FOSS Kjeltec™ 9 Distillator Semi-Automatic Kjeldahl Nitrogen Distillation Unit

Overview

The FOSS Kjeltec™ 9 Distillator is a semi-automatic steam distillation unit engineered for precision and reliability in Kjeldahl nitrogen analysis. It operates on the principle of controlled steam distillation—where alkalized digestate is subjected to saturated steam under regulated pressure and temperature conditions, enabling quantitative transfer of ammonia into a boric acid trapping solution. This physical-chemical separation process forms the analytical foundation for total nitrogen, protein, ammonium-nitrogen, and other nitrogen-containing analytes across diverse matrices. Designed for integration within validated laboratory workflows, the Kjeltec™ 9 Distillator serves as the core distillation module in classical Kjeldahl methodology and extends functionality to alternative applications including volatile acidity determination, cation exchange capacity (CEC) analysis, and volatile basic nitrogen (VBN) quantification. Its robust architecture supports routine use in food safety, agricultural quality control, environmental monitoring, pharmaceutical QC, and soil science laboratories where regulatory compliance and method traceability are critical.

Key Features

• Optimized steam generation system delivering consistent, pulse-free steam flow with adjustable power output (0–100%) to accommodate varying sample loads and matrix complexities
• Corrosion-resistant fluidic path constructed from high-purity PTFE, borosilicate glass, and chemically inert stainless steel components—ensuring long-term stability during repeated exposure to strong alkalis and acidic condensates
• Integrated real-time status monitoring via intuitive LED indicators and tactile feedback controls—enabling immediate recognition of operational phases (preheat, distillation, rinse, cooldown)
• Modular design supporting seamless upgrade paths: compatible with FOSS digestion modules for end-to-end Kjeldahl workflow integration, and configurable for coupling with potentiometric titrators to form fully automated distillation–titration sequences
• Thermal safety interlocks, overpressure relief valves, and automatic steam cutoff upon completion or anomaly detection—meeting IEC 61010-1 requirements for laboratory electrical equipment safety

Sample Compatibility & Compliance

The Kjeltec™ 9 Distillator accommodates a broad spectrum of sample types—including solid foods (cereals, meat, dairy), semi-solid matrices (slurries, pastes, fermented products), liquid samples (milk, beverages, digested wastewater), soils, plant tissues, and pharmaceutical excipients. Its calibrated sample weight ranges (0.2–2 g solids; 2–5 g semi-solids; 10–25 g liquids) align with AOAC Official Methods of Analysis (e.g., 984.13, 981.10), ISO 8968 (milk protein), ISO 1871 (cereals), EPA Method 350.1 (wastewater nitrogen), DIN 10492 (foodstuffs), and Chinese Pharmacopoeia General Chapter 0704. All operational parameters—including steam temperature profile, condensate cooling efficiency, and distillate collection timing—are validated to ensure ≥99.5% nitrogen recovery across certified reference materials (CRMs) such as BCR®-185R (wheat flour) and NIST SRM 8414 (bovine liver).

Software & Data Management

While the Kjeltec™ 9 Distillator operates as a stand-alone semi-automatic instrument without embedded software, it is fully compatible with FOSS’s Kjeltec™ Suite software when connected to an external PC via RS-232 or USB-to-serial interface. The software enables method parameter storage, run logging, electronic signature support, and audit trail generation compliant with FDA 21 CFR Part 11 and EU Annex 11 requirements. Each distillation cycle records timestamped metadata—including start/stop times, actual steam-on duration, operator ID, and instrument serial number—facilitating GLP/GMP-aligned data integrity and retrospective review. When paired with a certified potentiometric titrator (e.g., Metrohm 905 Titrando), full sequence automation—including endpoint detection, calculation of %N and %protein (using standard conversion factors), and PDF report export—is achievable without manual intervention.

Applications

• Quantitative determination of total nitrogen and crude protein in cereals, legumes, animal feed, and dairy products per AOAC and ISO standards
• Ammonium-nitrogen analysis in fertilizers, wastewater effluents, and soil extracts following ISO 14256-1 and EPA 350.1
• Volatile basic nitrogen (VBN) assessment in fish and seafood quality control protocols (ISO 11014, GB/T 5009.44)
• Cation exchange capacity (CEC) measurement in clay-rich soils using ammonium acetate extraction and Kjeldahl distillation
• Volatile acidity determination in wine, vinegar, and fermented beverages per OIV and AOAC methods

FAQ

Can the Kjeltec™ 9 Distillator be used without a FOSS digestion unit?
Yes—it accepts pre-digested samples in standard Kjeldahl digestion tubes (e.g., 300 mL or 500 mL borosilicate glass) and functions independently as a dedicated distillation module.
Is the instrument compatible with third-party titrators?
Yes—via standardized analog voltage output (0–10 V) and digital TTL-level trigger signals, enabling synchronization with most modern potentiometric titrators from Metrohm, Hanna, or Thermo Fisher.
What maintenance intervals are recommended for optimal performance?
Daily rinsing of the distillation chamber and condenser; monthly inspection of steam inlet seals and alkaline reagent delivery tubing; annual calibration verification using CRM-certified nitrogen solutions.
Does the system support multi-user access with role-based permissions?
Not natively—but when operated through Kjeltec™ Suite software on a networked PC, user authentication, permission levels, and electronic signatures can be enforced per organizational SOPs.
How is method validation documented for regulatory submissions?
FOSS provides IQ/OQ documentation templates aligned with ISO/IEC 17025 and GxP expectations, including blank testing, linearity verification (0.1–210 mg N), intermediate precision assessment (n=6 replicates), and recovery studies across representative matrices.