文摘
The aim of this research is to develop an analytical methodology for the determination of complexedelement in fertilizers and, then, to obtain an adequate criteria for the inclusion of these products inEuropean Regulations on Fertilizers. This paper compares the CEN method EN 13366:2001, basedon the retention of the cations into a sulfonated resin, and an AOAC modified method, based on theprecipitation of the inorganic forms at pH 9. A limited interlaboratory trial was carried out to demonstratethe applicability of the AOAC modified method and to study the effect of the removal of organiccompounds and the addition of a matrix modifier solution before the element quantification. Then, aglobal interlaboratory trial was developed to evaluate the validation and quality parameters of themethod. As a second objective, the AOAC modified method was applied to the determination of thecomplexing capacity of complexing agents based on lignosulfonates and amino acids. The AOACmodified method was the choice methodology because it is adequate for the determination ofcomplexing capacity of micronutrients in fertilizer.