prEN 18319

This document specifies a method for the extraction and determination of phosphonates (P-PO3) in fertilizers, liming materials and inhibitors using ion chromatography and conductivity detection (IC-CD).
This document is applicable to fertilizing product blends, where the blend is a mix of at least two of the following components, fertilizers, liming materials, soil improvers, growing media, inhibitors and plant biostimulants, and where the following category, fertilizers, liming materials and inhibitors, is the highest % in the blend by mass or volume, or in the case of liquid form, by dry mass.
If fertilizers, liming materials and inhibitors is not the highest % in the blend, the European Standard for the highest % of the blend applies. In case a fertilizing product blend is composed of components in equal quantity, the user decides which standard to apply.
NOTE  Variations in analytical methods for fertilizing product blends can lead to differing results as some components or matrix interactions can affect the outcome. Validation procedures have shown that developed standard methods are robust and reliable across diverse product compositions, but possible interferences and unexpected results when analysing fertilizing product blends are possible.