Simultaneous determination of nine phytohormones in seaweed and algae extracts by HPLC-PDA

An RP-HPLC-PDA method for the simultaneous analysis of 9 compounds deriving from the phytohormones class was developed and optimized, namely indoleacetic acid (IAA), indolebutyric acid (IBA), phenyleacetic acid (PAA), naphtyleacetic acid (NAA), trans-zeatin (TZ), kinetin (KA), isopentenyladenine (IA), 6-benzylaminopurine (6-BA) and abscisic acid (ABA). Validation of the method was performed on the SFE-CO₂ extract made out of the mixture of Baltic algae. The regression coefficients for plant hormones were in the range from 0.997 to 0.999. The LOD and LOQ were on the levels from 0.05-0.29 and 0.15-0.88mg/L, respectively. Developed method was used for the separation and determination plant hormones in extracts obtained by SFE-CO₂ (supercritical fluid extraction) made out of the mixture of Baltic algae, Cladophora glomerata and Spirulina sp. In the extract of Baltic seaweed 2 of tested compounds were present in the concentration of 154,45±20,63μg/g for TZ and 362,47±13,00μg/g for PAA, whereas in Cladophora glomerata extract contained PAA and IAA in the concentration of 229,30±7,90μg/g and 23,91±0,80μg/g, respectively (all values per g of extract). The differences in the hormones levels may occur due to the different scale of extract preparation (laboratory or industrial) and other factors like the place of algae collection, year of collection or the way of biomass preparation.