Optimization of performance and minimization of silicate interference in continuous flow phosphate analysis

J. Z. Zhang, Charles J. Fischer, Peter B. Ortner

Research output: Contribution to journalArticle

76 Scopus citations


Specific reaction conditions for automated continuous flow analysis of phosphate are optimized in regard to minimizing coating and silicate interference, while maintaining high sensitivity. Use of Sb in the reagent increases sensitivity and yields absorbances with little temperature dependence. Coating can be minimized by using a final solution at a pH > 0.5. At final pH of 0.78 there is maximum interference from silicate in the sample. We recommend therefore as an optimal reaction condition with minimal silicate interference, the use of Sb, a final solution pH of 1.00, room temperature for the reaction and a [H+]/[Mo] ratio of 70. An equation is provided to correct silicate interference in high precision phosphate determination.

Original languageEnglish (US)
Pages (from-to)293-304
Number of pages12
Issue number2
StatePublished - Jun 1999



  • Coating
  • Continuous flow analysis
  • Phosphate determination
  • Silicate interference

ASJC Scopus subject areas

  • Analytical Chemistry
  • Spectroscopy

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