Norm

ISO/DIS 19746:2016 en

Determination of urea content in urea-based fertilizers by high performance liquid chromatography (HPLC)

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Over deze norm

Status Ontwerp
Aantal pagina's 14
Commissie Meststoffen
Gepubliceerd op 25-01-2016
Taal Engels
Urea is the most widely used source of nitrogen fertilizers worldwide and is used in a variety of forms such as pure urea, in combination with other nutrients, in complex fertilizers, and as reacted or modified ureas1. Due to the rapid hydrolysis of urea in the environment, especially when applied at the soil surface2, efforts have been made to modify urea to slow down this loss process. Slow release nitrogen fertilizers such as methylene urea compounds, controlled release N fertilizers such as sulfur coated urea (SCU) or polymer coated urea (PCU), and stabilized N fertilizers containing additives (urease inhibitors, and nitrification inhibitors) are examples of products aimed at containing the rapid hydrolyses of urea in the soil. Accurate determination of urea in urea-based fertilizers is desirable for regulatory and product quality purposes. This is especially true for those fertilizers in which the urea content is physically or chemically modified. Most of these modified fertilizers contain some amounts of free and unreacted urea which is readily available N and therefore could not be accounted as part of the slow or controlled release N component 4. This international standard specifies the test procedure for determining the urea content in urea-based fertilizers, including urea, urea aldehydes [methylene urea fertilizers, isobutylenediurea (IBDU), crotonylidenediurea (CDU)], urea Triazone fertilizers, urea ammonium nitrate (UAN), sulfur and polymer coated urea (SCU & PCU), as well as compound fertilizers containing urea. The method is based on High Performance Liquid Chromatography (HPLC). The proposed method is an extension of the AOAC Official Method 2003.14 which was collaboratively studied for the ‚ÄúDetermination of Urea in Water-Soluble Urea-Formaldehyde Fertilizer Products and in Aqueous Urea Solutions‚ÄĚ in 2003. The method was published in the Journal of AOAC in 20043and was granted the First Action in 2003 and the Final Action in 2008. This method also applies to the determination of biuret content in urea containing fertilizer with the results published in the J. AOAC in 20144. This method was adopted by the International Organization for Standardization (ISO) as a Committee Draft (ISO-CD 18643) in 2014, and after review and the Ring Tests Analyses5. Note: This HPLC method can also be utilized to analysis CDU and IBDU contents within those above-mentioned fertilizers.

Details

ICS-code 65.080
Nederlandse titel Determination of urea content in urea-based fertilizers by high performance liquid chromatography (HPLC)
Engelse titel Determination of urea content in urea-based fertilizers by high performance liquid chromatography (HPLC)

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