Active Paper Spray Mass Spectrometry For Biofluid Analysis

MS is a fast developed analytical method with wide application. It has been applied to life science, environment investigation, pharmaceutical studies, and food science.Modern MS analysis is characterized with high sensitivity, high specificity and high throughput. Since new ionization sources play an essential role in MS development, many investigations have been focused on the development of novel ionization sources. Moreover, many of the ionization sources are designed for complex matrix, such as urine, blood and so on. However, for the necessary of complex pretreatment steps before sample analysis, it has limited the application of conventional ionization sources, such as EI, CI, FAB, MALDI, and ESI. On the other hand, with the development of GC-MS, LC-MS, LC-UV and CE, they have greatly promoted sample analysis in complex matrix. Among these methods, LC-MS is the mostly commonly used one. However, these methods accompany with the disadvantage of time-consuming and complication. Therefore, it is in an urgent need to develop simple, efficient and low-cost MS ionization source for biofluid sample analysis.Ambient ionization source is a kind of novel source developed in recent years, which has the advantages of in-situ, real-time, non-destruction, high-through and low sample-consumption, avoiding complex pretreatment procedures. Since the invitation of DESI by cook’s group in2004, ambient ionization sources have attracted people’s increasing attention. Up to date, dozens of such ionization sources have been developed and was applied to complex sample analysis.Paper Spray (PS), one kind of ambient ionization source was first reported in2010. When solid or liquid samples were placed on the paper substrate, the sample molecules are extracted by solvent and ionized under high voltage conditions. With the transfer of ions from liquid to gas phase, they are detected by mass spectrometer. Since PS has the advantages of rapidity, low-cost, and easy-operation, it is intensively applied to sample analysis in biofluids, such as blood urine, blood and so on.In this work, we have made a modification to conventional ps. With combination of chemical reaction with PS, we have achieved the goal of in-situ detection of biofluid samples. We named this method as "reactive PS". The main contexts include five aspects:1) development of reactive PS and explore the mechanism of it.2) Comparison of normal PS and reactive PS3) optimization of the experiment parameters in reactive PS4) qualitative and quantitation analysis of quinones with reactive PS5) application of reactive PS to complex matrix.We have developed novel ambient ionization source-reactive PS. With in-situ reaction of quinones and cysteamine as an example, we have illustrated that PS could be applied to qualitative and quantitation analysis of quinones. Besides, this method could also apply to quinones detection of biofluid samples, such as raw urine, whole blood and serum. We believe that reactive PS could be widely used to environmental science, metabonomics, and clinic field in the future as well as biofuild sample analysis.