*2.4. HPLC–DAD Experimental Details*

Samples were treated with hot dimethyl sulfoxide (DMSO) to extract and solubilize the colorants [30]. The HPLC-DAD system (Thermoquest, Manchester, UK) consisted of a 4000 quaternary HPLC pump, a SCM 3000 vacuum degasser, an AS3000 auto sampler with column oven, a Rheodyne 7725i Injector with 20 μL sample loop, and a Diode Array Detector UV 6000LP. The HPLC was operated using (A) water + 0.1% (*v*/*v*) trifluoroacetic acid and (B) acetonitrile + 0.1% (*v*/*v*) trifluoroacetic acid [30]. Separation was achieved with an Altima C18 (Alltech Associates Inc., Chicago, IL, USA) column (5 μm particle size, 250 mm × 3.0 mm) at a stable temperature of 35 ◦C using the following gradient elution [30]: 0–0.5 min: 50% B isocratic; 0.5–12 min: linear gradient to 60% B; 12–12.5 min 60% B isocratic; 12.5–14 min linear gradient to 70% B; 14–17 min linear gradient to 85% B; 17–18 min 85% B isocratic; and 18–21 min linear gradient to 100% B. The amounts of the analyzed samples were in the order of 0.5 mg.
