Determination of phosphorus by phosphorus molybdenum blue spectrophotometry by bismuth antimony sensitization

ABSTRACT. The determination of phosphorus in rain water is of great significance. In this paper the optimum conditions of phosphorus molybdenum blue spectrophotometric method for the determination of phosphorus content were obtained. At the maximum absorption wavelength 690 nm, the apparent molar absorptivity is ε690 nm = 1.44 × 104 L·mol-1·cm-1. Beer’s law is followed over the range of 0.02-1.8 μg·mL-1 for phosphorus(V) content. Bismuth(III) and antimony(III) as the sensitizer has a sensitization effect on the phosphomolybdenum blue photometry. The addition of both simultaneously increases the sensitivity by 71.3%. The present method has been used for the determination of phosphorus in water samples. The recovery of method is between 99.20 - 100.1% and the relative standard deviation is between 1.31-1.33% for eleven determination. The results determined by the present method were in agreement with those of atomic absorption spectrometry. This method can avoid the harm of organic reagent to human body and to environmental pollution without organic solvent extraction. This method does not need heating with room temperature color development. Compared with other methods, it has the advantages that the operation is simple, fast and the sensitivity is high. Bull. Chem. Soc. Ethiop. 2023, 37(6), 1307-1313. DOI: https://dx.doi.org/10.4314/bcse.v37i6.1