a pure water without buffer; b 5 mM sodium phosphate buffer (pH 7.2) ; c 500 mM mannitol, 10 mM Tricine-BTP (pH 7.4), 1 mM DTT. The data reported in the literature exhibit a variation, depending on which medium or buffer system was used for determining KSV. Usually, at higher buffer concentrations, the reported KSV values are lower, as buffer salts can already lead to partial quenching of the lucigenin fluorescence. Similarly, in presence of 225 mM NaNO3, the KSV values for chloride are ~3.5-fold lower than in pure water (Figure ).