Coca cola® is it! the ubiquitous extractant for micronutrients in soil

Abstract

Abstract Coca Cola® has been found to be an excellent extractant for micronutrients in soils, particular for manganese (Mn). The main ingredients of Coca Cola®, phosphoric acid, reducing sugar and carbon dioxide are well proven in common extraction recipes. The overall extraction force of Coca Cola® was similar to that of commonly used phosphoric acid methods. Compared to DTP A, Coca Cola® extracted only 27% of iron (Fe), 38 % of copper (Cu), and 86% of zinc (Zn), but 165% of Mn. Correlation coefficients for the relationship between Coca Cola®‐extractable Fe, Zn, and Cu in soils and element concentrations in plants were the same as by means of the DTPA method. For Mn 49% of the variability in Mn concentrations observed in field grown winter wheat plants could be explained by Coca Cola®‐extractable soil Mn, but only 39% when employing DTPA. The critical value for available Mn and Zn on the investigated inceptisols was 17.8 mg/kg Mn and 1.3 mg/kg Zn for Coca Cola® and 9.4 mg/kg Mn and 1.8 mg/kg Zn for DTPA. Tentative critical values for Fe and Cu are 19.3 mg/kg Fe and 0.38 mg/kg Cu for Coca Cola® and 73 mg/kg Fe and 0.96 mg/kg Cu for the DTPA method. Besides the better results in extracting available micronutrient fractions from soils, further advantages of Coca Cola® as an extractant are its ubiquitous availability and readiness for use but also its easy and safe handling and the fact that the procedure has no harmful impacts on environment.