FIG. 1.

Comparison of H₂S measured in buffer, human plasma, and human whole blood with the amperometric H₂S sensor and the monobrombimane (MBB) method. Na₂S (final concentration 10 μM) was added to HEPES buffer (50 mM HEPES, 155 mM NaCl, 3 mM glutathione, 1 nM diethylenetriaminepentaacetic acid, pH 8.0), human plasma, or human whole blood. Both methods produce similar results in HEPES buffer and plasma. However, in whole blood there was only a transient spike in sulfide when measured with the amperometric sensor, whereas more than three times as much sulfide was measured with the monobromobimane (MBB) method and sulfide concentration remained elevated for at least 30 minutes. Redrawn from Wintner et al. (77), with permission.