HePu KN620 Automated Kjeldahl Nitrogen Determinator
| [Brand | HePu (Jihepu) |
|---|---|
| Origin | Shandong, China |
| Model | KN620 |
| Nitrogen Range | 0.1–250 mg N |
| Distillation Time | <5 min/sample |
| Repeatability | ≤0.5% RSD |
| Sample Capacity | ≤5 g solid or ≤20 mL liquid |
| Recovery Rate | ≥99.5% |
| Power | 1300 W |
| Dimensions (L×W×H) | 500 × 410 × 850 mm] |
Overview
The HePu KN620 Automated Kjeldahl Nitrogen Determinator is a fully integrated, CE-compliant benchtop system engineered for precise, high-throughput nitrogen quantification in accordance with ISO 8968-1, AOAC 984.13, and ASTM D1122–17. It implements the classical Kjeldahl method—comprising acid digestion (in concentrated H₂SO₄), alkaline steam distillation, boric acid trapping, and potentiometric or colorimetric endpoint detection—to deliver traceable, regulatory-grade nitrogen and crude protein results. Designed for laboratories requiring GLP/GMP alignment, the KN620 delivers sub-milligram nitrogen resolution across diverse matrices without operator-dependent variability. Its architecture separates thermal, hydraulic, pneumatic, and electrical subsystems to minimize cross-interference and ensure long-term metrological stability under continuous operation.
Key Features
- Fully automated workflow: acid addition, alkali dosing, steam distillation, titration, digestion tube rinsing, waste evacuation, data logging, calculation, and report generation—all executed without manual intervention.
- Dual-mode distillation: configurable pre-steam dilution mode (to homogenize viscous or crystalline digests) and delayed distillation mode (for controlled reaction kinetics); steam flow rate adjustable from 1% to 100% in real time.
- Patented anti-crystallization alkaline pump design prevents NaOH salt deposition, eliminating maintenance downtime and ensuring >10,000-cycle reliability.
- Intelligent steam-assisted dilution: steam introduced immediately after water addition agitates the digest, enabling safe, uniform dilution of concentrated H₂SO₄ prior to alkali injection—reducing exothermic shock and improving nitrogen recovery consistency.
- SuperFast adaptive titration: real-time volume- and speed-modulated titration synchronized with distillation; endpoint determined via dynamic color-learning algorithm with user-adjustable hue/saturation thresholds.
- Bidirectional titration protocol: coarse titration followed by fine-titration step ensures ±0.01 mL precision at endpoint, critical for low-nitrogen samples (e.g., purified water, pharmaceutical excipients).
- 10-inch 16-bit true-color touchscreen with SmartOneKey™ interface; multi-level user authentication (admin/operator/technician) with audit-trail-enabled login and action logging per FDA 21 CFR Part 11 requirements.
- Comprehensive hardware safety: pressure relief valve, overtemperature cutoff, liquid level sensors, dry-run protection, safety door interlock, digestion tube presence detection, receiving cup overflow sensor, and optional reagent tank level monitoring.
Sample Compatibility & Compliance
The KN620 accommodates solid samples up to 5 g (e.g., cereal grains, feed pellets, soil composites) and liquid samples up to 20 mL (e.g., milk, urine, fermentation broth, wastewater). It supports analysis of ammonium salts, volatile fatty acids, and total alkalinity—extending utility beyond standard nitrogen assays. All wetted components are fabricated from PTFE, borosilicate glass, and 316 stainless steel to resist corrosion from aggressive reagents (H₂SO₄, NaOH, H₃BO₃). The system complies with IEC 61010-1 (electrical safety), ISO/IEC 17025:2017 (method validation framework), and supports full traceability for ISO 9001, ISO 14001, and BRCGS-certified laboratories.
Software & Data Management
Embedded firmware enables local storage of ≥2,000 test records with timestamp, operator ID, method parameters, raw titration curves, and final reports. Data export is supported via USB mass storage, RS-232 serial, Ethernet (LAN), or Wi-Fi—compatible with LIMS integration using standard CSV or XML formats. Cloud synchronization (via optional HePu CloudLink™ service) allows remote method deployment, real-time result dashboards, and cross-site audit review. Mobile access is enabled through dedicated iOS/Android applications and WeChat Mini Program integration, permitting status monitoring and emergency alerts without on-site presence.
Applications
The KN620 serves quality control and R&D laboratories in food & beverage (dairy, meat, plant-based proteins), agriculture (fertilizer efficacy, crop nutrient profiling), environmental testing (wastewater TN, sludge nitrogen load), pharmaceutical manufacturing (API purity, excipient nitrogen content), and academic research (soil biogeochemistry, enzymatic nitrogen turnover studies). Its ability to quantify ammoniacal-N, organic-N, and nitrate-N (after reduction) makes it suitable for nitrogen speciation workflows in regulatory compliance testing (e.g., EU Nitrates Directive, US EPA Method 350.1).
FAQ
What standards does the KN620 validate against?
It conforms to ISO 8968-1 (milk), AOAC 984.13 (general foods), ASTM D1122–17 (petroleum products), and GB/T 6423–2022 (Chinese national standard for feed).
Can the instrument be validated for 21 CFR Part 11 compliance?
Yes—user role management, electronic signatures, audit trail generation, and secure data encryption are natively implemented and documented in the IQ/OQ/PQ validation package.
Is external digestion equipment required?
No—the KN620 is a standalone distillation/titration unit; digestion must be performed separately using a compatible block digester or microwave system prior to loading digest tubes.
What maintenance intervals are recommended?
Alkali pump inspection every 6 months; steam generator descaling every 3 months (using citric acid solution); optical sensor cleaning before each batch; full calibration verification annually using certified KCl/NH₄Cl reference standards.
