A Comparison of the Extraction Methods used in the UK Nitrate Residues Monitoring Program
Abstract
It has been reported that significantly different nitrate levels may be obtained from the same crop at the same harvest when analysed by different laboratories. These differences may be due to the methods of analysis used by the laboratories, and in particular the extraction procedures that may be applied to extract nitrates from the crops. In this project a suitable homogenisation procedure for the preparation of samples was developed for preparation of samples to reduce this variability. Several nitrate extraction methods, including that described in BS EN 12014-2:1997, were evaluated. The BS method was subjected to a robustness test and then a collaborative trial involving 9 laboratories. Of the extraction
