ABSTRACT
Phosphorus is a critical element in the biosphere, limiting biological productivity and thus modulating the global carbon cycle and climate (Compton et al. 2000). Much of the phosphorus removed from seawater to sediments is in the form of P included into organic matter (Delaney 1998). Other P chemical forms include phosphorus associated with apatite and calcium carbonate minerals, and with hydrous ferric oxides (Ruttenberg and Berner 1993). Marine sediments are the main reservoir of organic P (on a global scale ca. 5.2 × 1018 mol; Van Cappellen and Ingall 1994) and, as such,
2.1 Introduction ............................................................................................................................ 13 2.2 Field Procedures ..................................................................................................................... 14
2.2.1 Sampling ..................................................................................................................... 14 2.2.2 Sample Storage ........................................................................................................... 14
2.3 Laboratory Procedures: CHN Determination Using Automated CHN Analyzers ................ 15 2.3.1 Equipment and Instruments ........................................................................................ 16 2.3.2 Materials and Solutions .............................................................................................. 16 2.3.3 Procedure .................................................................................................................... 16
2.4 Laboratory Procedures: Spectrophotometric Determination of Phosphorus Pools ............... 17 2.4.1 Equipment and Instruments ........................................................................................ 17 2.4.2 Materials and Chemical Products ............................................................................... 17 2.4.3 Solutions and Preparation of Solutions ....................................................................... 17 2.4.4 Procedure .................................................................................................................... 18 2.4.5 Preparation of Standard P Curves .............................................................................. 18 2.4.6 Calculations ................................................................................................................ 18
2.5 Notes ....................................................................................................................................... 19 References ........................................................................................................................................22
the regeneration of phosphates from this pool is a key step in the regulation of P availability in the overlaying water column.
