Peiou SKD-800 Automated Kjeldahl Nitrogen Determinator

Overview

The Peiou SKD-800 Automated Kjeldahl Nitrogen Determinator is a semi-automated benchtop instrument engineered for precise, reproducible quantification of total nitrogen content in organic matrices via the classical Kjeldahl digestion–distillation–titration methodology. Designed in accordance with ISO 8968-1, AOAC 981.10, and ASTM D1142 standards, the SKD-800 supports routine nitrogen analysis across food safety laboratories, agricultural testing centers, feed quality control facilities, environmental monitoring agencies, and biochemical R&D departments. Its operational principle relies on acid-catalyzed digestion of organic nitrogen into ammonium sulfate, followed by alkaline distillation to liberate ammonia, which is then captured in boric acid solution and quantified via titration. The system integrates robust process control logic to maintain stoichiometric integrity throughout sample preparation—ensuring high recovery rates and minimizing operator-induced variability.

Key Features

• Real-time dual-point temperature monitoring: continuous tracking of digestion cup surface temperature and condensate collector temperature, with automatic pause/resume functionality upon thermal threshold breach
• Dual-liquid-level safety architecture: redundant float and conductive sensors prevent dry-burn operation and ensure reliable reagent delivery during distillation
• Intermittent alkali dosing mechanism: precisely timed, pulsed addition of NaOH mitigates violent exothermic reactions and eliminates sample splashing or carryover
• Modular fluidic design: independent, externally mounted reagent reservoirs (H₂SO₄, NaOH, H₃BO₃, diluent) coupled with constant-pressure peristaltic pumps guarantee volumetric consistency and reduce cross-contamination risk
• ABS engineering-grade enclosure: one-piece molded chassis provides inherent resistance to concentrated sulfuric acid fumes and long-term corrosion exposure
• Adaptive power regulation: adjustable distillation heating (750–1500 W) enables optimized ammonia liberation across diverse sample matrices—from low-nitrogen cereals to high-protein dairy concentrates
• Manual/automatic mode switching: full operational transparency with real-time graphical display of digestion status, reagent volumes consumed, elapsed time, and active safety flags

Sample Compatibility & Compliance

The SKD-800 accommodates solid samples up to 6 g (e.g., ground grain, dried soil, powdered feed) and liquid samples up to 16 mL (e.g., milk, wastewater, enzyme solutions). It complies with GLP documentation requirements through built-in audit trails: all critical events—including reagent level warnings, coolant interruptions, door-open alerts, and temperature excursions—are timestamped and logged internally. Data export supports CSV format for integration into LIMS environments. While not FDA 21 CFR Part 11 compliant out-of-the-box, its event logging architecture facilitates validation under ISO/IEC 17025 and internal QA protocols requiring traceable instrument performance records.

Software & Data Management

The embedded control interface stores ≥100 customizable distillation programs—including programmable delay intervals (0–1800 s) for fertilizer analysis—and retains ≥1000 completed sample records with metadata (sample ID, date/time, N mass, recovery %, operator tag). All pre-distillation routines—preheating, rinsing, acid/alkali/boric acid dosing, and diluent addition—are fully automated and sequence-editable. No external PC or proprietary software is required; all configuration and review occur via the integrated 5.7-inch LCD panel with tactile navigation keys. Data can be exported via USB port for offline reporting or QA review.

Applications

The SKD-800 delivers validated nitrogen results for regulatory and quality assurance workflows including: crude protein estimation in animal feed (AOAC 984.13), total Kjeldahl nitrogen (TKN) in municipal wastewater (EPA 351.2), protein content verification in dairy products (ISO 8968-1), nitrogen balance studies in soil science, and purity assessment of pharmaceutical excipients. Its consistent 99.5%+ recovery rate and sub-0.5% RSD meet the precision thresholds specified in ISO 5725-2 for intermediate precision in accredited laboratories.

FAQ

Is the SKD-800 compatible with automated titration systems?
Yes—its standardized 15–30 mL/min condensate flow rate and consistent boric acid capture volume enable seamless interfacing with common autotitrators (e.g., Metrohm 809, Hanna HI84532) via standard borosilicate collection flasks.
What maintenance intervals are recommended for fluidic components?
Per manufacturer specifications, the internal tubing set requires replacement every 36 months under normal usage; reagent pump heads should be inspected quarterly and lubricated biannually.
Can the SKD-800 be validated for ISO/IEC 17025 accreditation?
Yes—the instrument’s deterministic process logic, comprehensive event logging, and configurable calibration checks support IQ/OQ/PQ documentation when paired with traceable reference materials (e.g., NIST SRM 84g casein).
Does the system support remote monitoring or network connectivity?
No native Ethernet or Wi-Fi capability is included; however, USB data export allows periodic synchronization with centralized laboratory databases.
What safety certifications does the SKD-800 hold?
It conforms to IEC 61010-1:2010 for electrical safety in laboratory equipment and carries CE marking for EMC and Low Voltage Directive compliance.