... sulfides react with N, N-diethyl-p-phenylenediamine to form a blue complex.The range of the determination: 0.02~0 ... with colorimetric chart, come out a result.Note: SO32-, S2O32-, NO3-, SCN-, I-, Pd2+, Hg2+, Cu2+ will affect the result.4. ... productsNitrite test kit LH-P01Ammonia nitrogen test kit LH-P02Ozone (with residual chlorine) in water test kit LH-P03DPD ozone in water test kit LH-P04DPD ...