B

Fig. 1. (A) Diagram of electrochemical NMR cell: A, the counter electrode, encased in a 14/20 male joint. B, Upper electrolyte reservoir; C, Sample chamber for Pt black; D, working electrode lead connected to Pt gauze in sample chamber; E, vacuum/waste Luer connection; F, Reference electrode Luer connection. (B) The assembled electrochemical NMR probehead.

This cell has been designed to allow for sample preparation and signal acquisition to occur without interruption of circuit continuity, since it is now possible to prepare samples within the probe, then immediately begin NMR measurements. The large electrolyte reservoir, which houses the counter and reference electrodes, provides ample electrolyte for complex and lengthy measurements to be made, without solvent evaporation. The location of the PC platinum black powder is within the long sample region of the electrochemical NMR cell (Fig. 1(A)). The sample cell is wrapped with a copper wire (NMR coil) which serves for both excitation and signal acquisition (Fig. 1(B)). The electrochemical NMR cell incorporates the ability to exchange the electrolyte without removing the probe containing the electrochemical NMR cell from the magnet. When directly connected to a potentiostat, use of the electrochemical NMR cell requires electronic filtering of the electrochemical leads entering the probehead, in order to eliminate environmental radio-frequency (RF) pickup which would otherwise be introduced (see Section 2.3).

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