基于液相31P核磁共振(NMR)技术的巢湖沉积物中有机磷形态研究

利用改进的沉积物有机磷提取方法和液相31P核磁共振(NMR)分析方法,研究了巢湖表层沉积物有机磷形态.结果表明:西部湖区表层沉积物总磷含量高于东部湖区,其平均含量分别为(1089.82±108.14) mg·kg-1和(497.80±51.59) mg·kg-1;东部湖区沉积物中有机磷百分含量(31.88％±2.41％)高于西部湖区(20.86％±1.65％);表层沉积物主要磷份组成包括膦酸盐(Phon-P)、正磷酸盐(Ortho-P)、磷酸单酯(Mono-P)、磷脂(Lipid-P)、DNA(DNA-P)、焦磷酸盐(Pyro-P);磷酸单酯为有机磷的主要组分,平均含量占总磷的22.12％±5.32％;磷酸单酯和DNA百分含量东部湖区大于西部湖区,磷酸单酯百分含量分别为25.99％±2.29％和16.30％±1.06％,DNA百分含量分别为5.61％±0.24％和3.85％±1.01％.31P核磁共振技术可以有效的应用于巢湖等富营养化湖泊沉积物磷形态分析;巢湖表层沉积物以无机磷为主,有机磷种类丰富,以磷酸单酯为主.

Detection of phosphorus species in the sediments of Chaohu Lake by 31P nuclear magnetic resonance spectroscopy(31P-NMR)

Phosphorus (P) species in the sediments of Chaohu Lake were detected by ³¹P nuclear magnetic resonance spectroscopy (³¹P-NMR). Total P (TP) contents in the sediments of western lake ((1089.82±108.14) mg·kg^-1) were higher than that in eastern lake ((497.80±51.59) mg·kg^-1). The proportion of organic phosphorus (P_o) in the sediments of eastern lake 31.88%±2.41% was higher than those of western lake 20.86%±1.65%. Six P species, including two inorganic P species (orthophosphate and pyrophosphate) and four P_o species (phosphonates, orthophosphate monoesters, phospholipids and DNA) were detected in the NaOH-EDTA extracts by³¹P-NMR. The main component of P_o was phosphate monoesters, which accounted for 22.12%±5.32% in total P_o. The percentages of orthophosphate monoesters and DNA in the sediments of eastern lake (25.99%±2.29% and 16.30%±1.06%, respectively) were higher than those of western lake (5.61%±0.24% and 3.85%±1.01%, respectively). We demonstrated that ³¹P-NMR was an ideal technique for analyzing P_o species in the sediments of eutrophic lakes.