Biomolecular Analysis and Biological Tissue Diagnostics by Electrospray Ionization with a Metal Wire Inserted Gel-Loading Tip

A metal wire-inserted disposable gel-loading tip was examined as an electrospray emitter. Its performance was similar to that of conventional electrospray ionization (ESI) with a relatively low flow rate (∼100 nL/min) and without the need for solvent pumps. It was also used as an emitter for solid probe-assisted ESI (SPA-ESI) (e.g., biofluid was sampled from the biological tissue by a needle and was inserted into the solvent-preloaded gel-loading tip). Selective detection of lipids and proteins, such α and β chains of hemoglobin could be accomplished by choosing appropriate solvents. A suitable protocol for cancer diagnosis was established by this method. A good figure of merit of this method is its applicability to biological tissue diagnostics with high cost efficiency and on a disposable basis

Development of Sheath-Flow Probe Electrospray Ionization Mass Spectrometry and Its Application to Real Time Pesticide Analysis

For the real time and direct analysis of chemical constituents from living beings and dry sample, sheath-flow probe electrospray ionization mass spectrometry (SF-PESI-MS) has been newly developed. The components from dry or semidry biological tissues can be extracted using the solvent and picked up by the needle for electrospray. This technique was applied to real-time pesticide analysis of living plants. The results have been validated with that of a well-known system, liquid extraction surface analysis mass spectrometry (LESA-MS). It is demonstrated that SF-PESI-MS can produce reasonable ionization efficiency, which is confirmed by LESA-MS