EXPEC Pre 4000 Atmospheric Pre-Concentrator with Stirling Cryocooler
| Brand | EXPEC |
|---|---|
| Origin | Zhejiang, China |
| Manufacturer Type | Authorized Distributor |
| Country of Origin | China |
| Model | Pre 4000 |
| Pricing | Available Upon Request |
Overview
The EXPEC Pre 4000 Atmospheric Pre-Concentrator is a fully automated, cryogen-free thermal pre-concentration system engineered for high-sensitivity analysis of trace-level volatile organic compounds (VOCs) in ambient air and other gaseous matrices. It employs a three-stage cryogenic trapping architecture coupled with a closed-cycle Stirling cryocooler—eliminating dependency on liquid nitrogen or liquefied CO₂ while achieving sustained cold trap temperatures down to –200 °C. This thermodynamic design enables reproducible analyte focusing across broad volatility ranges (C₂–C₁₂), supporting detection limits in the low-pptv (parts-per-trillion by volume) range when interfaced with gas chromatography–mass spectrometry (GC–MS) or GC–flame ionization detection (GC–FID). The instrument operates under controlled pressure and flow dynamics, adhering to fundamental principles of cryofocusing: adsorption at sub-ambient temperatures followed by rapid, narrow-band thermal desorption into the analytical column.
Key Features
- Stirling-based cryocooling: Zero consumables required; no liquid nitrogen logistics, dewar handling, or associated asphyxiation hazards.
- Three-stage cold trap configuration: Stage 1 (–30 °C) removes bulk water vapor without VOC loss; Stage 2 (–150 °C) uses selective sorbent packing to retain VOCs while rejecting CO₂, O₂, and N₂; Stage 3 (–200 °C) provides ultra-low-temperature focusing for highest-boiling analytes.
- Precision sampling module: Integrated mass flow controller (MFC) and diaphragm pump ensure accurate, temperature-invariant volumetric sampling from 10 mL to 10 L, compliant with EPA Method TO-15 and ISO 16017-1 requirements.
- Zero-dead-volume pulse desorption: Capillary-packed cold traps enable splitless, high-speed thermal desorption (<50 ms pulse width), minimizing band broadening and maximizing chromatographic resolution.
- Automated leak verification: System performs pressure-rise or vacuum-decay integrity checks across all fluidic pathways; results are logged with pass/fail status and timestamped audit trail.
- Dual-mode internal standard introduction: Supports both low-concentration standard gas injection via mass-flow-controlled valves and high-concentration standard delivery via fixed-volume quantitative loop—achieving ≤2% RSD for internal standard precision.
Sample Compatibility & Compliance
The Pre 4000 accommodates gaseous samples collected directly from ambient air, canister-based SUMMA®-type electropolished stainless-steel containers, and Tedlar® bags. It is compatible with common sorbent tubes (e.g., Tenax TA, Carbopack™ B/C, graphitized carbon black) used in passive and active sampling protocols. The system meets functional equivalency requirements outlined in U.S. EPA Methods TO-14A, TO-15, and ASTM D6196 for ambient VOC monitoring. Its firmware supports GLP-compliant operation with full electronic signature capability, 21 CFR Part 11–ready audit trails, and configurable user access levels. All pneumatic components comply with ISO 8573-1 Class 2 purity standards for instrument air supply.
Software & Data Management
Control and data acquisition are managed through EXPEC’s proprietary PreConc Control Suite v3.x—a Windows-based application with intuitive workflow-driven interface. The software enables method creation for multi-step concentration cycles (pre-conditioning, sampling, dry purge, focusing, desorption), real-time monitoring of trap temperatures, MFC setpoints, and system pressure, plus automatic calibration curve generation using internal standard response factors. Raw data files are stored in vendor-neutral .csv and .xml formats; integration with LIMS platforms is supported via OPC UA and ASTM E1384-compliant export modules. All method changes, user logins, and critical events (e.g., leak test failures, temperature excursions) are recorded in an immutable, time-stamped audit log meeting FDA and EU Annex 11 documentation expectations.
Applications
The Pre 4000 serves laboratories engaged in regulatory environmental monitoring (e.g., national air quality networks, industrial fence-line monitoring), emergency response screening for chemical release incidents, occupational exposure assessment per OSHA and NIOSH criteria, food packaging migration studies, indoor air quality investigations in public health settings, and academic research on atmospheric chemistry and VOC source apportionment. Its robustness and cryogen-free operation make it especially suitable for remote or mobile laboratory deployments—including vehicle-mounted air monitoring systems and field-deployable GC–MS laboratories.
FAQ
Does the Pre 4000 require liquid nitrogen or any cryogenic consumables?
No. It utilizes a maintenance-optimized Stirling cryocooler capable of reaching –200 °C without external cryogens.
Can the system be validated for regulated compliance testing?
Yes. It supports IQ/OQ protocols, includes factory calibration certificates traceable to NIST standards, and logs all operational parameters required for 21 CFR Part 11 and ISO/IEC 17025 accreditation.
What is the maximum recommended sampling volume for TO-15–compliant analysis?
Up to 10 liters at ambient conditions, adjustable via programmable MFC control with pressure and temperature compensation.
How is moisture interference managed without compromising polar VOC recovery?
Stage 1 cold trap operates at –30 °C—sufficient to condense >99.9% of H₂O while retaining methanol, acetaldehyde, and other highly volatile, water-soluble compounds.
Is remote diagnostics and firmware update supported?
Yes. Secure HTTPS-based remote access allows authorized service engineers to perform diagnostics, log review, and over-the-air firmware updates with version rollback capability.
