Comparison of Three Extraction Methods of Phosphorus in Lacustrine Sediments

There is no defined methods to extract phosphorus from lacustrine sediment. Most methods are applied to the extraction of inorganic phosphorus(IP) from lacustrine sediment. Organic phosphorus (OP) is extracted as a whole package and no fraction information provided is available. Three extraction methods, including standard measurement test (SMT), Ivanoff and Golterman methods are presented on the extraction of IP and OP. The results showed that Ca-bound phosphorus (Ca-P) extracted by SMT method was 16 times of that by Golterman method. Fe/Al-bound phosphorus (Fe/Al-P) extracted by Golterman method was almost 3 times of that by SMT method. The rank order of the OP extracts by different methods was namely Goterlman method >Ivanoff method >SMT method. There was still a great difference on the acid bound OP extracts between Golterman and Ivanoff method, while the other OP fractions were almost equal. The results are helpful for choosing the appropriate extraction method for the research of P fractions from lacustrine sediment.