Ambient Mass Spectrometry For Fast Identification Of Lung Cancer

Objective:Ambient mass spectrometry (AMS) is a recent innovation in mass spectrometrywhich allows recording mass spectra on ordinary samples in their native environment,without sample pretreatment by creating ions outside the instrument. Tip-sprayionization mass spectrometry (TSI-MS) is one of AMS methods. This study appliedTSI-MS to analyze tissue sample of lung cancer and normal lung and to explore theeffect and application of ambient mass spectrometry (AMS) for fast identification oflung cancer.Metholds:Intraoperatively collected cancerous tissue samples and adjacent normal tissuesof lung from15lung cancer patients were analyzed without any pretreatment by ahome-made solvent-assisted tip-spray ionization mass spectrometry. Flow rate ofsolvent (methanol) was4ul/min. Ion source mode was set as follows: positive ionmode, mass range of m/z50-2000, temperature of ion transmission tube as150℃,spray voltage as3.5kV, other parameters were set at default values of instrument andno further optimization was performed. Analyzed mass range was set as m/z750-850.Data of the spectra was analyzed in matlab. Student’s t test was performed to confirmthe significance of some spectra. Principal component analysis (PCA) was used as adata processing method for the fingerprinting spectra.Results:Among mass range of m/z750-850, obvious fingerprint spectra of tissue samplewere observed，such as m/z756.7,772.6、780.7,782.7,808.7,824.7,832.7, etc.. Fromstatistical analyses, spectra at m/z756.7,772.6,780.7,808.7,824.7and832.7showedsignificant differences between cancerous tissue and normal tissue (P <0.01,Student’s t test). Pattern recognitions at the fingerprint spectrum level for clusteringanalysis of tissue samples were achieved successfully with lung cancer separatedfrom normal ones．Conclusions: Coupling with PCA analysis, the cancerous tissue samples of NSCLC can beidentified effectively from the adjacent normal tissue by AMS, which may havepotential application in fast diagnosis and tumor biomarker research of lung cancer.