Table 2.

Longitudinal relaxation times obtained for HGAm, GAm, and Dopa melanin samples, recorded at room temperature. A biexponential decay was used to interpret the saturation recovery results: $\mathrm{y}={\mathrm{A}}_{\mathrm{f}}\exp \left(-\frac{\mathrm{t}}{{\mathrm{T}}_{1\mathrm{f}}}\right)+{ \mathrm{A}}_{\mathrm{s}}\exp \left(-\frac{\mathrm{t}}{{\mathrm{T}}_{1\mathrm{s}}}\right)+\mathrm{c}$. An experimental error of ±3 µs can be considered in the data reported for the HGAm and Dopa melanin data, while an experimental error of ±5 µs has been considered for GAm.

	T1s (μs)	T1f (μs)	Af/As
HGAm	254	59	1.51
GAm	170	44	1.13
Dopa melanin	216	61	1.50