[Refining sample preparation procedures for solution 3P-NMR analysis of organic P in sediment].

Solution phosphorus-31 nuclear magnetic resonance spectroscopy (31P-NMR) is a novel technology in characterization of organic phosphorus (P) composition in sediments. This study was aim to refine sample preparation procedures for 31P-NMR, including determination of sample pretreatment, extraction time, sample to extractant ratio and concentration method. The results showed that recovery of P with air dried sample treatment was higher than that for the fresh samples. Most of the P was extracted within the first 8 hours, and the time could extend to 12 to 16 hours in order to improve the recovery of P. Using the extraction ratio [m(sediment): V(extractant)] of 1:8 received more spectral signals compared to 1:20 when both the extracts were concentrated at the same time. No evident loss of P was found when the extract was concentrated at 28 degrees C followed by centrifugation under low temperature.