Ottoman palace weavings between different periods: material characterization, comparison and suggestions for conservation

Heritage Science

Table 2 The retention times and the UV–Vis spectra (absorbance maxima) at HPLC–PDA of reference dyestuff standards

Trial no.	Reference dyestuffs	Retention time (min)	Absorbance maxima (nm)
1	Alizarin	28.359	249, 279, 331sh, 429
2	Apigenin	25.350	219, 267, 293sh, 337
3	Carminic acid	16.715	233, 275, 310, 351sh, 469sh, 495, 531sh
4	Ellagic acid	16.476	253, 305sh, 368
5	Flavokermesic acid	26.370	219, 285, 343sh, 431
6	İndigotin	28.396	243, 285, 331, 609
7	İndirubin	30.684	241, 289, 362, 541
8	Luteolin	22.442	255, 265, 291sh, 349
9	Purpurin	28.465	229, 255, 295, 481, 513sh
10	Sulphuretin	23.059	257, 269, 395
11	Xhantopurpurin	29.851	243, 281, 337sh, 411