Ammonium sulfate is a commonly used as a nitrogen fertilizer. Sulfamic acid and ammonium thiocyanate may be contaminated during production of ammonium sulfate and they are known to cause a disturbance in plant germination. In this application, a standard solution of sulfamic acid and ammonium thiocyanate, and sample solution including standards were analyzed using IC NI-424, an anion analysis column according to the 2016 testing methods for fertilizers. It was confirmed that sulfamic acid and ammonium thiocyanate were measured without any influence of impurities in the sample solution including standards.
Sample preparation:
1. 1500ug each of sulfamic acid and ammonium thiocyanate were added to ammonium sulfate.
2. The sulfate was dissolved by water and make up to 100mL with water.
3. The solution was diluted with water by 12.5 times and filtered.
Sample : 20μL
Standard solution (Sulfamic acid and Ammonium thiocyanate 3mg/L each in H2O)
Sample solution including standards (Sulfamic acid and Ammonium thiocyanate 1.2mg/L each in 800mg/L Ammonium Sulfate solution)
1. Sulfamate
2. Thiocyanate
Column : Shodex IC NI-424 (4.6mmI.D. x 100mm) Eluent : 0.5mM Phthalic acid + 4.0mM p-Hydroxybenzoic acid + 0.9mM Sodium 1-Octanesulfonate + 2.0mM Sodium 1-Hexanesulfonate + 100mM Boric acid aq. Flow rate : 1.0mL/min Detector : Non-suppressed coductivity Column temp. : 58°C