Automatic spectrophotometric determination of copper in plant material, soil, and fertilizer mixtures by a kinetic method

Knowledge of metal concentration in soils, plant material, and fertilizers is important both for plant nutrition as for environment contamination studies. In this paper, an automated spectrophotometric method using Flow Injection Analysis (FIA) for copper (Cu) determination was studied. That method was based on the catalytic effect of Cu2+ ions in the color fading of the red-purplish complex formed when iron (Fe3+) and thiosulfate (S2O32-) ions react. The principal feature of the studied method is its high selectivity, which allowed the Cu determination in a complex matrix as nitrogen (N):phosphorus (P):potassium (K) fertilizer mixtures without effect of interference. Soil and plant tissue samples were also analyzed with good precision and accuracy when compared with atomic absorption spectrophotometry.30419841641164