01920naa a2200217 a 450000100080000000500110000800800410001902400270006010000140008724501920010126000090029352011940030265300190149665300260151570000130154170000150155470000170156970000150158670000260160177300750162710472902023-03-13       2005    bl uuuu     u00u1 u    #d7 a10.1021/jf050226r2DOI1 aPARRA, A.  aFlow injection potentiometric system for the simultaneous determination of inositol phosphates and phosphatebphosphorus nutritional evaluation on seeds and grains.h[electronic resource]  c2005  aA simple flow injection potentiometric (FIP) system, which uses a tubular cobalt electrode, has been developed for phosphorus nutritional evaluation of seeds and grains. Inorganic phosphorus, Pi, is determined using a 1 × 10-2 mol?L-1 potassium phthalate buffer solution adjusted at pH 4. A sensitivity of 47 mV/decade and an operating range from 10 to 1000 mg?L-1 (1 × 10-4-1 × 10-2 M) of dihydrogen phosphate are obtained. The inositol phosphates amount, which is referred to the organic phosphorus, Porg, is directly determined from extracts using a 1 × 10-2 mol?L-1 Tris-HCl buffer solution adjusted at pH 8. A sensitivity of 127 mV/decade and an operating range of 10-1000 mg?L-1 (2.5 × 10-4-5 × 10-3 M) of Porg (expressed as inositol hexakisphosphoric acid monocalcium) are achieved. Some samples of seed and grain are analyzed by an ICP-OES and a spectrophotometric method to compare results to the developed flow system; no significant differences at the 95% confidence level are observed using a paired t test. Other samples such as animal nursing feed, soybean meal, and corn are also analyzed with the proposed FIP system, showing a good correlation to the ICP-OES values.  aFlow infection  aPotentiometric system1 aRAMON, M1 aALONSO, J.1 aLEMOS, S. G.1 aVIEIRA, E.1 aNOGUEIRA, A. R. de A.  tJournal of Agricultural and Food Chemistrygv. 53, p. 7644-7648, 2005.