DIN EN 16651 : 2015 Title: Fertilizers - Determination of N-(n-Butyl)thiophosphoric acid triamide (NBPT) and N-(n-Propyl)thiophosphoric acid triamide (NPPT) - Method using high-performance liquid chromatography (HPLC) Year: 2015 Publisher: DIN Media GmbH Availability: Within 1-2 working days