Amino acids are very important compounds for the body and are involved in important functions that keep us healthy. Amino acids are essential components such as valine, proline, glutamine and glutamic acid. They can b...Amino acids are very important compounds for the body and are involved in important functions that keep us healthy. Amino acids are essential components such as valine, proline, glutamine and glutamic acid. They can be synthesized either naturally or artificially. To examine the metabolism and regulate the synthesis process, compounds labeled with nitrogen or carbon isotopes need to be used. These isotopic compounds allow for more extensive research and enable studies that would otherwise be impossible. However, their use is dependent on the availability of simple, efficient methods for isotopic analysis. Currently, the determination of the atomic fraction of carbon and nitrogen isotopes is only possible through their conversion into molecular nitrogen or carbon monoxide or carbon dioxide. This leads to the loss of information about isotopic enrichment in specific centers of the molecule. This article explores a new direct approach to determining the atomic fraction of carbon and nitrogen isotopes in the isotope-modified or identical centers of these compounds. This method eliminates the transfer process and dilution due to nitrogen and carbon impurities. It is now possible to simultaneously determine the atomic fraction of nitrogen and carbon isotopes in the research substance. This method can be applied to amino acids, making it an effective tool for proposing new research methods. Several articles [1] [2] [3] have proposed similar methods for organic compounds and amino acids.展开更多
The TOF-SIMS fragment peak ascription of organic and inorganic ions of mineral-bituminous groundmass of Jurassic source rocks in the Turpan-Hami and Junggar basins was studied by using the high-resolution Time of Flig...The TOF-SIMS fragment peak ascription of organic and inorganic ions of mineral-bituminous groundmass of Jurassic source rocks in the Turpan-Hami and Junggar basins was studied by using the high-resolution Time of Flight Secondary Ion Mass Spectrometer (TOF-SIMS). The characteristics of spectrum distribution and constitution of fragment ions of the mineral-bituminous groundmass are discussed; then the methods of evaluating its hydrocarbon-generating potential are developed. In addition, the typical parameters, XAL, Yox and ZAR, for indicating the hydrocarbon-generating potential of mineral-bituminous and other organic matter in source rocks are put forward to reflect the aliphatic, oxygenous, and aromatic structures. It is confirmed by Rock-Eval that these parameters are significant in evaluating hydrocarbon generation. Moreover, the detection of the nitrogenous and oxygenous fragment ion, CH5NO3+, in the mudstone formed in semi-deep lakes and in the carbargilite formed in the arms of lakes reflects the fact that microbes take an active part in biologic degradation.展开更多
Twenty-two indole Schiff-base derivatives were synthesized. Two special ways of cleavage were discussed in the formation of the specific fragment ions in the mass spectra(MS).
Tris[o-mercaptophenolato]vanadium(IV)dimer complexes(A)_2[V(mp)_3NaLL']_2(A= Ph_4P^+,H_2mp=o-mercaptophenol,L=MeCN,L'=EtOH,(1);L'=MeOH,(2))were prepared by the reaction of anhydrous VCl_3 and Na_2mp in the...Tris[o-mercaptophenolato]vanadium(IV)dimer complexes(A)_2[V(mp)_3NaLL']_2(A= Ph_4P^+,H_2mp=o-mercaptophenol,L=MeCN,L'=EtOH,(1);L'=MeOH,(2))were prepared by the reaction of anhydrous VCl_3 and Na_2mp in the molar ratio 1:3.Complex(3)(A=Et,N^+,L=L'= MeOH)was prepared by the reaction of VCl_3,Na_2mp and Li_2S in the molar ratio 1:2:1.The com- plexes were characterized by X-ray diffraction crystallography,infrared spectra,magnetic suseepti- bility,and cyclic voltammetric measurements.Complex 2 crystallizes in the triclinic space group P1 with a=12.813(6),b=14.199(4),c=12.790(5),α=112.72(2),β=104.24(4).γ=88.68(4)°,V= 2073.6,and Z=1.The structure was refined to R=0.058.Complex 3 crystallizes in the mono- clinic space group P2_1/n with a=12.359(3),b=17.452(6),c=14.829(13),β=96.51(5)°,V=3177.8, and Z=2.The final R factor is 0.067.Both of the anions of 2 and 3 contain two[V(rap)3]^(2-) fragments linked by sodium ions through the μ_3-O bridges with a crystallographic center of symmetry.The V(IV) atom is in a coordination environment intermediate between a trigonal prism and an ideal octahedron.展开更多
文摘Amino acids are very important compounds for the body and are involved in important functions that keep us healthy. Amino acids are essential components such as valine, proline, glutamine and glutamic acid. They can be synthesized either naturally or artificially. To examine the metabolism and regulate the synthesis process, compounds labeled with nitrogen or carbon isotopes need to be used. These isotopic compounds allow for more extensive research and enable studies that would otherwise be impossible. However, their use is dependent on the availability of simple, efficient methods for isotopic analysis. Currently, the determination of the atomic fraction of carbon and nitrogen isotopes is only possible through their conversion into molecular nitrogen or carbon monoxide or carbon dioxide. This leads to the loss of information about isotopic enrichment in specific centers of the molecule. This article explores a new direct approach to determining the atomic fraction of carbon and nitrogen isotopes in the isotope-modified or identical centers of these compounds. This method eliminates the transfer process and dilution due to nitrogen and carbon impurities. It is now possible to simultaneously determine the atomic fraction of nitrogen and carbon isotopes in the research substance. This method can be applied to amino acids, making it an effective tool for proposing new research methods. Several articles [1] [2] [3] have proposed similar methods for organic compounds and amino acids.
文摘The TOF-SIMS fragment peak ascription of organic and inorganic ions of mineral-bituminous groundmass of Jurassic source rocks in the Turpan-Hami and Junggar basins was studied by using the high-resolution Time of Flight Secondary Ion Mass Spectrometer (TOF-SIMS). The characteristics of spectrum distribution and constitution of fragment ions of the mineral-bituminous groundmass are discussed; then the methods of evaluating its hydrocarbon-generating potential are developed. In addition, the typical parameters, XAL, Yox and ZAR, for indicating the hydrocarbon-generating potential of mineral-bituminous and other organic matter in source rocks are put forward to reflect the aliphatic, oxygenous, and aromatic structures. It is confirmed by Rock-Eval that these parameters are significant in evaluating hydrocarbon generation. Moreover, the detection of the nitrogenous and oxygenous fragment ion, CH5NO3+, in the mudstone formed in semi-deep lakes and in the carbargilite formed in the arms of lakes reflects the fact that microbes take an active part in biologic degradation.
文摘Twenty-two indole Schiff-base derivatives were synthesized. Two special ways of cleavage were discussed in the formation of the specific fragment ions in the mass spectra(MS).
基金Project supported by the National Natural Science Foundation of China,the Natural Science Foundation of Chinese Academy of Sciences and the Natural Science Foundation of Fujian
文摘Tris[o-mercaptophenolato]vanadium(IV)dimer complexes(A)_2[V(mp)_3NaLL']_2(A= Ph_4P^+,H_2mp=o-mercaptophenol,L=MeCN,L'=EtOH,(1);L'=MeOH,(2))were prepared by the reaction of anhydrous VCl_3 and Na_2mp in the molar ratio 1:3.Complex(3)(A=Et,N^+,L=L'= MeOH)was prepared by the reaction of VCl_3,Na_2mp and Li_2S in the molar ratio 1:2:1.The com- plexes were characterized by X-ray diffraction crystallography,infrared spectra,magnetic suseepti- bility,and cyclic voltammetric measurements.Complex 2 crystallizes in the triclinic space group P1 with a=12.813(6),b=14.199(4),c=12.790(5),α=112.72(2),β=104.24(4).γ=88.68(4)°,V= 2073.6,and Z=1.The structure was refined to R=0.058.Complex 3 crystallizes in the mono- clinic space group P2_1/n with a=12.359(3),b=17.452(6),c=14.829(13),β=96.51(5)°,V=3177.8, and Z=2.The final R factor is 0.067.Both of the anions of 2 and 3 contain two[V(rap)3]^(2-) fragments linked by sodium ions through the μ_3-O bridges with a crystallographic center of symmetry.The V(IV) atom is in a coordination environment intermediate between a trigonal prism and an ideal octahedron.
