Journal of the Serbian Chemical Society (Jan 2003)

Spectrophotometric determination of phosphorus in coal and coal ash using bismuth-phosphomobybdate complex

  • Mihajlović Ranđel P.,
  • Ignjatović Nataša R.,
  • Todorović Marija R.,
  • Holclajtner-Antunović Ivanka D.,
  • Kaljević Vesna M.

DOI
https://doi.org/10.2298/JSC0301065M
Journal volume & issue
Vol. 68, no. 1
pp. 65 – 73

Abstract

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A modified spectrophotometric method using the bismuth phosphomolybdate complex for the determination of phosphorus in coal and coal ash is suggested. Bismuth together with phosphate and molybdate forms a very stable complex in acid medium which turns blue ("molibdenum blue") by reduction with ascorbic acid. The apparent molar absorptivity of PBiMo is 1.66x104 dm3 mol-1cm-1 at 720 nm and 2.10x104 dm3 mol-1cm-1 at 670 nm isobutyl methyl ketone (MIBK). Interference caused by the ions present are within the tolerance limits (±2 %). Beer’s law is obeyed in the for concentration range to 0.6 μg/mL (aqueous solution) and to 1.2 μg/mL P (MIBK). The sensitivity of the proposed method is 0.0078 μg/mL (aqueous solution) and 0.0066 μg/mL (MIBK).

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