GC Fingerprints Research Articles

Chemometrics analysis of camellia oil authenticity using LF NMR and fatty acid GC fingerprints

Low-field nuclear magnetic resonance (LF NMR) parameters and fatty acid contents, combined with chemometrics, were employed to detect the adulteration of camellia oil (CAO) with various oils, including rapeseed oil (RO), sunflower oil (SSO), sesame oil (SEO), corn oil (COO), rice bran oil (RBO), peanut oil (PEO), palm superolein (PAO), or high oleic-peanut oil (HO-PEO). In principal component analysis (PCA), CAO was characterized by higher levels of C18:1n9 and S22, which differentiates it from other vegetable oils. Partial least squares-discriminant analysis (PLS-DA) revealed robust clustering among CAO and other samples. Adulterated CAO samples, with an adulteration level exceeding 10 %, could be accurately classified, achieving a total discrimination accuracy of over 97.15 %. Notably, when the adulteration rate surpassed 40 %, the recognition accuracy for all samples reached 100 %. The optimized partial least squares (PLS) models, relying on fewer than 18 potential key markers identified by variable importance in projection, demonstrated efficiency and precision in predicting the adulteration levels in CAO.

Analysis of GC × GC fingerprints from medicinal materials using a novel contour detection algorithm: A case of Curcuma wenyujin

This study introduces an innovative contour detection algorithm, PeakCET, designed for rapid and efficient analysis of natural product image fingerprints using comprehensive two-dimensional gas chromatogram (GC × GC). This method innovatively combines contour edge tracking with affinity propagation (AP) clustering for peak detection in GC × GC fingerprints, the first in this field. Contour edge tracking significantly reduces false positives caused by “burr” signals, while AP clustering enhances detection accuracy in the face of false negatives. The efficacy of this approach is demonstrated using three medicinal products derived from Curcuma wenyujin. PeakCET not only performs contour detection but also employs inter-group peak matching and peak-volume percentage calculations to assess the compositional similarities and differences among various samples. Furthermore, this algorithm compares the GC × GC fingerprints of Radix/Rhizoma Curcumae Wenyujin with those of products from different botanical origins. The findings reveal that genetic and geographical factors influence the accumulation of secondary metabolites in various plant tissues. Each sample exhibits unique characteristic components alongside common ones, and variations in content may influence their therapeutic effectiveness. This research establishes a foundational data-set for the quality assessment of Curcuma products and paves the way for the application of computer vision techniques in two-dimensional (2D) fingerprint analysis of GC × GC data.

Establishing an integrated, four-dimensional quality assessment system for traditional Chinese medicine: A case study of Shuanghuanglian oral liquid

The quality of traditional Chinese medicine (TCM) is the premise to ensure its safety and effectiveness in clinical application. In this study, a complete quality control system for four-dimensional fingerprinting of TCM was innovatively constructed based on multiple detection techniques, and the quality of Shuanghuanglian oral liquid (SHL) was evaluated. Electrochemical fingerprinting (ECFP) as an emerging method without pretreatment provides rich and quantifiable information for SHL samples. The first quantitative ECFP of SHL was developed by the B-Z oscillation system. Eight characteristic parameters were analyzed and a good linear relationship was found between the oscillation lifetime and sample volume, by which the calculated values of the added sample volume (VL) showed different fluctuations between samples. What is more, high-performance liquid chromatography five-wavelength fusion fingerprint (HPLC-FWFP), GC fingerprint (GC-FP), and UV quantum fingerprint (UV-QFP) was established. Meanwhile, the purity of the peaks of the HPLC-FWFP was verified by the dual-wavelength absorption coefficient ratio spectrum (DWAR). Equal weighted ratio quantitative fingerprinting method (EWRQFM) was successfully proposed to extract all potential features for the overall quality assessment of the samples. Finally, a comprehensive evaluation strategy was proposed, namely the variation coefficient weighting algorithm (VCWA). The results of qualitative and quantitative evaluation of HPLC-FWFP, GC-FP, electrochemical quantum fingerprints (EC-QFP), and UV-QFP were integrated by this method. The established evaluation system is also a suitable strategy to control the quality of other TCM preparations.

Comprehensive quality evaluation of Qizhi Xiangfu Pills based on Quantitative Analysis of Multi-components by Single Marker combining with GC Fingerprint and Chemometrics.

Qizhi Xiangfu Pills (QXPs) is a traditional Chinese medicine (TCM) used clinically for Qi stagnation and blood stasis. The current quality control of QXPs in the ministry standards and the reported literature is minimal, and requires to be improved. This study aimed to analyze and determine the active ingredients in QXPs for its overall evaluation. In this study, a quantitative analysis of multi-components by single marker (QAMS) method was established to simultaneously determine the caryophyllene oxide, cyperotundone, ligustilide and α-cyperone in QXPs by GC. Moreover, the GC fingerprints of 22 batches samples were also established, and the common peaks were initially identified by GC-MS, then classified in various dimensions using chemometric methods, and the main markers causing the discrepancies between groups were analyzed by orthogonal partial least squares discrimination analysis (OPLS-DA). Compared with internal standard method (ISM), the determination results obtained by QAMS had no significant difference. 22 common peaks were distinguished in the fingerprint of 22 batches QXPs, 17 of which were identified, and the similarity of the fingerprint was greater than 0.898. The 22 batches of QXPs were roughly divided into 3 categories, and 12 main markers causing the discrepancy were discovered. The established QAMS combined with GC fingerprint and chemometrics method is convenient and feasible, which helps to improve the quality evaluation of QXPs and provides a demonstration for the relative study of compound preparations and single herbs. A quantitative analysis of multi-components by single marker combining with GC fingerprint and chemometrics method was established to evaluation the quality of Qizhi Xiangfu Pills for the first time.

Development of image similarity strategy based on targeted filtration for non-targeted HS-SPME/GC × GC fingerprints of volatile oils from Chinese patent medicines: A case of Chaihu Shugan Wan

To evaluate Chinese patent medicines more comprehensively, image similarity strategy based on targeted filtration was developed for non-targeted two-dimensional (2D) chromatographic fingerprints of volatile oil fraction in this paper. At first, volatiles and semi-volatiles were enriched from Chaihu Shugan Wan (CSW) by head space- solid phase micro-extraction (HS-SPME), and analyzed by comprehensive two-dimensional gas chromatography (HS-SPME-GC × GC). In succession, the inter-group and intra-group differences were distinguished by multi-component spectral correlative chromatography (MSCC). Facing the challenge of data complexity, some 50 contours were selected to indicate various medicinal materials through zone- specific ion filtration in 2D fingerprints. Among them, the known compounds were proven to be effective in “soothing liver-qi stagnation” through PubChem and other bioinformatic tools. Thirdly, Speeded Up Robust Features- Fast Library for Approximate Nearest Neighbors (SURF-FLANN) algorithm was utilized to estimate the pairwise similarities for the simplified fingerprints. In this procedure, the methodological examination was further made through the simulated images, including comparison with other algorithms, consideration for image complexity, and calculation of positives / negatives. At last, the similarities of six sample fingerprints were scored successfully. In summary, image similarity strategy based on zone- specific ion filtration can provide a viable solution for rapidly evaluating 2D fingerprints of extract fractions from Chinese patent medicines.

Dual control system for comprehensive evaluation of quality consistency of herbal preparations

This study was undertaken to establish an integrated quality control method based on the fingerprint of different testing instruments and a four-dimensional antioxidant activity profile. Firstly, the comprehensive ratio quantitative fingerprint method was used to rapidly calculate the similarity of GC fingerprint, UV-vis quantized fingerprint, HPLC fingerprint and ATR-FT-IR quantized fingerprint. In addition, a comprehensive evaluation strategy was proposed using the variation coefficient weighting algorithm, incorporating four complementary inputs, to achieve highly accurate analysis. At the same time, multi-markers assay by monolinear method was used for the first time for the quantitative analysis of multiple components. Based on this, the fingerprint-efficacy relationship was investigated, and substances that might be biologically active and the wavelength range of their distribution were predicted using the online-HPLC-DPPH-FIA method in conjunction with a PLS model built from individual and combined data matrices. The results showed that all 20 batches of samples were within 1–3 grades, with good quality consistency. According to index E, the samples' overall antioxidant capacity was also highly correlated with the year of production. The four-dimensional antioxidant activity profile also led to the conclusion that variations in antioxidant characteristics were caused by differences in the concentration and volatility of particular bioactive chemicals. Finally, mid-level data fusion produced better classification results than a single technique, further demonstrating the synergistic effects that may occur when the four types of data were combined. This study demonstrated that the combination of GC, UV–vis, ATR-FT-IR and HPLC can be used for the consistency control of herbal preparations and can elucidate the potential in predicting the antioxidant capacity of herbal preparations.

Fingerprint and relationship composition-antioxidant activity of the essential oil of Saccocalyx satureioides Coss. & Dur

Saccocalyx satureioides Coss. & Dur. is an endemic Algerian plant species growing in pre-desert area. The aerial parts are commonly used in the folk medicine. The fingerprint of the aerial part of S. satureioides essential oil (EO) collected periodically at different growing stages was established by GC and GC/MS analyses. Besides, the seasonal variations of the EO components were also investigated. In order to highlight the effect of seasonal variation/variability of the EO composition on the fingerprint pattern, chemometrics methods including principal component analysis (PCA) and heatmap associated with hierarchical clustering analysis (HCA) were applied. The antioxidant activity of the EO was measured using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) assays. The relationship between GC fingerprint and antioxidant activity named spectrum-effect relationship was investigated by partial least squares (PLS) regression. The EO fingerprint was essentially marked by the three major oxygenated monoterpenes which were α-terpineol (34.48–42.43%), borneol (15.24–23.37%) and thymol (19.27–26.96%). Successfully, multivariate models were developed to relate the antioxidant activities responses to the EO chemical composition.

Detection of camellia oil adulteration using chemometrics based on fatty acids GC fingerprints and phytosterols GC–MS fingerprints

The fatty acid, squalene, and phytosterols, coupled to chemometrics were utilized to detect the adulteration of camellia oil (CAO) with palm superolein (PAO), refined olive oil (ROO), high oleic- sunflower oil (HO-SUO), sunflower oil (SUO), corn oil (COO), rice bran oil (RBO), rice oil (RIO), peanut oil (PEO), sesame oil (SEO), soybean oil (SOO), and rapeseed oil (RAO). CAO was characterized with higher triterpene alcohols, thus differentiated from other vegetable oils in principle component analysis (PCA). Using partial least squares-discriminant analysis (PLS-DA), CAO adulterated with PAO, ROO, HO-SUO, SUO, COO, RBO, RIO, PEO, SEO, SOO, RAO (5%–100%, w/w), could be classified, especially higher than 92.31% of the total discrimination accuracy, at an adulterated ratio above 30%. With less than 22 potential key markers selected by the variable importance in projection (VIP), the optimized PLS models were confirmed to be accurate for the adulterated level prediction in CAO.

Oil-Source Rock Correlation Of Oil Seepage And Rock Samples Collected From The Cibulakan Formation At Palimanan Area, West Java

This paper presents the results and discussion of a petroleum geochemistry study performed on two oil seepage and seven outcrop samples collected from the Cibulakan Formation at Palimanan area, West Java. The presence of two oil seepages in Palimanan area indicates that there is an effective source rock which has produces hydrocarbon. The objectives of the study were to determine the hydrocarbon source potential of outcrops, and to characterise selected rock extracts and oil seepage samples, and determine the progenitor source facies at time generation/expulsion. The method used in this research is field study and laboratory analysis. Field studies were conducted on oil and rock sampling, while the geochemical laboratory analysis includes Total Organic Carbon, Rock-Eval Pyrolysis, Vitrinite Reflectance, Kerogen Typing, Bitumen Extraction, Liquid Chromatography, Gas Chromatography fingerprint and GC-MS biomarker. The oil-source rock correlation to its oil based on GC fingerprint (n-alkane distributions) and GC-MS biomarker (triterpanes and sterane distributions) has been done. The oil seepage is correlated with possible source rocks from the Cibulakan Formation. Based on the n-alkane distribution the oil seepage showed biodegradation, but based on the biomarker distributions, it is interpreted that the oil seepage have been generated from a source rock facies containing mainly non-marine algal debris (Type II Kerogen) mixed with some input from terrestrial higher plant organic matter (Type III Kerogen). The oil seepage shows a moderately good correlation with the rock extracts based on GC-MS biomarker data. These biomarker parameters has been successfully used to determine the origin of oil with its precursor source rock by correlating the rock extracts to possible source rocks in the oil and gas exploration.

Discrimination and classification of extra virgin olive oil using a chemometric approach based on TMS-4,4′-desmetylsterols GC(FID) fingerprints of edible vegetable oils

A single out-line HPLC-GC (FID) analytical method is applied to acquire the chromatographic fingerprint characteristic of the TMS-4,4′-desmetylsterol derivative fraction of several marketed edible vegetable oils in order to identify and discriminate the most valuable extra-virgin olive oils from the other vegetal oils (canola, corn, grape seed, linseed, olive pomace, peanut, rapeseed, soybean, sesame, seeds (non-specified composition but usually a blend of corn and sunflower) and sunflower). The natural structure of the preprocessed data undergoes a preliminary exploration using principal component analysis and heat map-based cluster analysis. A partial least squares-discriminant model is first trained from 53 oil samples (only 3 latent variables) and externally validated from 18 test oil samples. No classification errors are found and all the test samples are correctly classified. Additional classification models are also built in order to discriminate among vegetables-oil families and excellent results have been also achieved.

Multiple fingerprinting analyses in quality control of Cassiae Semen polysaccharides

Quality control issue overshadows potential health benefits of Cassiae Semen due to the analytic limitations. In this study, multiple-fingerprint analysis integrated with several chemometrics was performed to assess the polysaccharide quality of Cassiae Semen harvested from different locations. FT-IR, HPLC, and GC fingerprints of polysaccharide extracts from the authentic source were established as standard profiles, applying to assess the quality of foreign sources. Analyses of FT-IR fingerprints of polysaccharide extracts using either Pearson correlation analysis or principal component analysis (PCA), or HPLC fingerprints of partially hydrolyzed polysaccharides with PCA, distinguished the foreign sources from the authentic source. However, HPLC or GC fingerprints of completely hydrolyzed polysaccharides couldn't identify all foreign sources and the methodology using GC is quite limited in determining the monosaccharide composition. This indicates that FT-IR/HPLC fingerprints of non/partially-hydrolyzed polysaccharides, respectively, accompanied by multiple chemometrics methods, might be potentially applied in detecting and differentiating sources of Cassiae Semen.

Authentication and Nutritional Benefits of Cheeses Based on Vegetable Oils

The fatty acid profile of a number of commercial fermented cheeses, based on vegetable oils or milk lipids have been evaluated by GC-FID (gas chromatography with flame ionization detector), disclosing the quantity of SFAs (saturated fatty acids), MUFAs (monounsaturated fatty acids) and PUFAs (polyunsaturated fatty acids), as well as the presence of small quantities of TUFAs (trans unsaturated fatty acids) in the dairy products. The authentication of the cheeses based on vegetable oil or milk was performed by GC or IR fingerprinting.

Biostimulation of spent engine oil contaminated soil using Ananas comosus and Solanum tuberosum peels

This paper presents an assessment of biostimulation potential of A. comosus and Solanum tuberosum peels in soils contaminated with spent engine oil. Microcosms bioreactors containing the spent engine contaminated soil and the peels were set up and monitored for 49 days. The extents of disappearance of the spent engine oil were determined by analyzing the contaminated soils using gas chromatography (GC) coupled with mass spectrometry. Dominant bacteria species were isolated, characterized and tested for their biodegradation potential on different hydrocarbons. Increases in optical density (OD) fluxes and reduction in pH implied that the bacteria species utilized the hydrocarbons optimally. Microscopic examination, physiological tests and comparison to the standard reference organisms, identified the bacteria as members of Arthrobacter, Bacillus and Pseudomonas species. The results from GC-finger prints showed that the biostimulants (A. comosus and S. tuberosum) peels resulted in the disappearance of major aliphatic and aromatic hydrocarbons within the contaminated soil.

HPLC/DAD, GC/MS and GC/GC/TOF analysis of Lemon balm (Melissa officinalis L.) sample as standarlized raw material for food and nutraceutical uses

Melissa officinalis L., commonly known as lemon balm, is a perennial herb belonging to Lamiaceae family. Traditionally administered in infusion form, it has therapeutic properties, such as sedative, carminative and antispasmodic, but also it is used for treatment of headache, rheumatism, indigestion and hypersensitivities. Lemon balm has a complex chemical composition. The aim of this work was the comprehensive characterization of secondary metabolites of a dried Lemon balm (Melissa officinalis L.) sample, through HPLC/DAD, GC/MS and GC/GC/TOF analysis, as raw material for the standardized phyto-complexes production useful for food and nutraceutical application. This sample contained rosmarinic acid (caffeic acid dimer) as the main compound of phenolic fraction (32.4 mg g-1). Citronellal was the most abundant compound in the volatile fraction, followed by α-citral and β-caryophyllene. The total citral amount, in terms of sum of α- and β-citral, was 149.4 mgcitral kg-1. Comprehensive two-dimensional GC fingerprint analysis of lemon balm produced rationalized peak patterns for up to 200 volatile compounds.

Acclimatization of Lemongrass Cultivation in Agro-climatic Conditions of Uttarakhand

The global demand for lemongrass oil is increasing tremendously due to high citral content. In order to study the acclimatization of lemongrass cultivation with respect to citral content in the agroclimatic conditions of a Himalayan state i.e. Uttarakhand (India), a total 132 essential oil samples were collected from different farmers’ fields of Uttarakhand during six years (2009-2014) and subjected to GC fingerprinting for citral estimation. A total 22 samples were analyzed in each year and it has been observed that the mean citral content steadily increased from 69.1 to 78.7% during six years. In the year 2009 and 2010, most of the oil samples (77 and 82%, respectively) showed citral content between 60.0-72.0%. In 2011, 50% of the samples have shown an increased range of citral (72.1-76.0%). Similarly, during 2012 and 2013, more than 68% samples constituted 72.1-76.0% citral in the oils; while in the year 2014, citral content has increased in the lemongrass crop and most of the oil samples (86%) shown citral more than 76.0%. The increasing citral content during six years showed that lemongrass crop is being gradually acclimatized with respect to citral content in the agro-climatic conditions of Uttarakhand.

Characterization of tar-like material and producible oil in Misoa C2 and C3 reservoir sands of the Area 2 South (Ceuta Field, Venezuela)

Here we characterized asphaltic oil occurrences in the Misoa C2 and C3 reservoirs within Area 2 South of the Ceuta Field (Lake Maracaibo Basin, NW Venezuela). To perform the geochemical and petrological characterization of the C2 and C3 sub-units, which cover an interval in which tar-like material was detected, we analyzed core (18) and cutting (123) samples using the Rock-Eval 6 technique in reservoir mode. Samples were studied under fluorescence light and scanning electron microscopy (SEM), showing the presence of two charges of oils and the relationships within silica cements and clay minerals. To evaluate vertical inter-reservoir communication and lateral intra-reservoir continuity, we also studied 12 oil samples from wells in Area 2 South. Biomarkers and isotopic signatures were examined using gas chromatography-mass spectrometry (GC-MS) and isotope ratio mass spectrometry (IRMS). The results suggest that oil and core extracts belongs to a single family derived from two pulses of hydrocarbon generation from the La Luna source rock, which was deposited in a marine reducing environment. The oil samples are a mixture of a paleobiodegraded oil charge and a later fresh, more mature oil recharge. The geochemical analyses also evidence that the formation of heavy oil tar zones can be related to biodegradation and in-reservoir oil mixing, though other formation mechanisms for the tar are also feasible. Finally, the GC fingerprints of the oils are indicative of lateral reservoir continuities across the F-1 and F-2 faults and vertical communication between the Misoa C2 and C3 sub-units in Area 2 South, suggesting that tar occurrences do not act as permeability barriers within the two reservoirs studied.

Biodegradation and Water Washing Effect on Gasoline Range Hydrocarbons and Quality of Crude Oils from HJN and MKM Fields of Upper Assam Basin, India

Abstract: The crude oils from Oligocene and Miocene formation of upper Assam basin have moderate API gravity and significant wax content. Crude oils from HJN and MKM fields of upper Assam basin are being produced from Oligocene and Miocene sands. These oils are somewhat biodegraded in nature as evidenced from their API gravity, density, bulk composition, GC fingerprints and relative concentrations of compounds in the gasoline range. It is observed from whole oil gas chromatographic data that the lighter hydrocarbons are more effected as a result of biodegradation and water washing than the heavier components. In the gasoline range compounds highest degradation of n-alkanes are observed followed by iso- and cyclo-alkanes. The extent of the effect of biodegradation of the gasoline range compounds in crude oil samples cannot be illustrated by the concentrations of the compounds. The concentrations only describe qualitative differences in molecular composition. This difficulty can be overcome by using parameters called degradative loss (%). This parameter shows exactly how much loss or gain has taken place in the gasoline range compounds. Within the gasoline range compounds, n-alkanes, Benzene baring HJN 15 and MKM 14 and Toluene experienced degradative loss indicating effects of both biodegradation and water washing in these oils. Cyclo-alkanes are least effected by biodegradation followed by iso-alkanes in all the oils. The extent of biodegradation and water washing is different for each oils from HJN and MKM fields as indicated by the degradative loss (%) of the compounds in the gasoline range.

Intra- and inter-field compositional changes of oils from the Misoa B4 reservoir in the Ceuta Southeast Area (Lake Maracaibo, Venezuela)

Here we analyzed oil samples from 35 wells in the Ceuta Southeast Area (Lake Maracaibo Basin, northwestern Venezuela) in order to evaluate lateral intra-reservoir continuity in the Misoa B4 unit. Biomarkers, isotopic signature, and also V and Ni were examined using gas chromatography–mass spectrometry (GC–MS), isotope ratio mass spectrometry (IRMS), and inductively-coupled plasma atomic emission spectroscopy (ICP-AES). Multivariate statistical analysis was also applied to obtain useful information from geochemical data. On the basis of the characterization of these samples, we conclude that they all fall into various oil families derived from two pulses of hydrocarbon generation, migration and accumulation from the calcareous La Luna source rock, deposited in an anoxic marine environment under reducing conditions. Thus, these oils are a mixture of an earlier biodegraded, less mature oil charge and a later fresh non-biodegraded oil recharge. In addition, we applied asphaltene pyrolysis to one (LG-62) of the three “anomalous” oils. The LG-62 sample was confirmed as an almost “pure” paleobiodegraded end-member, whereas the VLF-3020 oil was tentatively classified as the unaltered end-member oil-type. Finally, the GC fingerprints and Fourier Transform Infra Red (FTIR) spectroscopic indices of the oils were used to detect minor variations in composition that are indicative of reservoir compartmentalization.

A New Method of Testing and Evaluating the Quality of Refined Montan Wax: Digital Color and GC Fingerprint

To establish a new method of testing and evaluating the quality of refined montan wax (RMW), digital color and GC fingerprint technology were introduced and applied. CIE Lab color mode was used to digitize the exterior colors of RMW, and the score obtained through a fitting function was also used to reflect its quality. It is shown that they were in complete accord with the human visual perception trend. The GC fingerprint was used to characterize the internal chemical information of RMW, and the composition of its internal features was reflected through the relative retention time (RRT) and relative peak area (RPA) values. It is shown that there was a high degree of similarity between the fingerprints, while certain differences also existed. This can be used to implement effective application of RMW to aspects such as quality control, adulteration identification, and origin attributions.

Spectrum–effect relationships between GC fingerprints and anti-liver injury activities of fatty oil from Herpetospermum caudigerum

Spectrum–effect relationships between GC fingerprints and anti-liver injury activities of fatty oil from Herpetospermum caudigerum