Investigation on Tissue Sample Stability by Ambient Mass Spectrometry Imaging Method

KeyWord:airflow assisted ionization£¨AFAI£©  ambient mass spectrometry imaging£¨AMSI£©  sample stability  medicines  endogenous metabolites

Abstract:

      Key parameters of air flow assisted ionization mass spectrometry imaging£¨AFAI-MSI£© system were investigated and optimized by using tissue sections adding homogeneous NHBA as the target samples.The parameters£¬including those related with spray solvent£¬spray gas£¬as well as geometric setting of AFAI system were optimized. Based on the optimization£¬stability of endogenous metabolites from the tissue section was also taken into consideration during the AFAI-MSI experiment.It usually takes 7-8 h for a complete MSI experiment for a whole-body tissue section£¬and the stability of endogenous metabolites needs to be investigated during such a long process. Therefore£¬a whole-body tissue section was imaged twice consecutively£¬and then the data of resulted images were compared using visualized component principle analysis£¨PCA£© after selecting main mass spectra peaks.By visualized comparing of the result£¬the similarity of the visualized PCA score plot demonstrated the endogenous metabolites were stable during MSI experiment.In conclusion£¬the optimized parameters guaranteed the stability and sensitivity of AFAI-MSI experiment.Additionally£¬after proper sample pretreatment£¬the endogenous metabolites in tissue sections were able to remain stable during the AFAI-MSI experiment£¬which ensured the reliability for research of the variability of endogenous metabolites.Thus the AFAI-MSI method is promising to be applied in the study of drug development.