Abstract Different photosynthetic quinones have been labeled on the carbonyl groups by oxygen exchange with H2 18O and purified by high performance liquid chromatography on normal phase column with non aqueous solvent mixtures. U13C quinones have been extracted from Spirulina maxima, Synechocystis 6803 and E. coli, grown on 13C labeled medium and purified on reversed phase columns. Vitamin K1, plastoquinone PQA45, ubiquinone Q8 have been obtained in mg amounts, while different other quinones (menaquinone MK8, ubiquinones Q2, Q7, Q9, Q11, plastoquinones A) were present only in trace amounts. Several of these quinones have been used in the reconstitution of the photosynthetic reaction centers, in order to assign the quinone bands in the light-induced Fourier transformed infrared difference spectra of the photoreduction of the primary quinone acceptor.