Gerhardt Vapodest 450 Automated Kjeldahl Distillation Unit
| Brand | Gerhardt |
|---|---|
| Origin | Germany |
| Model | Vapodest 450 |
| Instrument Type | Kjeldahl Nitrogen Determinator |
| Nitrogen Detection Range | ≥0.1 mg N |
| Distillation Time | 3.5 min per sample |
| Repeatability | ≤±1% RSD |
| Sample Weight Capacity | ≤5 g (solid) / ≤20 mL (liquid) |
| Nitrogen Recovery Rate | >99.5% |
| Power Consumption | 2200 W |
| Dimensions (L×W×H) | 527 × 390 × 697 mm |
Overview
The Gerhardt Vapodest 450 is a fully automated, microprocessor-controlled steam distillation unit engineered for high-precision Kjeldahl nitrogen determination in compliance with ISO 8968, AOAC 981.10, AOAC 984.13, and ASTM D1127–16 standards. It operates on the principle of controlled steam distillation: after acid digestion, alkaline hydrolysis liberates ammonium ions as volatile ammonia, which is quantitatively swept from the digested sample by precisely regulated steam into an acidic boric acid receiver solution. The Vapodest 450 integrates real-time steam pressure modulation (10–100% programmable), automatic reagent dosing, and integrated process monitoring to ensure stoichiometric completeness and minimal analytical drift—critical for regulatory-grade protein quantification in food, feed, pharmaceutical, and environmental laboratories.
Key Features
- Fully programmable distillation sequence: automatic water dilution, NaOH addition, receiving solution dosing, timed distillation, post-distillation delay, steam flow optimization, and waste tube evacuation
- Intelligent steam generator with standby mode, overheat protection, and adjustable steam output (70% ideal for alcohol distillation per AOAC 920.157)
- Corrosion-resistant polymer housing and interchangeable glass/plastic distillation heads for method flexibility (e.g., volatile acids, formaldehyde, SO₂, phenols, sulfides)
- Large backlit LCD interface displaying real-time step progression, error codes (e.g., low coolant, pump failure, pH sensor timeout), and audible/visual alerts
- Modular architecture supporting external titration systems (e.g., Metrohm 809/856 Titrando) and optional pH electrode integration for endpoint detection
- Pre-stored method library with user-definable programs; firmware compliant with EN ISO 9001:2000 throughout design, manufacturing, and final QA testing
Sample Compatibility & Compliance
The Vapodest 450 accommodates standard Kjeldahl digestion vessels—including 250 mL, 400 mL, and 800 mL digestion tubes, and wide-neck flasks (250/500/750 mL)—enabling seamless workflow integration with Gerhardt KB, CSB, and SMA digestion systems. Its validated recovery (>99.5%) and repeatability (≤±1% RSD) meet GLP/GMP requirements for routine QC in accredited labs. The system supports analysis across diverse matrices: cereals, dairy products, meat, beverages, soil extracts, wastewater, pharmaceutical intermediates, and chemical reagents. All operational parameters—including steam ramp profiles, alkali volume, and distillation duration—are traceable and auditable, satisfying FDA 21 CFR Part 11 data integrity expectations when paired with compliant LIMS or titration software.
Software & Data Management
Control firmware features non-volatile memory for ≥20 user-defined methods, each with independent setpoints for steam intensity, base volume, dilution water volume, receiver volume, distillation time, and cooling delay. Process logs record timestamped events (start/stop, reagent dispense confirmation, steam pressure deviation >±5 kPa, coolant flow interruption). Optional RS-232/USB connectivity enables direct export of raw distillation metadata (e.g., sample ID, method ID, start time, end time, total steam volume consumed) to laboratory information management systems. No proprietary cloud platform is required; data remain under full institutional control.
Applications
Beyond primary Kjeldahl nitrogen and crude protein quantification (N × 6.25 or matrix-specific factors), the Vapodest 450 executes standardized steam distillation protocols for: volatile basic nitrogen (VBN) in fish spoilage assessment (ISO 6496); ammoniacal nitrogen in wastewater (ISO 5664); formol titration for casein in milk (ISO 8968-2); total volatile acidity in wine (AOAC 920.124); free formaldehyde in resins (ISO 14184-1); phenolic compounds (ISO 6439); sulfur dioxide in fruit juices (AOAC 990.28); and hydrazine in boiler water (ASTM D129–16). Its precise 70% steam setting is optimized for ethanol recovery in alcohol content determination per AOAC 920.157 and OIV-MA-AS313.
FAQ
What digestion systems are compatible with the Vapodest 450?
The unit is mechanically and chemically designed for direct coupling with Gerhardt KB, CSB, and SMA series digesters, though standard Kjeldahl tubes (250–800 mL) and wide-neck flasks (250/500/750 mL) from third-party manufacturers may also be used.
Does the Vapodest 450 support unattended overnight operation?
Yes—its robust thermal management, auto-shutdown on coolant loss, and fault-tolerant pump sequencing allow extended batch runs; however, operator verification of reagent levels and waste container capacity is recommended prior to unattended use.
Is calibration required before first use?
No factory calibration is needed—the system performs self-diagnostics at power-on; users validate performance using certified nitrogen reference materials (e.g., glutamic acid, ammonium sulfate) per ISO 5725-2 precision protocols.
Can the Vapodest 450 be integrated into a fully automated Kjeldahl workflow?
Yes—it accepts TTL-level trigger signals from compatible digestion units and outputs status signals to external titrators, enabling end-to-end automation without manual intervention between digestion and titration steps.
