Concentrations of lipid phosphorus and its abundance in dissolved and particulate organic phosphorus in coastal seawater

Analytical procedures to determine lipid phosphorus (lipid P) in seawater w ere developed and tested using a combination of solvent and solid-phase ext raction. Lipid P was extracted from particulate and dissolved matter in sea water with a solvent mixture of chloroform and methanol. Silica gel solid-p hase extraction (SPE) was evaluated using phospholipid and hydrophilic comp ounds. SPE exhibited high recoveries of phospholipids from the solvent mixt ure and was also effective in removing contamination from hydrophilic compo unds. The method was applied to coastal seawater samples to investigate the quantitative significance of lipid P in marine organic P. In samples colle cted from Tokyo Bay, Japan, and Corpus Christi Bay, USA, concentrations of particulate lipid P ranged from 31 to 300 nM, which corresponded to 3-14% o f the total particulate P. Concentrations of dissolved lipid P were low ran ging from 0.7 to 6 nM, which were less than 1% of the total dissolved organ ic P concentrations. Thus, lipid P is a significant component of particulat e P, but a rather minor component of dissolved organic P. (C) 2001 Elsevier Science B.V. All rights reserved.