Use of sequential extraction with UV/Vis spectrophotometer to assess phosphorus species in surface sediments (NE Mediterranean Sea)

The speciation of total phosphorus in different forms is necessary to understand the phosphate exchange mechanisms In sediments, its potential removal from the water column, and the availability of phosphorus for primary producers. This paper presents the phosphorus (P) distribution (total phosphorus, organic phosphorus, and forms of inorganic phosphorus; loosely adsorbed phosphorus and phosphorus bound to aluminium, phosphorus bound to calcium, and phosphorus bound to iron, as well as total inorganic phosphorus) in surface sediments collected from two coasts (each under different anthropogenic pressures) in the eastern Mediterranean Sea in April 2007. The sampling stations are located at on the south-eastern Mediterranean coast of Turkey, adjacent to the Cillcian Basin. The most abundant phosphorus in studied surface sediments was found as calcium-bound phosphorus. Relative abundances of the remaining phosphorus forms follow the order: P-Al > loosely bound-P > P-Fe. The concentration of total phosphorus in the surface sediments taken from Tasucu was found to be higher than the sediments from Erdemli. Accuracy of the method was checked by using NCS DC 73316 certified reference material and the results found were found to be in good agreement with the certified value. Maximum values of total P in Erdemli and Tasucu were 220.35 and 321.42 µg g-1, respectively