tandard solutions. However, coexisting substances will

cause inaccurate results. The list below reports substances concentrations under which ones

interferences are insignificant:

< 1000 mg/L : Al3+, As3+, B3+, Ba2+, Ca2+, Co2+, Cl-, F-, I-, K+, Mg2+, Mn2+, Na+, NH4+, Ni2+, NO2-, NO3-,

PO43-, SO42-, Zn2+, Phenol

< 500 mg/L : CN-, Cu2+, Pb2+

< 250 mg/L : Cd2+, Fe3+, Mo6+

< 100 mg/L : Ag+, Cr3+