Iron is an essential mineral and one of the most abundant in soils, presenting itself in the environment as ferrous and ferric ions. As each oxidation state of iron has a different role in the environment, its speciation in environmental studies is important. The determination of ferrous iron received great attention from soil chemists because of its important role in agriculture, in redox processes, and as an electron acceptor in the catalysis of organic matter. Methodologies with the use of colorimetric reagents to determine ferrous iron are divergent and not very clear. In this study, we compared two colorimetric reagents (1,10-phenanthroline and ferrozine) to determine the total concentration of iron, ferrous and ferric ions in soil, using simple and low-cost methodologies. The determination of ferrous and total iron with 1,10-phenanthroline colorimetric reagent, following published instructions, did not correlate with ferrozine method, presenting an erroneous quantification. After neutralizing the extract of 1,10-phenanthroline with NaOH, both colorimetric methods allowed to quantify with precision and high yield the amount of ferrous and total iron extracted from the soil. The oxidation states of iron have a different contribution and importance to the environment. In this sense, the improvement of a widely used methodology is crucial for the better study of iron speciation in soil.

铁是一种必不可少的矿物质，也是土壤中最丰富的矿物质之一，在环境中以铁离子和铁离子形式存在。由于铁的每种氧化态在环境中的作用都不同，因此在环境研究中其形态非常重要。亚铁的测定因其在农业，氧化还原过程中以及在有机物催化中作为电子受体的重要作用而受到土壤化学家的极大关注。使用比色试剂确定二价铁的方法是多种多样的，而且还不是很清楚。在这项研究中，我们比较了两种比色试剂（1,10-菲咯啉和亚铁嗪），使用简单且低成本的方法确定土壤中铁，亚铁和三价铁离子的总浓度。1，亚铁和总铁的测定 遵循已发布的说明，10-菲咯啉比色试剂与铁佐嗪方法不相关，存在错误的定量。用NaOH中和1,10-菲咯啉提取物后，两种比色法都可以精确，高产量地定量从土壤中提取的亚铁和总铁。铁的氧化态对环境具有不同的贡献和重要性。从这个意义上说，广泛使用的方法的改进对于更好地研究土壤中的铁形态至关重要。两种比色法都可以精确，高产地定量从土壤中提取的亚铁和总铁。铁的氧化态对环境具有不同的贡献和重要性。从这个意义上说，广泛使用的方法的改进对于更好地研究土壤中的铁形态至关重要。两种比色法都可以精确，高产地定量从土壤中提取的亚铁和总铁。铁的氧化态对环境具有不同的贡献和重要性。从这个意义上说，广泛使用的方法的改进对于更好地研究土壤中的铁形态至关重要。