ABSTRACT
Traditional Chinese medicines (TCMs) possess a rich historical background, unique theoretical framework, remarkable therapeutic efficacy, and abundant resources. However, the modernization and internationalization of TCMs have faced significant obstacles due to their diverse ingredients and unknown mechanisms. To gain deeper insights into the phytochemicals and ensure the quality control of TCMs, there is an urgent need to enhance analytical techniques. Currently, two-dimensional (2D) chromatography, which incorporates two independent separation mechanisms, demonstrates superior separation capabilities compared to the traditional one-dimensional (1D) separation system when analyzing TCMs samples. Over the past decade, new techniques have been continuously developed to gain actionable insights from complex samples. This review presents the recent advancements in the application of multidimensional chromatography for the quality evaluation of TCMs, encompassing 2D-gas chromatography (GC), 2D-liquid chromatography (LC), as well as emerging three-dimensional (3D)-GC, 3D-LC, and their associated data-processing approaches. These studies highlight the promising potential of multidimensional chromatographic separation for future phytochemical analysis. Nevertheless, the increased separation capability has resulted in higher-order data sets and greater demands for data-processing tools. Considering that multidimensional chromatography is still a relatively nascent research field, further hardware enhancements and the implementation of chemometric methods are necessary to foster its robust development.
ABSTRACT
A method of qualitative and quantitative analysis on fluid catalytic cracking (FCC) full range gasoline by comprehensive two-dimensional gas chromatography coupled with time-of-flight mass spectrometry (GC×GC-TOF MS) was established. The results showed that paraffins, olefins, naphthenes and aromatics in FCC gasoline had regional and zonal distribution in two-dimensional contour plots. The distinctions of boiling points and polarity between different compounds were used to achieve the accurate separation and determination in GC×GC-TOF MS analysis, and consequently the co-current flow which was often present in the conventional GC analysis was greatly suppressed. The difference of ionizing efficiency between different compounds was modified by response factors, and moreover, a good quantitative dependency was found between the analysis results of GC and GC×GC-TOF MS on FCC gasoline. Due to the high separation resolution, GC×GC-TOF MS gave more accurate results about the group compositions of FCC gasoline. GC×GC-TOF MS provided an effective way with high precision for the characterization of FCC gasoline.
ABSTRACT
<p><b>OBJECTIVE</b>To investigate the chemical transformation of volatile compounds in sulfur-fumigated Radix Angelicae Sinensis.</p><p><b>METHODS</b>A comprehensive two-dimensional gas chromatography (GC×GC) and high-resolution time-of-flight mass spectrometry (HR-TOF/MS) with colorized fuzzy difference (CFD) method was used to investigate the effect of sulfur-fumigation on the volatile components from Radix Angelicae Sinensis.</p><p><b>RESULTS</b>Twenty-five compounds that were found in sun-dried samples disappeared in sulfur-fumigated samples. Seventeen volatile components including two sulfur-containing compounds were newly generated for the first time in volatile oils of sulfur-fumigated Radix Angelicae Sinensis.</p><p><b>CONCLUSION</b>The strategy can be successfully applied to rapidly and holistically discriminate sun-dried and sulfur-fumigated Radix Angelicae Sinensis. GC×GC-HR-TOF/MS based CFD is a powerful and feasible approach for the global quality evaluation of Radix Angelicae Sinensis as well as other herbal medicines.</p>
Subject(s)
Color , Drugs, Chinese Herbal , Fumigation , Fuzzy Logic , Gas Chromatography-Mass Spectrometry , Methods , Oils, Volatile , Reference Standards , Sulfur , Volatile Organic CompoundsABSTRACT
A new method for the determination of organic acids from mainstream cigarette smoke using ultra low temperature solvent extraction-comprehensive two-dimensional gas chromatography/time-of-flight mass spectrometry(GC×GC-TOF/MS)was established. The mainstream smoke was directly trapped by ethyl ether with ultra low temperature solvent extraction device, and cleaned up with liquid-liquid extraction. The concentrated extracts were further derived by N,O-bis(trimethylsily)trifluoroacetamide (BSTFA). The good separation of silanized product was achieved by the column set of DB-1 (30 m × 0. 25 mm, 1. 0 μm) as the 1st column and DB-wax (1. 5 m × 0. 1 mm, 0. 1 μm) as the 2nd column with modulation period of 6 s and scan range of m/z 45-450 . The results showed that linearity correlation coefficients were larger than 0 . 99 , and the average recoveries were between 80. 17% and 107. 81% with the relative standard deviations (RSD) in the range of 0 . 4%-12 . 1% ( n=5 ) . The detection limit and the quantitation limit were 1 . 3-24 . 5 μg/kg and 4. 1-77. 1 μg/kg, respectively.