Abstract A rapid gas chromatographic ( GC ) method was established for the determination of short-chain fatty acids ( SCFAs ) in human feces. Feces samples were directly extracted by 1% HCl-75% ethanol solution, and then centrifuged at high speed for GC analysis. The chromatographic separation was performed on a DB-FFAP capillary column ( 30 m í 0 . 25 mm í 0 . 25 μm ) with a temperature program ( initial temperature at 50℃ held for 1 min, ramped to 190℃ at 10℃/min ) . The injection port temperature was 250℃ with split ratio at 50:1 . The carrier gas was high purity nitrogen with a constant linear velocity at 1. 0 mL/min. A flame ionization detector was employed to quantify SCFAs. The proposed method had been certified by systematic method validation, and used to determine feces samples. Subsequently, the health volunteer and colorectal cancer patient groups could be distinguished successfully by multivariate statistical analysis. Compared with health volunteers, the acetic acid and butyric acid of feces from colorectal cancer patients were reduced obviously, indicating that SCFAs particularly butyric acid could be considered as candidate markers for colorectal cancer diagnosis. In summary, this study provides a rapid method for the determination of SCFAs in feces form health volunteers and colorectal cancer patients. The method had a prospect for screening and diagnosing colorectal cancer rapidly.

A rapid headspace gas chromatography tandem mass spectrometric ( HS-GC/MS ) method was established for the analysis of volatile fatty acids ( VFAs ) in the feces. Feces were suspended by 6%phosphoric acid aqueous solution (1:2 m/V) and sealed in the headspace bottle for HS-GC/MS analysis. The HS-GC/MS method was optimized as follows: agitator temperature ( temp. ):80 ℃, syringe temp.:80 ℃, sample incubation time: 30 min, injection: 1 mL without split-flow. The chromatographic separation was performed on a DB-FFAP capillary column (30m×0. 25 mm×0. 25 μm) with injection port temp.:250 ℃. The temperature program ( initial temp. at 50 ℃ within first 1 min, and raised to 200 ℃ by 10 ℃/min) was employed by fixing the flow of carrier gas (high purity helium) at 1. 0 mL/min. The electron energy at -70 eV for electron impact ( EI ) ionization, ion source temp.: 250 ℃, transfer line temp.:280 ℃, the voltage of electron multiplier at 0. 95 kV. The spectra were recorded in the range of m/z 33-200 for full scan. The established HS-GC/MS method could be applied to analyze VGAs in the feces from human and rat appropriately. There are nine VFAs identified in the feces from human, and eight VFAs detected in the feces from rat by retrieving the NIST library, comparing with the standards and analyzing the MS data. Furthermore, the relative percentage contents of acetic acid, propionic acid and butyric acid accounted for roughly 85% of all VFAs by area normalization. The method is simple and sensitive, and it can be used to rapidly detect VFAs in the feces from human and rat.

Quality control of traditional Chinese medicine is of great importance to ensure its safety and effectiveness in clinic,and is also an obstacle impeding the modernization of traditional Chinese medicine.Though,the complexity of traditional Chinese medicine resulted in some relative weakness of quality standard researches.The critical point need addressing is to establish a sound quality standard system conforming to the characteristics of traditional Chinese medicine in the process of the modernization of Chinese medicine.In this paper,in regard to Dan Hong injection,discriminant strategy of Q-Markers from traditional Chinese medicine injection was clarified from three aspects:what ingredients,which to control and how to control,providing a new vision in the field of the quality standard researches of traditional Chinese medicine.