Fig. 2. RRS spectra of the urea-DMG-C₆₀ system, (a): 0.45 mol L⁻¹ of HCl + 1.65 mmol L⁻¹ of TSC + 3.2 mmol L⁻¹ of DMG + 0.056 mmol L⁻¹ of C₆₀; (b): a + 6.66 nmol L⁻¹ of urea; (c): a + 16.65 nmol L⁻¹ of urea; (d): a + 49.95 nmol L⁻¹ of urea; (e): a + 83.25 nmol L⁻¹ of urea; (f): a + 133.20 nmol L⁻¹ of urea; (g): a + 166.50 nmol L⁻¹ of urea; (h): a + 199.80 nmol L⁻¹ of urea; (i): a + 233.10 nmol L⁻¹ of urea; (j): a + 499.50 nmol L⁻¹ of urea; (k): a + 666.00 nmol L⁻¹ of urea.