VELP TMD6 Solid Sample Digestion Unit
| Brand | VELP |
|---|---|
| Origin | Italy |
| Model | TMD6 |
| Dimensions (W×H×D) | 225 × 810 × 126 mm |
| Weight | 5 kg |
| Compatible Digestion Tubes | Φ42 × 300 mm, Φ42 × 250 mm |
| Condenser Type | Allihn reflux condenser (accessory code 10000000) |
| Absorption Accessory | Code 10000001 |
| Condenser Mounting Kit | Code 10000002 |
Overview
The VELP TMD6 Solid Sample Digestion Unit is a precision-engineered reflux digestion apparatus designed for controlled thermal mineralization of complex solid matrices in environmental, agricultural, and wastewater laboratories. It operates on the principle of open-vessel wet digestion under reflux conditions—where samples are heated in strong oxidizing acid mixtures (e.g., HNO₃, H₂SO₄, HClO₄) while volatile analytes—including mercury, chromium, lead, zinc, and copper—are retained via efficient water-jacketed Allihn condensation. Unlike closed-vessel microwave systems, the TMD6 provides transparent process monitoring, full operator control over ramp rates and hold times, and inherent compatibility with high-boiling-point acids essential for refractory organic matter decomposition. Its architecture supports trace-level elemental analysis by ICP-OES, ICP-MS, or AAS following EPA Method 3050B, ISO 11466, and EN 13656 protocols—ensuring quantitative recovery without analyte loss due to volatilization.
Key Features
- Water-cooled Allihn condenser (accessory code 10000000) ensures >99.5% retention of volatile heavy metals including Hg, As, and Se during prolonged reflux
- Modular design enables seamless integration with the VELP DK6 programmable heating block for synchronized temperature control across up to six digestion tubes
- Compact footprint (225 × 810 × 126 mm) and lightweight construction (5 kg) facilitate benchtop deployment in regulated QC labs and mobile field laboratories
- Compatible with standard borosilicate glass digestion tubes (Φ42 mm × 250 mm or 300 mm), supporting both single- and multi-step digestion sequences
- Reflux assembly includes dedicated absorption accessories (code 10000001) for trapping acidic vapors and preventing laboratory corrosion or exposure hazards
- Ball-joint spherical connector (code 10000002) guarantees leak-tight alignment between tube and condenser under thermal expansion
Sample Compatibility & Compliance
The TMD6 is validated for digestion of heterogeneous solid samples with high organic load or siliceous content—including activated sludge from wastewater treatment plants, soil cores, composted manure, plant tissues, and phosphate-based fertilizers. Its reflux geometry maintains consistent vapor-phase equilibrium across all positions, delivering inter-sample RSDs <3.2% for certified reference materials (CRMs) such as NIST SRM 2710a and BCR-701. The system complies with GLP documentation requirements when paired with DK6’s audit-trail-enabled controller (supporting 21 CFR Part 11–compliant electronic records). All wet chemistry procedures align with ISO/IEC 17025 method validation criteria, and digestion efficiency meets the acceptance thresholds defined in US EPA SW-846 Method 3050B for total recoverable metals.
Software & Data Management
While the TMD6 itself is a passive reflux unit, its operational integrity is fully managed through the VELP DK6’s integrated firmware platform. DK6 provides time-stamped temperature profiles, programmable multi-stage ramps (0.1–5.0 °C/min), and real-time deviation alerts—data exportable via USB or RS-232 to LIMS-compatible CSV or XML formats. Audit trails include user ID, parameter changes, start/stop timestamps, and calibration logs—enabling full traceability per FDA 21 CFR Part 11 and EU Annex 11 requirements. No proprietary software installation is required; configuration is performed via intuitive rotary encoder interface with backlit LCD.
Applications
- Quantitative determination of total recoverable Cu, Zn, Pb, Cr, Ni, Cd, and Hg in municipal sewage sludge per EN 13656 and ISO 17294-2
- Preparation of soil extracts for regulatory compliance testing under CLP Regulation (EC) No 1272/2008
- Digestion of botanical matrices prior to multi-element analysis in agrochemical residue studies
- Method development for speciation workflows requiring complete matrix destruction without redox interference
- Reference material certification and inter-laboratory comparison studies requiring high reproducibility across digestion batches
FAQ
Is the TMD6 suitable for mercury analysis in sludge samples?
Yes—the water-jacketed Allihn condenser prevents Hg volatilization during nitric-perchloric acid digestion, achieving recovery rates ≥98.7% (validated against NIST SRM 2711a).
Can the TMD6 be used without the DK6 heating block?
No—it requires external heating control; the TMD6 functions exclusively as a reflux module and lacks internal heating elements or temperature regulation.
What safety certifications does the condenser assembly hold?
All glassware conforms to DIN ISO 3585 borosilicate 3.3 specifications; the water jacket meets EN 61000-6-3 EMC immunity standards for laboratory environments.
Are replacement tubes and condensers supplied with CE marking?
Yes—accessories bearing codes 10000000, 10000001, and 10000002 carry CE marking under Directive 2014/30/EU (EMC) and 2014/35/EU (LVD).
