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.
Department of Analytical Chemistry, University of Pardubice, Czech Republic.
A
A
Komersová
M
M
Bartos
K
K
Kalcher
K
K
Vytras
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