Flow injection spectrophotometric determination of ultra trace amounts of oxalic acid.
A new simple, sensitive and rapid catalytic-spectrophotometric method for the determination of oxalic acid has been described based on its catalytic effect on the redox reaction between dichromate and Brilliant cresyl blue in acidic media by means of a flow injection analysis method. The color change of Brilliant cresyl blue due to its oxidation was monitored spectrophotometrically at 625 nm. The calibration graph was linear in the range of 0.020-4.70 microg/mL oxalic acid with a limit of detection 0.005 microg/mL of oxalic acid. The relative standard deviation for ten replicate measurements of 0.020 microg/mL and 0.900 microg/mL was 2.2% and 1.7%, respectively. No serious interference was identified. Oxalic acid was determined in wastewater and in spinach by the proposed method with satisfactory results.
College of Chemistry, Isfahan University of Technology, Iran.
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Ensafi
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Kazemzadeh
D006863:Hydrogen-Ion Concentration; D007202:Indicators and Reagents; D019815:Oxalic Acid / Q000032:analysis*; D010084:Oxidation-Reduction; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013053:Spectrophotometry / Q000379:methods
D007202:Indicators and Reagents; D019815:Oxalic Acid