Trace iron determination in aminoisophthalic acid using differential-pulse cathodic stripping voltammetry at carbon paste electrodes.
Application of differential-pulse cathodic stripping voltammetry using a carbon paste electrode (consisting of carbon powder and liquid paraffin) have been investigated for trace determination of iron in 5-aminoisophthalic acid (AIPA). Samples were dissolved in 1 M HC1, pH was adjusted to 4-5 after addition of EDTA. Voltammetric measurements were performed after filtration. No sample decomposition (mineralization) was necessary. The method showed a good linearity between current and concentration from 3 x 10(-7) to 5 x 10(-5) mol dm-3 of iron, with a detection limit of 3 x 10(-7) mol dm-3 (resp. 1 ppm in solid AIPA). The results agreed well to those obtained by atomic absorption spectrometry (AAS) using electrothermic atomisation. For AAS measurement, however, microwave digestion of samples was necessary.
Komersová
A
A
Department of Analytical Chemistry, University of Pardubice, Czech Republic.
Bartos
M
M
Kalcher
K
K
Vytras
K
K
D002244:Carbon; D004566:Electrodes; D007501:Iron / Q000032:analysis*; D010795:Phthalic Acids / Q000737:chemistry*; D011048:Polarography / Q000379:methods*
D010795:Phthalic Acids; D002244:Carbon; C102688:5-aminoisophthalic acid; D007501:Iron