title: Phosphorus composition in sediments from seven different trophic lakes, China: a phosphorus-31 NMR study.
abstract: Information on the chemical composition of sediment phosphorus (P) is fundamental to understanding P dynamics and eutrophication in lake ecosystems. In this study, the surface (10 cm) sediments were collected from seven lakes representing two contrasting ecological areas in China: the middle and lower reaches of Yangtze River region and the Southwestern China Plateau. Phosphorus in these sediments was extracted by NaOH-EDTA and characterized by solution 31P nuclear magnetic resonance spectroscopy. Results show that P in the extracts was dominated by inorganic orthophosphate (76.7-97.4% of the extracted P) and orthophosphate monoesters (1.8-14.3%), with smaller amounts of orthophosphate diesters (0.4-8.9%), pyrophosphate (0.1-0.7%), and phosphonates (0.1-0.2%). The relative abundance of orthophosphate was higher in hypertrophic and shallow lake sediments than in eutrophic and mesotrophic and deep lake sediments, whereas the relative abundance of orthophosphate monoesters was the opposite. These observations suggested that the relative abundance of the two types of P forms in sediments might be related to the degree of lake eutrophication.
authors.affiliation: State Key Lab. of Environ. Geochemistry, Inst. of Geochemistry, Chinese Academy of Sciences, Guiyang 550002, China.
authors.forename: Runyu
authors.initials: R
authors.lastname: Zhang
authors.forename: Fengchang
authors.initials: F
authors.lastname: Wu
authors.forename: Zhongqi
authors.initials: Z
authors.lastname: He
authors.forename: Jian
authors.initials: J
authors.lastname: Zheng
authors.forename: Baoan
authors.initials: B
authors.lastname: Song
authors.forename: Linhong
authors.initials: L
authors.lastname: Jin
mesh_terms: D002681:China; D005068:Eutrophication; D005618:Fresh Water / Q000032:analysis*; D019015:Geologic Sediments / Q000032:analysis*; D009682:Magnetic Resonance Spectroscopy; D010710:Phosphates / Q000032:analysis; D010758:Phosphorus / Q000032:analysis*; D017553:Phosphorus Compounds / Q000032:analysis*; D010759:Phosphorus Isotopes / Q000032:analysis
chemical_list: D010710:Phosphates; D017553:Phosphorus Compounds; D010759:Phosphorus Isotopes; D010758:Phosphorus