Serious Interferences in the Determination of Trace Metals in Soils by Flame and Flameless Atomic Absorption Spectrometry

Abstract

Negative interfering effects on the carbon rod atomizer (CRA) absorbances of Mn, Fe, and Ni were found to occur in the presence of the chlorides of the major cations (Ca, Mg, Na) in the soil solution. These interferences were corrected either by precipitation of the chlorides with silver nitrate or by incorporating a relatively high level of sulfuric or nitric acid into the sample volume. Magnesium ion, irrespective of the associated anion, was found to lower the Cd signal on the CRA. High concentrations of MgSO4 caused lowering of the Mn signal when using air‐acetylene flame. This lowering effect of MgSO4 was avoided upon using N2O‐acetylene flame. No interferences were noticed for Mn and Zn when using the constant temperature furnace developed at Montana State Univ.

Comparative interference study for atomic absorption lead determinations using a constant temperature vs. a pulsed-type atomizer

“…Previous reports (8,18) show that little or no interference is observed in the analysis of manganese and several other elements when utilizing the constant temperature furnace (CTF). Data showing reduction of background and minimal interferences for direct analysis of biological samples have also appeared (19).…”

Background reduction during direct atomization of solid biological samples in atomic absorption spectrometry

“…Interferences. The ability of the constant temperature furnace to eliminate the signal-suppressing effect of halide interferents has recently been documented (28). Churella and Copeland (29) note that long furnace tubes would eliminate interferences due to occlusion.…”