基于核磁共振技术的滆湖沉积物有机磷垂直分布特征

Characteristics of Vertical Distribution of Organic Phosphorus by ^(31)P-NMR Technical From Different Sources of Core Sediments in Gehu Lake

选取滆湖湖区3处生态类型不同的代表性沉积物柱状样,采用液相31P核磁共振技术(31P NMR)研究不同形态有机磷的垂直分布,并研究有机质的垂直分布。结果表明,滆湖沉积物有机质含量明显呈由表层至底层逐渐降低的趋势,不同生态类型湖区有机质含量从大到小依次为渔业养殖区、入湖河口区和草型湖区。沉积物可提取有机磷形态含量大小依次为残渣态磷、钙结合态有机磷(HCl-Po)、铁铝结合态有机磷(Na OH-Po)和弱吸附态有机磷(Na HCO3-Po),Na HCO3-Po和Na OH-Po表现出表层富集现象,有机质与有机磷存在显著相关性(P<0. 05),表明绝大部分有机磷来源于有机质组分。31P-NMR分析表明,沉积物中以正磷酸盐为主,磷酸单酯在有机磷中占比最大,磷酸二酯含量随不同生态类型湖区变化显著。

Three typical core sediments located in ditterent ecological sites were selected to study the content and vertical distribution characteristics of organic matters and organic phosphorus in Gehu Lake, characterizing the bioavailability of different organic phosphorus species of these sediments by chemical sequential fractionation and ^31P-NMR technical. The results suggest that the content of organic matters decreased in vertical direction, and represented a distinct tendency in ditterent ecological sites meanwhile： fishery tarming area〉 estuary area〉 float grass area. The organic phosphorus species tollowed the order of Res-P〉 HCI-Po〉 NaOH-Po〉 NaHCOB-PO, and most of potential biological phosphorus NaHCO3-Po and NaOH-Po appeared in upper sediments. With the results of 31 P-NMR, orthophosphate was dominant in biological phosphorus, P-monoester occupied a large proportion of organic phosphorus components, P-diester varied greatly by ditterent ecological lake areas.