standard,nitrate concentration µmol/L,silicic acid concentration µmol/L                      ,nitrite concentration µmol/L,phosphate concentration µmol/L,ammonium concentration µmol/L
Standard 1,"2.69","4.45","0.11","0.32","0.42"
Standard 2,"5.38","8.9","0.22","0.63","0.83"
Standard 3,"10.76","17.8","0.43","1.26","1.66"
Standard 4,"21.30","35.61","065","1.90","2.49"
Standard 5,"42.16","71.21","0.87","2.53","3.33"