Yield:-

Reaction Conditions:

with formic acid in water;Electrochemical reaction;

Steps:

Online EC/DESI-MS Apparatus

General procedure: A home-built apparatus for coupling a thin-layer electrochemical flow cell with either a Waters Xevo QTof mass spectrometer (Milford, MA, USA) or a Thermo Scientific LCQ DECA mass spectrometer (San Jose, CA, USA) by liquid DESI wasused (apparatus shown in Scheme 1S, Supporting Information) and described previously in detail [20]. The Reactor Cell (Antec BV, Zoeterwoude, The Netherlands) equipped with agold disc working electrode (i.d. 8 mm) was used for nitrosothiol reduction and saccharide oxidation. A HyREF electrode was used as the reference electrode, and carbonloaded PTFE was used as a counter electrode. The μ-PrepCell (Antec BV, Zoeterwoude, The Netherlands) equipped with a glassy carbon working electrode (30 × 12 mm2) was employed for carbamazepine oxidation. A HyREF electrode was used as the reference electrode and titanium was used as the auxiliary electrode. The electrochemically oxidized or reduced products flowed out of the cell via a short piece of fused silica connection capillary (i.d. 0.1 mm, length 4.0 cm) and underwent interactions with the charged microdroplets from the DESI spray for ionization. The capillary outlet was placed about 1 mm downstream from the DESI spray probe tip and kept in line with the DESI sprayer tip and the mass spectrometer's inlet. For the positive iondetection mode, the spray solvent for DESI was methanol/water (1:1 by volume) containing 1% acetic acid, and a high voltage of 5 kV was applied to the spray probe. For the negative ion mode used for saccharide oxidation monitoring, the spray solvent for DESI was methanol/water (1:1 by volume) containing 1% ammonia, and a high voltage of -5 kV was applied to the spray probe. Injection flow rates for both the DESI spray solvent and the sample solution for electrolysis were 10 μL/min.

References:

Lu, Mei;Liu, Yong;Helmy, Roy;Martin, Gary E.;Dewald, Howard D.;Chen, Hao [Journal of the American Society for Mass Spectrometry,2015,vol. 26,# 10,p. 1676 - 1685]