MICHEM FS-II Infrared Heating Digestion System for Feed Sample Preparation
| Brand | MICHEM |
|---|---|
| Model | FS-II |
| Type | Infrared Heating Digestion System |
| Heating Block | PTFE-Coated High-Purity Graphite |
| Max Power | 3000 W |
| Control System | PID Digital Temperature Controller |
| Temperature Range | Up to 260 °C |
| Temp. Accuracy | ±0.2 °C |
| Programmable Steps | 30 |
| Sample Capacity | 8 × 100 mL Vessels |
| Pressure Rating (Digestion Vessels) | 10 MPa |
| Dimensions (W×D×H) | 670 × 460 × 270 mm |
| Input Voltage | AC 220 V / 50 Hz, 16 A |
| Compliance | Meets GB/T 150 (China National Standard for Pressure Vessels) |
Overview
The MICHEM FS-II Infrared Heating Digestion System is a purpose-engineered thermal digestion platform designed specifically for the quantitative preparation of feed and animal nutrition samples prior to elemental analysis. Unlike conventional muffle furnace ashing—which risks volatilization loss of trace elements such as selenium, iodine, mercury, and arsenic—or microwave-assisted digestion systems requiring complex safety protocols and high operational overhead, the FS-II employs infrared radiation coupled with high-thermal-mass graphite heating blocks to deliver uniform, controllable, and reproducible conductive heating. Its core function is closed-vessel acid digestion under elevated temperature and pressure, enabling complete mineralization of complex organic matrices (e.g., soybean meal, fishmeal, premixes, silage) using HNO₃, H₂O₂, or HCl-based reagents. This ensures full recovery of analytes for downstream quantification by ICP-OES, ICP-MS, AAS, or ICP-AES—critical for compliance with AOAC Official Method 985.27, ISO 6497, and GB/T 13885.
Key Features
- High-purity graphite heating block with electrophoretically applied PTFE coating—resistant to concentrated HNO₃, HCl, HF (with appropriate vessel selection), and aqua regia; surface hardness >9H, minimizing scratching and cross-contamination.
- PID digital temperature controller with 30-segment programmable ramp-hold profiles; supports gradient heating (e.g., 10 °C/min to 120 °C, hold 15 min; then 5 °C/min to 220 °C, hold 30 min) to prevent violent boiling or splashing.
- Dual-layer, reinforced PEEK-fiberglass composite digestion vessels rated to 10 MPa burst pressure and certified per GB/T 150.1–2011 (Chinese Pressure Vessel Code); includes pressure-relief safety valves and real-time pressure monitoring ports (optional).
- Integrated infrared emitter array beneath the graphite block ensures rapid thermal response (<60 s to reach setpoint from ambient) and minimal thermal lag across all 8 positions—inter-position temperature variation ≤±0.5 °C at 220 °C.
- Front-panel LCD with English-language interface, password-protected method storage (up to 50 user-defined programs), and hardware interlock preventing lid opening during active digestion cycles.
Sample Compatibility & Compliance
The FS-II accommodates standard 100 mL high-pressure digestion tubes compatible with common feed sample masses (0.2–1.0 g dry weight). It supports digestion of pelleted, extruded, powdered, and liquid feed formulations—including those containing high-fat (>12%) or high-fiber (>18%) content—without pre-dilution or charring. All wet digestion protocols developed on this system are validated against reference materials NIST SRM 1577c (Bovine Liver) and ERM-BB184 (Animal Muscle). The instrument’s mechanical design complies with IEC 61010-1:2010 for laboratory electrical equipment safety; digestion vessels meet ASME BPVC Section VIII Div. 1 requirements when used within specified temperature/pressure limits. Full traceability logs (time-stamped temp/pressure events) support GLP and GMP audit readiness.
Software & Data Management
While the FS-II operates via standalone front-panel control, optional RS-232/USB interface enables connection to LIMS or custom SCADA environments. Logged data—including actual vs. setpoint temperature curves, dwell times, and error codes (e.g., “Overtemp Alarm”, “Open Lid Detected”)—are exportable in CSV format. Firmware version 2.4+ supports 21 CFR Part 11–compliant electronic signatures when paired with validated third-party software (e.g., LabArchives or Thermo Fisher SampleManager). Audit trails record operator ID, method name, start/stop timestamps, and any parameter modifications—retained for ≥36 months per internal SOP.
Applications
- Quantitative determination of Ca, P, Cu, Zn, Fe, Mn, Co, I, Se in compound feeds per GB/T 18868 and EU Regulation (EC) No 1831/2003.
- Method validation for heavy metal screening (Pb, Cd, As, Hg) in pet food raw materials aligned with FDA CPG 7106.04 and EC No 1881/2006.
- Preparation of digestates for enzymatic activity assays (e.g., phytase, amylase) where residual oxidant interference must be minimized.
- Routine QC testing in feed mills and contract laboratories accredited to ISO/IEC 17025:2017.
FAQ
Can the FS-II be used for environmental soil or sludge samples?
Yes—provided digestion vessels are rated for the required acid strength and temperature profile; however, feed-specific validation data does not automatically extend to EPA Method 3050B or 3051A without re-qualification.
Is HF acid compatible with the PTFE-coated graphite block?
No—HF etches graphite and degrades PTFE. Use quartz or PFA vessels with external HF-resistant heating mantles for hydrofluoric acid applications.
What maintenance is required for long-term temperature stability?
Annual recalibration of the embedded Pt100 sensor against a NIST-traceable reference thermometer is recommended; graphite block surface inspection for coating integrity every 500 cycles.
Does the system include digestion vessels and caps?
Vessels are supplied as optional accessories—standard configuration includes only the main unit, controller, and 8-position graphite block.
How is overpressure managed during exothermic reactions?
Each vessel incorporates a dual-stage pressure release mechanism: primary rupture disk (10 MPa) and secondary spring-loaded valve (8.5 MPa), both independently certified and replaceable per batch.
