A serious problem in secondary ion mass spectrometry (SI MS ) analysis is its “matrix effect” that hinders the quantification of a certain species in a sample and consequently, appropriate corrective measures are ta...A serious problem in secondary ion mass spectrometry (SI MS ) analysis is its “matrix effect” that hinders the quantification of a certain species in a sample and consequently, appropriate corrective measures are taken to calibrate the secondary ion currents into respective concentrations for accu rate compositional analysis. Use of “calibration standards” is necessary for t his purpose. Detection of molecular MCs_n+ ions (M-element to be analyz ed , n=1, 2, 3,….) under Cs+ ion bombardment is a possible mean to minimiz e such matrix effect, enabling one to quantify without the need of calibration sta ndards. Our recent studies on MCs_n+ molecular ions aim towards the understanding of their formation mechanisms, which are important to know their e ffects on SIMS quantification. In-depth quantitative analysis is a major strength of SIMS for which ‘depth resolution’ is of significant relevance. The optimal choice of the impact pa rameters during SIMS analyses can play an effective role in obtaining data with ultra-high depth resolution. SIMS is possible at depth resolution in the nm or even sub-nm rang e, with quantifiable data obtained from the top monolayer onwards into the material. Wi th optimized experimental conditions, like extremely low beam current (down to ～10 nA), and low bombarding energy (below 1 keV), ultra-high depth resolution SIMS has e nabled interfacial composition analysis of ultra-thin films, quantum wells, heterostru ctures, etc. and complex low-dimensional structures with high precision and re peatability.展开更多
Gas chromatographymass spectrometry (GC-MS) coupled with chemometric resolution upon two- dimensional data was employed to analyze the constituents of essential oils of Angelica sinensis. Constituents in essential oil...Gas chromatographymass spectrometry (GC-MS) coupled with chemometric resolution upon two- dimensional data was employed to analyze the constituents of essential oils of Angelica sinensis. Constituents in essential oils of Angelica sinensis root were identified by GC-MS with the help of subwindow factor analysis (SFA) method resolving two-dimensional original data into mass spectra and chromatograms. 76 of 97 separated constituents in essential oil of Angelica sinensis root were identified and quantified, and they account for about 91.36% of the total content. The results show that ligustilide, butylene phthalide, 2-methoxy-4-vinylphenol, carvacrol, allo-ocimene,2,6,6-trimethylbicyclo-[3,1,1]hept-2-ene are the main constituents in essential oil of Angelica sinensis root.展开更多
The volatile chemical components of Radix Paeoniae Rubra (RPR) were analyzed by gas chromatography-mass spectrometry with the method of heuristic evolving latent projections and overall volume integration. The results...The volatile chemical components of Radix Paeoniae Rubra (RPR) were analyzed by gas chromatography-mass spectrometry with the method of heuristic evolving latent projections and overall volume integration. The results show that 38 volatile chemical components of RPR are determined, accounting for 95.21% of total contents of volatile chemical components of RPR. The main volatile chemical components of RPR are (Z, Z)-9,12-octadecadienoic acid, n-hexadecanoic acid, 2-hydroxy- benzaldehyde, 1-(2-hydroxy-4-methoxyphenyl)-ethanone, 6,6-dimethyl-bicyclo[3.1.1] heptane-2-methanol, 4,7-dimethyl-benzofuran, 4-(1-methylethenyl)-1-cyclohexene-1-carboxaldehyde, and cyclohexadecane.展开更多
文摘A serious problem in secondary ion mass spectrometry (SI MS ) analysis is its “matrix effect” that hinders the quantification of a certain species in a sample and consequently, appropriate corrective measures are taken to calibrate the secondary ion currents into respective concentrations for accu rate compositional analysis. Use of “calibration standards” is necessary for t his purpose. Detection of molecular MCs_n+ ions (M-element to be analyz ed , n=1, 2, 3,….) under Cs+ ion bombardment is a possible mean to minimiz e such matrix effect, enabling one to quantify without the need of calibration sta ndards. Our recent studies on MCs_n+ molecular ions aim towards the understanding of their formation mechanisms, which are important to know their e ffects on SIMS quantification. In-depth quantitative analysis is a major strength of SIMS for which ‘depth resolution’ is of significant relevance. The optimal choice of the impact pa rameters during SIMS analyses can play an effective role in obtaining data with ultra-high depth resolution. SIMS is possible at depth resolution in the nm or even sub-nm rang e, with quantifiable data obtained from the top monolayer onwards into the material. Wi th optimized experimental conditions, like extremely low beam current (down to ～10 nA), and low bombarding energy (below 1 keV), ultra-high depth resolution SIMS has e nabled interfacial composition analysis of ultra-thin films, quantum wells, heterostru ctures, etc. and complex low-dimensional structures with high precision and re peatability.
文摘Gas chromatographymass spectrometry (GC-MS) coupled with chemometric resolution upon two- dimensional data was employed to analyze the constituents of essential oils of Angelica sinensis. Constituents in essential oils of Angelica sinensis root were identified by GC-MS with the help of subwindow factor analysis (SFA) method resolving two-dimensional original data into mass spectra and chromatograms. 76 of 97 separated constituents in essential oil of Angelica sinensis root were identified and quantified, and they account for about 91.36% of the total content. The results show that ligustilide, butylene phthalide, 2-methoxy-4-vinylphenol, carvacrol, allo-ocimene,2,6,6-trimethylbicyclo-[3,1,1]hept-2-ene are the main constituents in essential oil of Angelica sinensis root.
基金Project(20235020) supported by the National Natural Science Foundation of China
文摘The volatile chemical components of Radix Paeoniae Rubra (RPR) were analyzed by gas chromatography-mass spectrometry with the method of heuristic evolving latent projections and overall volume integration. The results show that 38 volatile chemical components of RPR are determined, accounting for 95.21% of total contents of volatile chemical components of RPR. The main volatile chemical components of RPR are (Z, Z)-9,12-octadecadienoic acid, n-hexadecanoic acid, 2-hydroxy- benzaldehyde, 1-(2-hydroxy-4-methoxyphenyl)-ethanone, 6,6-dimethyl-bicyclo[3.1.1] heptane-2-methanol, 4,7-dimethyl-benzofuran, 4-(1-methylethenyl)-1-cyclohexene-1-carboxaldehyde, and cyclohexadecane.
