Characterization of phosphorus in algae from a eutrophic lake by solution ³¹ P nuclear magnetic resonance spectroscopy

The identification and quantification of phosphorus (P) compounds derived from algal biomass are crucial for a better understanding of algal P dynamics in lake ecosystems. Quantity and species of P in algae collected from Chao Lake (a typical ultra-eutrophic lake) in China were analyzed by chemical analysis and ³¹ P NMR. Total P (TP) in algae biomass ranged from 2671 to 5385 mg kg ⁻¹ of dry matter. Proportion of organic P (P _o ) accounted for 78.3 ± 2.6% in algae biomass collected from the western part of Chao Lake, which was higher than that (64.7 ± 1.4%) in the eastern part of the lake. Eight P species including inorganic P species (orthophosphate and pyrophosphate) and P _o species (five monoesters P and diesters P) were identified in NaOH–EDTA extracts of algal samples. Monoesters P accounted for 48.4% in extracted TP, which was the main component of P _o . β-glycerophosphates were the largest component of monoesters P, which accounted for 22.6% in extracted TP. This study improved knowledge on the mechanism of the cycling of endogenous P in the aquatic system and would be helpful in developing a strategy for control of repeated algae blooms in eutrophic Chao Lake.