GOST 30181.7-1994 Mineral fertilizers. Method for determination of total mass fraction of nitrogen in compound fertilizers (in ammonium and amide forms, using hypochlorite method)
1994GOST 30181.1-1994 Mineral fertilizers. Method for determination of total overall mass fraction of nitrogen in compound fertilizers (in ammonium and amide forms, with deammoniation)
1975GOST 20851.1-1975 Mineral fertilizers. Methods for determination of nitrogen content