Experimental Study On Key Technology Of Air Force Assisted Ion Source

In order to realize in-suit and rapid detection without complexpretreatment technology in the field of detecting environment pollution,explosive, drug, chemical warfare agent, clinical medicine, we design andimplement of air flow assisted ionization (AFAI) as a novel and effective,remote sampling method for ambient mass spectrometry which hasindependent intellectual property.On the ground of the chemical analysis principle of the massspectrometry, we design and manufacture an air flow assisted ionizationexperimental platform based on the traditional desorption electrosprayionization (DESI) and atmospheric pressure chemical ionization (APCI),including interface connected to the commercial mass spectrometry,3D highaccuracy of positioning objective table, sample slides, panel box for objectivetable and application program of data collection and conversion for molecularimaging. Besides, the parameter and structure of all parts of theAFAI-DESI-MS or AFAI-APCI-MS are listed in the paper.In order to optimize the performance index of AFAI, we do a lot ofexperiments to achieve curve graphs to prove how to optimize the parameterof the device. We design many different experiments to focus on differentparameters such as the rate of extracting air, the distance between transferpipe and acquisition cone of mass spectrometer, the material of the transferpipe, the high voltage applied on the transfer pipe and funnel, the rate of sprayair and spray solution, spray angle, spray distance and focus voltage. Theresults of AFAI proved that it’s not only an effective way to collect andremote transfer ions, but also promotes ion formation, desorption and evenprevents ions fragmentation during the progress of ionization. Under ambientconditions, the gas flow and atmospheric pressure have significantly influenceon transferring and focusing the ions and improving the sensitivity and resolution of mass spectrum.Non-polar and highly polar molecules, including pharmaceutical samples,dyes, protein, dyes, drugs of abuse, explosive and volatile compounds such asalkane, aldehyde, acid and benzene series have been successfully analyzedusing AFAI-MS which has been optimized. The successful application of thetechnique to large object analysis, residue detection on fingers and remotemonitoring in real time indicates its potential for the analysis of a variety ofsamples, especially large objects and molecular imaging technology. Theability of coupling this technique with most commercial MS with an APIinterface further enhances its widespread use in the field of detectingenvironment pollution, explosive, drug, chemical warfare agent, clinicalmedicine.