Analysis of phosphore using ammonium molybdate with thiourea and hydrazine sulphate as reductors by UV-VIS spectrophotometry method.

Analysis of phosphore using UV-Vis Spectrophotometric has been studied. The aims of this research were to get the optimum conditions for analysis phosphore, to obtain information on the best reductor, and to apply this method for analysis phosphore in peanut that reach method validation parameters. This research begins with determination of optimum conditions of phosphorus analysis by forming a yellow complex compound. This compound was unstable so it needs to be reduced using thiourea and hydrazine sulphate to produce a stable blue complex. Furthermore, the phosphorus analysis method was validated based on the method validation parameters. Molybdenum blue reaction produced a heterophosphomolybdate complex compound which has a maximum wavelenght 689 nm. The method validation results of phosphomolybdate have linierity (R2) were 0.9984 and 0.9961 for hydrazin sulphate and thiourea as reductors. The molar absorptivity were 7.92 x 104 L mol−1 cm−1 and 2.93 x 105 L mol−1 cm−1 for hydrazin sulphate and thiourea. It had limit detection of 5.26 x 10−4 mg L−1 for hydrazine sulphate and 5.62 x 10−3 mg L−1 for thiourea. The %RSD values in each sample ranged from 1.08 to 1.40%. %recovery obtained in each sample ranged from 90% - 117%. The phosphates contained in the peanut samples did not pass the food quality standard according to the Indonesian Nutritionist Association (PERSAGI). [ABSTRACT FROM AUTHOR]