Lianhua Technology LH-NO3-P11 High-Range Nitrate-Nitrogen Test Strip

Overview

The Lianhua Technology LH-NO3-P11 High-Range Nitrate-Nitrogen Test Strip is a field-deployable, colorimetric analytical tool engineered for rapid, on-site quantification of nitrate-nitrogen (NO₃⁻-N) in water samples. Based on the principle of diazotization-coupling reaction—where nitrate is reduced to nitrite under acidic conditions and subsequently coupled with a chromogenic reagent to form a stable azo dye—the test strip delivers visual absorbance-based concentration estimation across an extended linear range. Designed specifically for environmental emergency response, mobile laboratory units, wastewater treatment plant field audits, and rural water safety screening, the LH-NO3-P11 eliminates dependency on benchtop spectrophotometers or wet chemistry setups while maintaining methodological consistency with standard EPA Method 353.2 and ISO 7890-3 for nitrate determination.

Key Features

• High-range detection capability: Optimized for nitrate-nitrogen concentrations from 10 to 200 mg/L NO₃⁻-N, bridging the gap between conventional low-range strips (0–10 mg/L) and laboratory-grade instrumentation.
• Visual colorimetric readout: Integrated calibrated color scale printed directly onto the test card enables immediate, instrument-free interpretation with ≤±15% relative error under controlled lighting conditions (CIE D65 illuminant).
• Uniform reagent impregnation: Manufactured using precision-controlled capillary deposition technology to ensure homogeneous distribution of sulfanilamide and N-(1-naphthyl)ethylenediamine dihydrochloride (NED), minimizing edge effects and inter-strip variability.
• Rapid assay kinetics: Full color development achieved within 90 seconds at 20–25°C; stable endpoint maintained for ≥5 minutes to accommodate sequential sample evaluation.
• Robust packaging architecture: Individually foil-laminated pouches with desiccant sachets guarantee shelf life of 24 months when stored at 2–30°C and <60% RH—validated per ICH Q1A(R2) stability protocols.
• Operator-independent workflow: Requires only three steps—dip, wait, compare—with no pipetting, timing devices, or calibration solutions needed, supporting deployment by field technicians with minimal training.

Sample Compatibility & Compliance

The LH-NO3-P11 strip demonstrates reliable performance in clarified surface water, groundwater, treated effluent, and potable water matrices. Turbidity up to 50 NTU and chloride concentrations ≤500 mg/L do not significantly interfere with the diazotization reaction. Cross-reactivity with nitrite is mitigated by inclusion of a selective nitrate-reduction catalyst layer; residual nitrite interference is <5% at 1 mg/L NO₂⁻-N. The product conforms to GB/T 5750.5-2023 (China National Standard for Drinking Water Quality Testing Methods) and supports compliance with WHO Guidelines for Drinking-water Quality (4th ed.) provisional guideline values for nitrate. Batch-certified reference materials traceable to NIST SRM 3189 (Nitrate in Water) are used during production QC.

Software & Data Management

While the LH-NO3-P11 operates as a standalone visual tool, optional digital integration is supported via Lianhua’s free “LH-Scan” mobile application (iOS/Android). Using standardized RGB capture under defined ambient light conditions, the app performs pixel-intensity mapping against NIST-traceable color reference libraries and exports CSV-formatted reports compliant with ISO/IEC 17025 documentation requirements. Audit trails—including timestamp, GPS coordinates, operator ID, and image metadata—are retained locally and exportable for GLP-aligned recordkeeping. No cloud storage is enabled by default; all data remains on-device unless explicitly exported by authorized users.

Applications

• Emergency response monitoring following agricultural runoff events or fertilizer spill incidents
• Routine surveillance of drinking water sources in decentralized rural supply systems
• Pre-screening of influent/effluent streams prior to advanced nitrogen removal process optimization
• Field validation of online nitrate analyzers during commissioning or maintenance intervals
• Educational demonstrations of nutrient cycling and eutrophication dynamics in environmental science curricula
• Regulatory self-monitoring under local discharge permits requiring periodic nitrate verification

FAQ

What is the shelf life of unopened LH-NO3-P11 test strips?

Unopened foil pouches retain full performance for 24 months when stored between 2°C and 30°C with relative humidity below 60%.
Can the strips be used in seawater or high-salinity groundwater?

Performance is validated for chloride ≤500 mg/L; samples exceeding this threshold require dilution with deionized water and correction for dilution factor.
Is there a documented correlation between LH-NO3-P11 results and laboratory spectrophotometric analysis?

Yes—multi-site validation studies (n=127 paired samples) show R² = 0.986 versus UV-Vis at 540 nm (EPA 353.2), with mean bias of +2.3 mg/L NO₃⁻-N across the 10–200 mg/L range.
Does the test detect nitrate exclusively, or does it respond to other nitrogen species?

The assay is specific for nitrate-nitrogen; ammonium, organic nitrogen, and nitrite produce negligible signal under standard operating conditions.
Are the strips compatible with digital image-based quantification tools beyond LH-Scan?

Third-party colorimetric analysis platforms may be used if calibrated against Lianhua’s certified color chart (Cat. No. LH-CAL-NO3-2023); however, Lianhua does not validate or support non-LH-Scan software algorithms.