Fig. 1.
Schematic view of the on-line and off-line TR-MIMS setup. For on-line experiments PSII membranes were loaded into the home-built MIMS cell and degassed for 20–40 min until stable baselines for all detected gases were reached (Lower Right). This leads to a nearly complete depletion of the samples of Ci. The sample was then illuminated with xenon flashes or by continuous white light from a slide projector. In off-line measurements the PSII membranes were illuminated inside of gas-tight syringes, that is, at well-defined Ci levels (ambient or depleted), and then injected into buffer of identical composition and pH that was thoroughly degassed in the MIMS cell.