Shengaohua SH-50TN(V10) Total Nitrogen Analyzer

Overview

The Shengaohua SH-50TN(V10) Total Nitrogen Analyzer is a dedicated laboratory-grade spectrophotometric instrument engineered for accurate, reproducible quantification of total nitrogen (TN) in aqueous environmental samples. It operates on the alkaline potassium persulfate digestion–UV spectrophotometric principle: samples are subjected to high-temperature (123 ± 0.5 °C), precisely controlled oxidative digestion for 30 minutes to convert all nitrogen species—including organic nitrogen, ammonia, nitrite, and nitrate—into nitrate ions. Subsequent UV absorbance measurement at 220 nm enables direct concentration calculation using calibrated absorbance-to-concentration relationships. Designed for routine compliance monitoring and research-grade analysis, the SH-50TN(V10) meets core methodological requirements aligned with ISO 11905-1 (water quality — determination of nitrogen — part 1: total nitrogen by oxidation with alkaline persulfate), and supports laboratories working under GLP or municipal wastewater reporting frameworks.

Key Features

• Precisely regulated digestion module with PID-controlled heating and ±0.5 °C thermal uniformity across all six reaction positions, ensuring consistent oxidation efficiency and inter-sample comparability.
• Integrated dual-wavelength photometric system optimized for 220 nm detection with ≤0.001 A/10 min baseline stability—critical for low-concentration TN measurements near the 0.2 mg/L detection limit.
• Flexible calibration architecture: 4 pre-loaded standard curves compliant with common regulatory reference materials, plus 96 fully editable and savable user-defined curves for method adaptation or matrix-specific compensation.
• Robust hardware design featuring acid-resistant PTFE-coated chamber lining, transparent polycarbonate safety shield, and ergonomic molded housing for long-term durability in high-acid digest environments.
• Onboard Chinese-language LCD interface with intuitive menu navigation, real-time temperature/timer feedback, and direct concentration readout in mg/L—eliminating manual calculation errors.
• USB interface enables secure, audit-ready data export to external storage or LIMS-compatible spreadsheets; all measurement records include timestamp, curve ID, digestion parameters, and operator tag (if configured).

Sample Compatibility & Compliance

The SH-50TN(V10) is validated for use with surface water, groundwater, domestic and industrial wastewater, effluent from biological treatment units, and pretreated sludge supernatants. Sample matrices must be free of suspended solids >50 mg/L (centrifugation or filtration recommended prior to analysis). The instrument supports digestion protocols compatible with EPA Method 351.2 (Total Kjeldahl Nitrogen – Modified) and ISO 11905-1, and its performance characteristics—including ≤±5% accuracy and 0.01 mg/L resolution—meet reporting thresholds required by national discharge permits and municipal water quality surveillance programs. While not FDA 21 CFR Part 11-certified out-of-the-box, audit trails (via exported logs), user-access controls (via password-protected curve editing), and immutable measurement timestamps enable alignment with GLP documentation standards when integrated into documented SOP workflows.

Software & Data Management

No proprietary PC software is required for basic operation. All calibration, measurement, and data review occur via the embedded firmware. However, raw absorbance values, digestion parameters, curve coefficients, and result metadata are exportable in CSV format via USB. Each record contains: sample ID (user-entered), date/time stamp, selected curve index, measured absorbance, calculated concentration, and digestion completion flag. Internal memory retains ≥500 full test records with rollover protection. For laboratories implementing electronic record retention, exported files may be ingested into validated LIMS or ELN platforms supporting CSV ingestion and version-controlled method templates.

Applications

• Regulatory compliance testing for municipal wastewater treatment plants (WWTPs) reporting to local environmental authorities under discharge limits (e.g., China’s GB 18918-2002, EU Urban Wastewater Treatment Directive).
• Process control monitoring in activated sludge, MBR, and denitrification systems—tracking TN removal efficiency across influent, anoxic zone, and final effluent points.
• Research applications in environmental science departments assessing nitrogen cycling in constructed wetlands, agricultural runoff, or eutrophication studies.
• Quality assurance for industrial pretreatment units in textile dyeing, pharmaceutical manufacturing, and food processing facilities where TN load impacts downstream biological treatment viability.
• Educational use in undergraduate analytical chemistry and environmental engineering labs—demonstrating oxidation chemistry, Beer-Lambert law application, and QA/QC practices including spike recovery and duplicate analysis.

FAQ

What digestion reagent is required for the SH-50TN(V10)?
Alkaline potassium persulfate solution (typically 2–5% w/v, pH >12) is used. Users must prepare or procure certified reagent-grade persulfate and NaOH according to method specifications.
Can the instrument measure both total nitrogen and total phosphorus simultaneously?
No—the SH-50TN(V10) is dedicated solely to total nitrogen analysis. For combined TN/TP analysis, Shengaohua offers separate SH-50TP and integrated SH-50TN+TP configurations.
Is method validation documentation provided with the instrument?
Yes—a technical validation report including precision (RSD ≤3%), accuracy (recovery 95–105% for spiked natural waters), LOD/LOQ verification, and linearity (r² ≥0.999 over 0.2–20 mg/L) is supplied with each unit.
How often does the optical system require recalibration?
The photometer is factory-calibrated and requires no routine recalibration. Annual verification using NIST-traceable nitrate standards is recommended for auditable environments.
Does the device support external printer output?
No native parallel or serial printer interface is included; however, exported CSV files can be formatted and printed via standard office software on connected host computers.