The problem of arsenic interference in the analysis of soils for cadmium by inductively coupled plasma-optical emission spectrometry.

Cadmium determination in soils that contain arsenic may be subject to interference. When this problem is not appreciated spurious results may be accepted as correct. Spectrometric methods for the quantitative determination of cadmium in the presence of arsenic were compared. Data are given for each method to demonstrate the problem of arsenic interference. Cadmium determination by Flame Atomic Absorption Spectrometry was free from arsenic interference. Cadmium determination by Inductively Coupled Plasma Spectrometry and Graphite Furnace Flame Atomic Absorption Spectrometry were subject to interference at arsenic concentrations greater than 50 microg l-1 and 10 mg l-1, respectively. A strategy for cadmium determination in arsenic contaminated soils is suggested.