Determination of phosphate compounds in meat products by 31-phosphorus nuclear magnetic resonance spectroscopy with methylenediphosphonic acid after alkaline extraction.

Modification of the extraction procedure and application of the (31)P NMR method for the determination of polyphosphates in meat products were studied. In the elaborated procedure threefold water extraction at alkaline pH (borate buffer and 0.1 M EDTA) was applied. Furthermore, the new external standard for (31)P NMR determination of phosphates was proposed. Obtained recoveries were between 95 and 99% and variation coefficients (CV) was < or = 5%, indicating an increase in accuracy and the precision of the proposed procedure in relation to the spectrophotometric method. The described procedure of sample preparation with (31)P NMR method was applied for the determination of polyphosphate additives in meat products. The satisfactory precision (CV=0.39-3.40%) shows the benefit of the NMR method in the routine analysis of the phosphate ions in meat products.