Author/Authors :
Hemmati Yadkoori, Amin Department of Chemistry - Yasouj University, Under Hill, Yasouj, Iran , Khajehsharifi, Habibollah Department of Chemistry - Yasouj University, Under Hill, Yasouj, Iran , Shokrollahi, Ardeshir Department of Chemistry - Yasouj University, Under Hill, Yasouj, Iran , Bordbar, Mohammad Mahdi Department of Chemistry - Yasouj University, Under Hill, Yasouj, Iran
Abstract :
Herein, a simple, sensitive, and rapid chemosensor is reported for the colorimetric detection and determination of oxalate ions. This
system produces a visible color change from purple to yellow based on the indicator displacement assay (IDA) approach. The reaction of
Eriochrome Cyanine R (ECR) as an indicator and vanadyl ions (VO2+) at pH 6.00 acts as a chemosensor for oxalate ions (Ox). Adding
oxalate ions to the designed chemosensor causes the replacement of the vanadyl ions with the oxalate ions to binding the indicator. Due to
this displacement, the solution color returns to yellow with about 80 nm blue shifts (530 to 450 nm). Also, the formation constants of ECRVO2+
and VO2+-Ox complexes were determined to be 6.13 and 13.94, respectively using spectrophotometric titration. Under the optimized
experimental conditions, the chemosensor exhibited a dynamic linear range for oxalate ions from 8.30 × 10-7 -1.13 ×10-4 M, with a detection
limit (S/N = 3) of 5.40 × 10-7 M. The relative standard deviation (RSD) value was evaluated to be 0.52% for five determinations of oxalate
(6.02 μM). The designed sensor was applied successfully for the determination of oxalate ions in human urine samples with the recoveries
of 96.36 to 105.73% showing satisfactory results.
Keywords :
Eriochrome cyanine R , Vanadyl , Oxalate , Chemosensing ensemble
