Hanna Instruments HI 83214 - Manual (Page 54)

54
INTERFERENCES
Interference may be caused by:
Arsenate at any level
Silica above 50 mg/L
Sulfide
above 9 mg/L.
To eliminate sulfide: add Bromine Water drop-wise until a pale yellow color develops; remove Bromine
Water excess by adding Phenol solution drop-wise.
Turbidity and suspended matter in large amounts may cause interference because the strongly acidic
reaction conditions may dissolve suspended matter or cause desorption of phosphates from particles. Before
measurement, turbidity or suspended matter should be removed by treatment with active carbon and by
prior filtration.
Phosphorus, Acid Hydrolyzable