Establishment And Application Of Direct Analysis In Real Time Device For Ionization In Mass Spectrum

Compared with traditional ionization methods,open-air in situ ambient ionization methods were more convenient and easier application in broader samples. Among them,direct analysis in real time (DART) shows mature in many applications, and paper spray ionization looks more simple and effective. They have attracted great attention. In the thesis, we constructed a flexible device of the DART for mass spectrum analysis, presented a new kind of glass slide spray ionization according to the principle of paper spray, and studied the peel spray ionization to analyse pesticide residues on the surface of peel. So, the thesis includes three parts:flexible device of the DART for mass spectrum analysis, glass slide spray ionization mass spectrum, and peel spray ionization for detection of pesticide residues.① Design and build a flexible and simple DART device for mass spectrometer injection. It contains inert gas, ionizer, heater and temperature-controller, pipeline etc.Excluding the grid electrode and then reducing the structure units, the device can be easy to build up in low cost and flexible to connect with a variety of mass spectrometers. Combined with mass spectrometer, the device was used to analyze qualitatively benzene alcohol, linoleic acid, dichlorvos emulsion, mosquito coils, citrus peel, and sample (propranolol hydrochloride) on thin-layer plate.The results were accurate and showed the device stable and reliable.② A new kind of glass slide spray ionization is presented according to the principle of paper spray. Some experimental conditions were investigated for their influence on MS peak intensity including the angle of slide tip, the distance between slide tip and injection port of mass spectrometer, internal voltage of mass spectrometer, and sample solution’s acidity. The results suggested 60°as the angle of glass slide tip appeared spray,2.0±0.2mm as distance, The sample solution acidity had little difference to the MS peak intensity,4500V as internal voltage, to obtain the intensity of MS peak as more than 108. The method has been applied to analyse some real samples like propranolol hydrochloride,hemin, quinine, chlorhexidine acetate, compound sodium sulfamethoxazole eye drops with the analytical results agree with their theoretical value better at the experimental condition of 4M resolution.③ Qualitative analysis of pesticide residues using peel spray ionization directly. Qualitative analysis of different kind of pesticide residues (deltamethrin,dichlorvos, acetamiprid, dursban, pyridaben)in different peel including banana, apple,orange was investigated.The result shows the peel spray ionization can be used for analysis of pesticide residues on the surface of peel.