Analysis,Nox concentration µmol/L,silicic acid concentration µmol/L,nitrite concentration µmol/L,phosphate concentration µmol/L,nitrate concentration µmol/L,ammonium concentration µmol/L CRM CC,,,,,, Certified range,31.58-32.08,87.99-88.98,0.11-0.12,2.12-2.16,31.47-31.96,Not determined "Measured values (n=26)",31.03±0.50,86.51±0.86,0.14±0.02,2.12±0.03,30.92±0.49,2.34±0.78 CRM CJ,,,,,, Certified range,15.55-15.97,39.49-40.31,0.02-0.04,1.21-1.25,15.54-15.96,Not determined "Measured values (n=8)",16.20±0.37,39.08±0.42,0.06±0.02,1.23±0.01,16.16±0.36,1.00±0.17