| On behalf of a new generation of ion source,direct analysis in real time(DART)is used for rapid ionization of small molecules under ambient conditions.DART can be combined with a mass spectrometer to detect a variety of food samples and requires simple preparation or no sample preparation.The production and processing process are critical links in food supply chain.It needs to develop a fast,simple and accurate method to ensure the quality and safety of food in every link.In this study,DART-MS/MS was used to establish real-time direct detection of potential chemical contaminants in the production or processing of wine,salt and milk.1.Without pretreatment and chromatographic separation,combined with triple quadrupole mass spectrometry,a direct analysis in real time method for detection of 31 pesticides in wine was developed.By optimizing parameters of DART and mass spectrometry,the detection speed and accuracy of method were improved.The analytes had good linearity in the range of 10～100 ng/mL.The LOQs were in the range of 25-500 ng/mL.The average recoveries were in the range of 81%127%.2.For the first time,DART was combined with high-resolution mass spectrometry to develop a method for the analysis of volatile organic acids in"smelly salt".The extraction solvent and its volume were optimized,and the mass spectrometry conditions were also optimized.The results showed that good linearity was obtained in their corresponding concentration.The LOQs ranged from 0.9 to 3.1 μg/g.The average recoveries were in the range of 81%～114%.3.A real-time analysis for furosine,a byproduct of milk processing,has been established,which was direct,rapid and easy to operate.Variables including ion source gas temperature,injection rate,vacuum pump suction and mass spectrometry conditions were investigated.Furosine revealed good linearity in its corresponding concentration range.The LOQ was 5 μg/g.The average spiked recoveries were in the range of 63%～114%. |
