||To provide a new type of mass spectrometer for in situ chemical detection/screening is a trend of development of mass spectrometry. In this study three mobile mass spectrometers (MMS) have been developed by using top-down strategy. Commercial MS and instruments such as power supply and gas supply etc. have been integrated on electro-dynamic vehicles with vibration dampening system. MMS has high performance as commercial MS comparing with portable mass spectrometers which have been developed by using bottom-up strategy.|
A mobile ambient mass spectrometer (MAMS) is combined a new type of ionization source which so-call thermal desorption-electrospray ionization (TD-ESI) with the MMS. MAMS provides rapidly and in situ chemical analysis such as food safety screening and narcotic detection.
In this thesis, DEHP tainted in food, melamine in milk products and pesticide residues on/in agricultural product have been detected to simulate reality. The results showed that their LODs are 500 ng/mL, 2.5 μg/mL and 5.0μg/mL respected to DEHP in aqua, juice and milk. And, the LOD of melamine in milk powder has been estimated about 1mg/g. Then, LOD of thiabendazole on fruits surface was 500 ng/mL and the distribution by permeating into fruit has been detected. Finally, we found that there were about 80% fruits and vegetables with agricultural residues which bought from the local markets.
Furthermore, methyl amphetamine, MDMA, ketamine and heroin have been detected to stimulate narcotic detection. The LODs of MA and MDMA standard solutions were 500 ng/mL. The LODs of ketamine and heroin powders were 1μg/g. We propose that MAMS will surely increase MS ability for in situ detection.