I. Benchtop Laboratory Instruments (Compatible with Both Nessler and Salicylic Acid Methods Simultaneously)

(1) Model 5B-6D(V10) Intelligent Ammonia Nitrogen Analyzer (Dedicated Ammonia Nitrogen Unit)

• Pre-stored multiple high/low-range calibration curves for Nessler method and salicylic acid method, with one-touch method switching
• Dual wavelengths: 420 nm (for Nessler method) / 610 nm (for salicylic acid method); compatible with both test tube colorimetry and cuvette colorimetry
• Applicable to wastewater, surface water, tap water, aquaculture water and chemical wastewater

(2) LH-C600 Multi-Parameter Integrated Analyzer (COD / Ammonia Nitrogen / Total Phosphorus / Total Nitrogen)

II. Matching Reagents (Pre-formulated Ready-to-Use, Two Series for Nessler and Salicylic Acid Methods Respectively)

(1) Nessler Method Reagents (Measuring Range: 0~10 mg/L)

• LH-N2N3 solid reagent: Requires manual dissolution; sufficient for 100 tests. Shelf life: 2 years for solid powder, 1 month after preparation into solution. Cost-effective choice for high-volume batch testing.
• LH-YN2N3 liquid reagent: Ready for direct use after opening bottle; 12-month shelf life, ideal for small-batch laboratory analysis.
• LH-NH3-YZ11 pre-capped tube reagents: Pre-filled reaction tubes; simply add sample, shake and stand for reaction. Available in packs of 25 or 50 tubes, eliminating preparation errors. Widely adopted by third-party testing institutions and for rapid screening.

(2) Salicylic Acid Method Reagents (High and Low Ranges Available)

• Low-range pre-capped tubes LH-NH3-YZ22: Range 0.02~2.5 mg/L, specially designed for surface water, drinking water and river monitoring.
• High-range pre-capped tubes LH-NH3-YZ21: Range 0.5~50 mg/L, suitable for low-strength industrial wastewater and reclaimed water reuse.
• Complete matching liquid reagent set: LH-NH3-SAH-100
  Comprehensive package containing flocculation precipitation reagents (zinc sulfate, sodium hydroxide), sodium thiosulfate dechlorinating agent, ammonia-free water, ammonia nitrogen standard solution and filtration consumables; no extra purchases required.

III. Solutions for Common Interferences (Lianhua Matching Countermeasures)

1. Residual chlorine interference: Eliminate with matched sodium thiosulfate solution
2. Turbidity caused by suspended solids and heavy metals: Pre-treatment using flocculation precipitation kit
3. High organic content (sodium acetate, carbon-source wastewater): Prioritize low-range salicylic acid method with appropriate sample dilution
4. Turbid color development and invalid readings: Dilute sample, re-filter or replace with fresh reagents

IV. Solution Selection Recommendations

1. For factory wastewater treatment stations, daily large sample batches and fast testing demands → Nessler pre-capped reagent LH-NH3-YZ11
2. For river water, tap water, groundwater and environmental online monitoring scenarios avoiding mercury-containing reagents → Same analyzer paired with high/low-range salicylic acid reagents LH-NH3-SAH and LH-NH3-SAL
3. For portable on-site patrol inspection and sewage outlet spot checks → LH-C600 portable multi-parameter analyzer supporting both testing methods
4. For third-party laboratories requiring compliant test reports: Instrument calibration curves comply with national standards HJ 535 and HJ 536; test data valid for internal self-inspection and pollutant discharge management.