BUCHI K-365 Kjel Line Automated Kjeldahl Nitrogen Determinator
| Brand | BUCHI |
|---|---|
| Origin | Switzerland |
| Manufacturer | BUCHI AG |
| Instrument Type | Automated Kjeldahl Nitrogen Determinator |
| Recovery Rate | ≥99.5% |
| Power Consumption | 2100 W |
| Dimensions (L×W×H) | 320 × 400 × 730 mm |
| Weight | 23 kg |
| Electrical Supply | 220–240 VAC ±10%, 50/60 Hz |
| Safety Certifications | CE, CSA |
| Repeatability | RSD <0.8% |
| Nitrogen Detection Range | 0.02–220 mg N |
| Cooling Water Management | Intelligent Flow Control with Auto-Shutoff |
| Steam Power Control | Adjustable 10–100%, Programmable Steam Gradient |
| Safety Systems | Dual-flow cooling water sensor, steam generator pressure monitoring, sample tube presence detection, transparent safety shield with interlock, reagent/waste/water level sensing |
| Voltage Stabilization | Integrated line regulator for consistent steam output |
Overview
The BUCHI K-365 Kjel Line is a fully automated, modular Kjeldahl nitrogen determinator engineered for precision, safety, and long-term operational reliability in regulated analytical laboratories. Based on the classical Kjeldahl method—comprising digestion, distillation, and titration—the K-365 executes the distillation step with high reproducibility and traceable compliance. Its core measurement principle relies on quantitative steam distillation of ammonium ions liberated from digested samples, followed by acid trapping and back-titration or direct potentiometric titration. Designed and manufactured in Flawil, Switzerland, the system meets stringent requirements for food, feed, environmental, pharmaceutical, and agricultural testing where nitrogen content directly correlates with protein quantification (e.g., % protein = %N × conversion factor). The instrument operates under ISO 8968, AOAC 981.10, ASTM D1122, and USP , supporting GLP/GMP workflows through audit-ready operation logs and hardware-enforced safety protocols.
Key Features
- Modular architecture enabling configuration as EasyKjel (entry-level), BasicKjel (standard automation), or MultiKjel (full integration with digestion and titration modules)
- Intelligent cooling water management: flow-activated condenser inlet, auto-shutoff pre- and post-distillation—reducing water consumption by ~20% without compromising condensation efficiency
- Programmable steam gradient control (10–100%) to suppress foaming in high-fat or viscous matrices such as dairy products, meat homogenates, or wastewater sludge
- Integrated voltage stabilizer ensuring consistent steam generation despite ±10% mains fluctuation—critical for maintaining distillation kinetics and recovery accuracy
- Comprehensive hardware safety suite: transparent polycarbonate safety shield with magnetic interlock, real-time monitoring of cooling water flow rate, steam generator pressure, sample tube insertion status, and reagent/waste/water tank levels
- Touchscreen HMI with intuitive workflow navigation, multilingual support (EN/DE/FR/ES), and context-sensitive help—designed for minimal training overhead in multi-user lab environments
Sample Compatibility & Compliance
The K-365 accommodates standard 100–500 mL Kjeldahl digestion tubes (including borosilicate glass and quartz variants) and supports both manual and robotic sample loading via optional autosampler integration. It complies with international regulatory frameworks including FDA 21 CFR Part 11 (when paired with BUCHI LabX software), EU Annex 11, and ISO/IEC 17025 requirements for method validation. All safety-critical functions—including emergency shutdown upon barrier opening or low coolant detection—are hardware-locked and independently verifiable. The system’s ≥99.5% nitrogen recovery rate and RSD <0.8% are validated per AOAC 992.15 using certified reference materials (e.g., BCR-68, NIST SRM 8414), ensuring data integrity across batch analyses.
Software & Data Management
When operated with BUCHI LabX LIMS-ready software, the K-365 provides full electronic record keeping, user access control (role-based permissions), digital signature capability, and automated report generation compliant with ALCOA+ principles. Audit trails log all parameter changes, method executions, maintenance events, and safety interventions with immutable timestamps. Data export adheres to ASTM E1384 and ISO 15197 standards, supporting CSV, PDF, and XML formats for seamless integration into enterprise quality systems (e.g., SAP QM, TrackWise, Veeva Vault).
Applications
The K-365 delivers robust performance across diverse sectors: crude protein determination in cereals, legumes, and animal feed per AOAC 984.13; total Kjeldahl nitrogen (TKN) in municipal wastewater per EPA 351.2; casein quantification in dairy powders per ISO 8968-1; and non-protein nitrogen (NPN) assessment in fertilizers per ISO 5315. Its programmable distillation profiles accommodate challenging matrices—including fermented beverages, soil extracts, and pharmaceutical excipients—without manual intervention or method recalibration.
FAQ
What safety certifications does the K-365 hold?
CE and CSA marks confirm compliance with IEC 61010-1 for laboratory electrical equipment safety.
Can the K-365 be integrated into an existing LIMS environment?
Yes—via LabX software with OPC UA or REST API connectivity, supporting bidirectional data exchange and electronic batch records.
Is method validation documentation provided?
BUCHI supplies IQ/OQ documentation packages, along with AOAC-validated recovery and precision data for common matrices.
Does the system require external cooling water chillers?
No—the intelligent flow control enables use with standard tap water; chiller integration is optional for high-throughput labs with ambient temperature fluctuations.
How is user training delivered?
On-site or remote installation qualification includes hands-on operation, preventive maintenance, and troubleshooting workshops conducted by BUCHI-certified application specialists.
