Raykol RK-8900 Fully Automated Kjeldahl Nitrogen Analyzer
| Brand | Raykol |
|---|---|
| Origin | Fujian, China |
| Manufacturer Type | Direct Manufacturer |
| Instrument Type | Kjeldahl Nitrogen Analyzer |
| Automation Level | Fully Automated |
| Nitrogen Determination Range | 0.1–240 mg N |
| Distillation Time Setting Range | 10–9990 s |
| Repeatability | ≤0.5% RSD |
| Sample Weight Capacity | ≤5.00 g (solid), ≤20 mL (liquid) |
| Nitrogen Recovery Rate | 99–101% |
| Power Consumption | 2000 W |
| Dimensions (L×W×H) | 500 mm × 460 mm × 710 mm |
| Sample Capacity | 40-position auto-sampler |
| Integrated Refrigeration System | Standard |
| Data Storage Capacity | Up to 1,000,000 records |
| Interface Options | USB, LAN, RS232, CAN, Wi-Fi, Ethernet, Analytical Balance, Chiller Control |
Overview
The Raykol RK-8900 Fully Automated Kjeldahl Nitrogen Analyzer is an engineered solution for precise, high-throughput nitrogen quantification in compliance with ISO 8968, AOAC 981.10, ISO 1871, and ASTM D1122—standards governing Kjeldahl-based nitrogen determination in food, feed, agricultural soils, dairy products, fertilizers, and environmental samples. Based on the classical Kjeldahl digestion–distillation–titration principle, the RK-8900 automates all three core stages without manual intervention: sample introduction, alkaline distillation under controlled steam flow, and potentiometric or colorimetric back-titration. Its architecture integrates a 40-position carousel autosampler, sealed reagent delivery with level sensing, programmable steam generation (1–100% adjustable), and real-time thermal monitoring across digestion, distillation, and condensation zones. Unlike semi-automated systems requiring post-digestion tube transfer, the RK-8900 accepts pre-digested sample racks directly—eliminating handling errors and cross-contamination risks while enabling unattended overnight operation.
Key Features
- Fully integrated 40-sample workflow: Accepts standard 300-mL Kjeldahl digestion tubes mounted on a rectangular rack; no manual tube relocation required between digestion and analysis phases.
- Dual-mode sample introduction: Supports both batch-loaded rack insertion and single-tube mode for flexibility in low-throughput validation or method development.
- Intelligent reagent management: Built-in reagent reservoirs equipped with ultrasonic liquid-level sensors ensure consistent dosing of NaOH, boric acid, and titrant; automatic line flushing prevents crystallization and blockage.
- Simultaneous distillation and titration: Enables concurrent steam generation and endpoint detection—reducing cycle time by up to 35% versus sequential protocols.
- High-fidelity titration optics: Triple-channel RGB coaxial photometric sensor system provides broad-spectrum color discrimination (pH 4.5–6.5), minimizing interference from sample matrix discoloration.
- Self-calibrating titrant delivery: Internal standardization routine corrects for titrant concentration drift using certified reference solutions, ensuring long-term volumetric accuracy per ISO/IEC 17025 requirements.
- Comprehensive safety architecture: Includes dual-position digestion tube detection, door-interlocked motion control, steam boiler overtemperature cutoff (≥220 °C), pressure relief valve (max 0.35 MPa), and real-time sample temperature monitoring with auto-shutdown at >120 °C.
- Modular refrigeration unit: Integrated chiller reduces cooling water consumption by >90% compared to tap-water condensers—meeting ISO 14001 energy-efficiency benchmarks.
Sample Compatibility & Compliance
The RK-8900 accommodates heterogeneous matrices including cereal flours, meat homogenates, silage, compost, wastewater sludge, and polymerized nitrogenous compounds. Solid samples up to 5.00 g and liquids up to 20 mL are processed within standardized Kjeldahl tubes conforming to DIN 12677. The system supports full audit trail functionality aligned with FDA 21 CFR Part 11: electronic signatures, user-access tiering (administrator/operator/analyst), immutable data logging with timestamped metadata, and encrypted database export. All calibration, blank correction, and recovery verification steps are traceable to NIST-traceable standards. Method templates may be configured to apply matrix-specific protein conversion factors (e.g., 6.25 for cereals, 6.38 for dairy, 5.70 for wheat gluten), with lookup tables stored and version-controlled in the onboard database.
Software & Data Management
Controlled via a 10-inch industrial-grade capacitive touchscreen running Windows IoT Enterprise, the RK-8900’s embedded software provides unified management of the analyzer, autosampler, and chiller subsystems. It features GLP-compliant reporting: automated PDF report generation with embedded chromatograms (if optional UV detector installed), QC charts (X-bar/R), and statistical summaries (mean, SD, RSD, recovery %). Data storage exceeds 1 million test records with configurable retention policies. Export options include CSV, XML, and LIMS-ready HL7 v2.5 messages via TCP/IP. Remote diagnostics and firmware updates are supported over secure HTTPS or VPN tunnels. All analytical parameters—including distillation time, steam intensity, titrant volume, and blank subtraction logic—are programmable per method and locked with digital signature authentication.
Applications
- Protein content certification in ISO/IEC 17025-accredited food testing laboratories
- Feed formulation QA/QC for aquaculture and livestock nutrition monitoring
- Nitrogen balance studies in agricultural soil health assessments (ISO 11261)
- Regulatory compliance testing for fertilizer labeling (EPA 503, EU Fertilising Products Regulation)
- Method validation and reference material characterization in NMIs and metrology institutes
- Research-scale nitrogen metabolism profiling in plant physiology and biotechnology labs
FAQ
Does the RK-8900 require external cooling water?
No—the instrument includes a factory-integrated closed-loop refrigeration system rated for continuous operation at ambient temperatures up to 35 °C.
Can the RK-8900 interface with third-party LIMS platforms?
Yes—via configurable HL7 v2.5 messaging over Ethernet or RS232; custom API integration is available under NDA.
What digestion equipment is compatible with the 40-position rack?
The RK-8900 is designed to accept racks from Raykol’s RK-2000 series 40-hole digestion blocks, but also accommodates standard DIN-compliant racks with minor mechanical adaptation.
How is blank correction implemented?
The system performs automatic blank titration before each batch, stores historical blank values with decay-weighted averaging, and applies dynamic subtraction during sample calculation.
Is the titration system compliant with pharmacopeial requirements?
Yes—potentiometric and photometric titration modules meet USP <21>, EP 2.2.20, and JP 2.05 specifications for volumetric analysis accuracy and repeatability.
