The results of the present work show that combination of hyphenated chromatographic methods and resolution techniques provide a complementary method for accurate analysis of real multi-component systems such as fish oil.     

Analysis of the chemical composition of the essential oil of Polygonum minus Huds. using two-dimensional gas chromatography-time-of-flight mass spectrometry (GC-TOF MS)

The essential oil in leaves of Polygonum minus Huds., a local aromatic plant, were identified by a pipeline of gas chromatography (GC) techniques coupled with mass-spectrometry (MS), flame ionization detector (FID) and two dimensional gas chromatography time of flight mass spectrometry (GC x GC-TOF MS). A total of 48 compounds with a good match and high probability values were identified using this technique. Meanwhile, 42 compounds were successfully identified in this study using GC-MS, a significantly larger number than in previous studies. GC-FID was used in determining the retention indices of chemical components in P. minus essential oil. The result also showed the efficiency and reliability were greatly improved when chemometric methods and retention indices were used in identification and quantification of chemical components in plant essential oil.     

GC-MS与正交投影法或渐进窗口正交投影法用于羌活挥发油成分的测定

中药化学组成的定性定量测定是药物活性理论的基础,联用色谱及其相关的化学计量学方法为中药复杂体系的分离和分辨提供了强有力的工具.采用GC-MS法对传统中药羌活中的挥发油成分进行了分离测定,并对其中重叠色谱峰根据其重叠程度,采用迭代的正交投影法(OPA)和非迭代的渐进窗口正交投影法(EWOP)进行了分辨,得到每个组分的纯色谱和光谱曲线,共分辨出98个色谱峰,通过质谱库检索得到其中65个组分的定性定量结果,占总含量的92.13%.     

A quality control method for geranium oil based on vibrational spectroscopy and chemometric data analysis

Rose-scented geranium, a commercially important cultivar originating from Pelargonium graveolens L’Her. ex Ait., is a high value essential oil extensively used in flavour and fragrance formulations. The oil is variable in composition with ‘Bourbon geranium’ (from Reunion Island) regarded as the highest quality geranium oil. Quality assessment of geranium oil involves profiling seven major volatile constituents (geraniol, citronellol, geranyl formate, citronellyl formate, linalool, isomenthone and guaia-6,9-diene) using gas chromatography (GC). The aim of this study was to explore the feasibility of vibrational spectroscopy in tandem with chemometric methods as a rapid and low-cost alternative quality control method. Geranium oil samples (n = 70) were obtained from different suppliers representing cultivation sites in South Africa, Egypt, India, Reunion Island, China and Madagascar. Reference analysis was performed using gas chromatography coupled to mass spectrometry (GC–MS). The mid-infrared (MIR) and near-infrared (NIR) spectra of the oils were recorded with a total of 32 scans accumulated for each sample. Partial least squares (PLS) multivariate calibration models were developed. The calibration models obtained for both MIR and NIR data produced good correlation coefficients (R² > 0.90) between the predicted and reference values for all seven marker molecules. Generally, the error parameters (RMSEE and RMSEP) after external validation were low (<1.0%) for all compounds guaranteeing reliable predictions. The results show convincingly the potential of both MIRS and NIRS as alternative methods that can be used in quality assessment of geranium oil providing sufficiently accurate results.     

Determination of volatile components in peptic powder by gas chromatography-mass spectrometry and chemometric resolution

Gas chromatography-mass spectrometry (GC-MS) coupled with chemometric resolution upon two-dimensional data was proposed as a method for the analysis of volatile components in a traditional Chinese medicinal preparation peptic powder which contains Rhizoma Atractylodis, Pericarpium Citri Reticulatae, Cortex Magnoliae Officinalis and Radix Glycyrrhizae. Ninety-three components were separated and 65 of them were qualitatively and quantitatively analyzed which represented about 90.28% of the total content. With the help of chemometric resolution, the data were resolved into a pure chromatogram and a mass spectrum of each chemical component. The accuracy of qualitative and quantitative results was greatly improved by using the two-dimensional comprehensive information of chromatograms and mass spectra. The example showed that chemometric resolution could greatly enhance separation ability. This makes it possible to analyze complicated practical systems like traditional Chinese medicinal preparations with the help of coupled instruments and chemometric resolution methods.     

Essential Oil Composition of Osmanthus fragrans Varieties by GC-MS and Heuristic Evolving Latent Projections

The essential oils from two varieties of Osmanthus fragrans have been extracted by steam distillation and analyzed by gas chromatography-mass spectrometry with the help of heuristic evolving latent projections (HELP), an effective chemometric resolution method. The overlapped peak clusters were resolved into pure chromatograms and pure mass spectra with HELP. Identification of the components was by comparison of temperature-programmed retention indices (PTRIs) and by similarity searches in the National Institute of Standards and Technology mass database. Quantitative results were obtained by overall integration of the peaks. The reliability of the qualitative and quantitative results was greatly improved by using HELP and PTRIs. The main components from O. fragrans Lour. var. thunbergii Mak. (TM) and O. fragrans Lour. var. aurantiacus Mak. (AM) were 1,2-epoxy linalool and nonanal, respectively. In total, 52 volatile components in essential oil of TM and 45 in AM were analyzed qualitatively and quantitatively, accounting for 95.67 and 92.28% total contents of the essential oils.     

气相色谱-质谱法与化学计量学分辨法分析当归须挥发油中化学成分

本文借助化学计量学分辨方法,建立了用气相色谱-质谱(GC-MS)联用法分析当归须挥发油成分的方法.对重叠色谱峰采用直观推导式演进特征投影算法进行分辨,从而获得每一组分的纯色谱和质谱,依靠每一组分纯质谱在NIST质谱库进行相似性检索而定性分析,用总体积积分法进行定量分析.在当归须挥发油中共分辨出86个色谱峰,通过质谱库检...     

Identification of an artifact peak co-eluting with formaldehyde-2,4-dinitrophenylhydrazone derivative by GC-MS and chemometrics

A chemometric approach was utilized to identify an artifact peak co-eluting with formaldehyde-2,4-dinitophenylhydrazone. Application of the methods of principal component analysis to the mass spectra of the formaldehyde-hydrazone peaks collected at 200-280 °C has revealed the presence of two factors contributing to these spectra. Moreover, the use of self-modeling curve resolution (SMCR) techniques has enabled the reconstruction of the spectra of the pure components. One of the identified components that contribute to the spectra of the mixture was formaldehyde-2,4-dintrophenylhydrazone, whereas the other component was 1-amino-2,4-dinitrobenzene, a degradation product of 2,4-dintrophenylhydrazine.     

3-己炔-2, 5-二醇在镍电极上电还原反应研究

采用化学计量学中新近发展的二维数据分辨方法,直观推导式演进特征投影(HELP)算法,对3-己炔-2,5-二醇在镍电极上的电还原反应得到的混合物进行了定性定量研究,得到了各组分的纯物质质谱及浓度变化曲线,且可以得到反应动力学的合理解释。说明借助化学计量学可大大扩展色质联用分析的应用范畴。     

Resolution of the essential constituents of Ramulus cinnamomi by an evolving chemometric approach

The analysis of complex mixtures, such as those of traditional Chinese medicine (TCM), is difficult by conventional methods of analysis. Chemometric methods provide a new way to solve such problems. Subwindow factor analysis (SFA) paired with the evolving window orthogonal projection (EWOP) method, has been used as a new evolving approach to the resolution of volatile components of Ramulus cinnamomi (RC). Compared with conventional chromatographic analysis, the chromatographic separation conditions necessary are greatly mitigated in our approach, yet the accuracy of qualitative and quantitative results is improved, because the measured data matrix has been resolved into chromatograms and mass spectra of the chemical components. Our method is, moreover, friendly to use and easy to program. Experimental results show the efficiency and convenience of the proposed approach. Forty-seven of the seventy-eight separated constituents in an essential oil, accounting for 89.55% of the sample, were identified by mass spectroscopy (MS).     

Use of gas chromatography-mass spectrometry combined with resolution methods to characterize the essential oil components of Iranian cumin and caraway

Gas chromatography-mass spectrometry combined with iterative and non-iterative resolution methods was used to characterize the essential oil components of Iranian cumin and caraway. Orthogonal projection resolution (OPR) as a non-iterative and distance-selection-multivariate curve resolution-alternative least squares (DS-MCR-ALS) as an iterative method were used as auxiliary means to the analysis in the case of overlapping peaks. A total of 19 and 39 components were identified by direct similarity searches for cumin and caraway oils, respectively. These numbers were extended to 49 and 98 components, respectively with the help of chemometric techniques. Major constituents in cumin are gamma-terpinene (15.82%), 2-methyl-3-phenyl-propanal (32.27%) and myrtenal (11.64%) and in caraway are gamma-terpinene (24.40%), 2-methyl-3-phenyl-propanal (13.20%) and 2, 4(10)-thujadien (14.02%). In spite of different cultivation conditions, there are 28 components which are common between the two seeds.     

Testing the performance of pure spectrum resolution from Raman hyperspectral images of differently manufactured pharmaceutical tablets

Chemical imaging is a rapidly emerging analytical method in pharmaceutical technology. Due to the numerous chemometric solutions available, characterization of pharmaceutical samples with unknown components present has also become possible. This study compares the performance of current state-of-the-art curve resolution methods (multivariate curve resolution-alternating least squares, positive matrix factorization, simplex identification via split augmented Lagrangian and self-modelling mixture analysis) in the estimation of pure component spectra from Raman maps of differently manufactured pharmaceutical tablets. The batches of different technologies differ in the homogeneity level of the active ingredient, thus, the curve resolution methods are tested under different conditions. An empirical approach is shown to determine the number of components present in a sample. The chemometric algorithms are compared regarding the number of detected components, the quality of the resolved spectra and the accuracy of scores (spectral concentrations) compared to those calculated with classical least squares, using the true pure component (reference) spectra. It is demonstrated that using appropriate multivariate methods, Raman chemical imaging can be a useful tool in the non-invasive characterization of unknown (e.g. illegal or counterfeit) pharmaceutical products.     

唇形科植物挥发油化学成分的GC/MS研究

在运用GC/MS技术的基础上采用HELP(直观推导式演进特征投影法)方法研究了九种唇形科植物的化学成分, 并以唇形科植物半枝莲为例详细介绍了HELP的解析过程. 应用总体积积分法测定各成分的相对百分含量. 鉴定出相对共有成分达70余种, 大多数为萜类化合物及其衍生物. 不同的唇形科植物的挥发油化学成分与特征成分有明显差异. 九种药材挥发性成分中均含有桉油精(Eucalyptol, 含量0.10%～1.01%)和芳樟醇(Linalool, 0.11%～3.05%). 利用GC/MS分析法结合化学计量学分辨方法鉴定挥发油化学成分, 比单独使用GC-MS法结果更准确、可靠.