[Objectives] To analyze the low melting point fat constituents in the black soybeans with green and yellow heart and their relative content,and compare the differences in the low melting point fat constituents between...[Objectives] To analyze the low melting point fat constituents in the black soybeans with green and yellow heart and their relative content,and compare the differences in the low melting point fat constituents between different kinds of black soybeans. [Methods] Using HS-SPME-GC-MS,the qualitative analysis was performed on the low melting point fat constituents of black soybeans; using peak area normalization method,the relative content of constituents was calculated. [Results]A total of 42 peaks were identified from the low melting point fat constituents of the black soybeans with yellow heart,and 18 kinds of chemical constituents were identified,accounting for 81.39% of total relative content of low melting point fat constituents; a total of 37 peaks were identified from the low melting point fat constituents of the black soybeans with green heart,and 15 kinds of chemical constituents were identified,accounting for 83.24% of total relative content of low melting point fat constituents. There were 9 kinds of common chemical constituents for the two kinds of black soybeans,and 5-allylguaiacol had the highest relative content,followed by hexanol. [Conclusions] There was no significant difference in the low melting point fat constituents between two kinds of black soybeans.展开更多
The molecular transformations of carboxylic acids in heavy acidic SL crude before and after true boiling point distillation were examined by ultra-high resolution negative-ion electrospray ionization(ESI) Fourier tran...The molecular transformations of carboxylic acids in heavy acidic SL crude before and after true boiling point distillation were examined by ultra-high resolution negative-ion electrospray ionization(ESI) Fourier transform ion cyclotron resonance mass spectrometry(FT-ICR MS). The acid class(heteroatom number), type(z numbers) and carbon number distributions were positively characterized. It was found out that the total acid number(TAN) of SL crude decreased after true boiling point distillation, and the abundance of O2 class in mass spectra was also found to be reduced from 67.6% to 34.5% in SL TBP mixed crude as measured by MS spectra, indicating to a potential carboxylic acid decomposition. However, it was interesting that the carboxylic acids type distribution in both oils was almost the same although their relative abundance in SL TBP mixed crude turned to be much lower, suggesting that various petroleum carboxylic acid types have the similar thermal decomposition reaction behavior. Furthermore, for each O2 type of acids in SL TBP mixed crude, the abundance of carboxylic acids with carbon number higher than 35 was reduced greatly, especially for those with carbon number higher than 60, the mass peaks of which were nearly totally removed, indicating that the large carboxylic acid molecules in heavy fractions decomposed more significantly because of longer heating time during the true boiling point distillation process. As a result, the reduction of TAN may be caused by the thermal decomposition of carboxylic acids especially those with high carbon number, suggesting that quick distillation or much lower pressure is required to avoid the thermal decomposition.展开更多
文摘[Objectives] To analyze the low melting point fat constituents in the black soybeans with green and yellow heart and their relative content,and compare the differences in the low melting point fat constituents between different kinds of black soybeans. [Methods] Using HS-SPME-GC-MS,the qualitative analysis was performed on the low melting point fat constituents of black soybeans; using peak area normalization method,the relative content of constituents was calculated. [Results]A total of 42 peaks were identified from the low melting point fat constituents of the black soybeans with yellow heart,and 18 kinds of chemical constituents were identified,accounting for 81.39% of total relative content of low melting point fat constituents; a total of 37 peaks were identified from the low melting point fat constituents of the black soybeans with green heart,and 15 kinds of chemical constituents were identified,accounting for 83.24% of total relative content of low melting point fat constituents. There were 9 kinds of common chemical constituents for the two kinds of black soybeans,and 5-allylguaiacol had the highest relative content,followed by hexanol. [Conclusions] There was no significant difference in the low melting point fat constituents between two kinds of black soybeans.
基金financially supported by the National Key Basic Research Development Program "973" Project (2006CB202501)
文摘The molecular transformations of carboxylic acids in heavy acidic SL crude before and after true boiling point distillation were examined by ultra-high resolution negative-ion electrospray ionization(ESI) Fourier transform ion cyclotron resonance mass spectrometry(FT-ICR MS). The acid class(heteroatom number), type(z numbers) and carbon number distributions were positively characterized. It was found out that the total acid number(TAN) of SL crude decreased after true boiling point distillation, and the abundance of O2 class in mass spectra was also found to be reduced from 67.6% to 34.5% in SL TBP mixed crude as measured by MS spectra, indicating to a potential carboxylic acid decomposition. However, it was interesting that the carboxylic acids type distribution in both oils was almost the same although their relative abundance in SL TBP mixed crude turned to be much lower, suggesting that various petroleum carboxylic acid types have the similar thermal decomposition reaction behavior. Furthermore, for each O2 type of acids in SL TBP mixed crude, the abundance of carboxylic acids with carbon number higher than 35 was reduced greatly, especially for those with carbon number higher than 60, the mass peaks of which were nearly totally removed, indicating that the large carboxylic acid molecules in heavy fractions decomposed more significantly because of longer heating time during the true boiling point distillation process. As a result, the reduction of TAN may be caused by the thermal decomposition of carboxylic acids especially those with high carbon number, suggesting that quick distillation or much lower pressure is required to avoid the thermal decomposition.
