Zhuhui JX-6AT Fully Automated Two-Stage Thermal Desorber
| Brand | Zhuhui |
|---|---|
| Origin | Beijing, China |
| Manufacturer Type | Direct Manufacturer |
| Instrument Type | Two-Stage Thermal Desorber / Cold-Trap Thermal Desorber |
| Automation Level | Fully Automated |
| Primary Desorption Temperature Range | 40–400 °C |
| Secondary Desorption Temperature Range | −35–450 °C |
| Valve Heating Range | 40–240 °C, Accuracy: ±1 °C |
| Transfer Line Temperature Range | 40–240 °C, Accuracy: ±1 °C |
| Cold Trap Temperature Range | −35 to −5 °C |
| Temperature Control Accuracy | ±1 °C |
| Sample Positions | 40 |
| Cold Trap Cooling Method | Semiconductor-based |
| Secondary Desorption Ramp Rate | >70 °C/s |
| Peak Width (at 450 °C) | <3 s |
| Sample Tube Dimensions | 1/4″ OD × 3.5″ L |
| Enrichment Time | 0–60 min |
| Injection Time | 0–10 min |
| Simulated Sampling Time | 0–60 min |
| Simulated Flow Rate | 0–200 mL/min |
| RSD | ≤2.5% (benzene in 0.05 μg methanol) |
| Max Power Consumption | 500 W |
| Gas Path Materials | Passivated 316 stainless steel (RESTEK Siltek®/Sulfinert®-treated), PTFE seals, heated valve oven & transfer lines integrated |
| Compliance | GB 50325-2020, GB/T 18883-2022, HJ 583-2010, HJ 644-2013, HJ 734-2014 |
Overview
The Zhuhui JX-6AT Fully Automated Two-Stage Thermal Desorber is an engineered solution for high-fidelity thermal desorption of volatile and semi-volatile organic compounds (VOCs and SVOCs) from sorbent tubes prior to GC or GC-MS analysis. It implements a two-stage desorption process: primary thermal desorption releases analytes from the sorbent matrix into a cryogenically focused cold trap; secondary rapid thermal desorption then injects the concentrated analyte band—sharpened by ultra-fast heating (>70 °C/s)—directly into the gas chromatograph. This architecture minimizes band broadening, maximizes sensitivity, and ensures reproducible quantitation across complex environmental matrices. Designed for unattended operation in regulated laboratories, the JX-6AT supports full method compliance with major Chinese environmental standards—including GB 50325-2020 (indoor air benzene and TVOC), GB/T 18883-2022, and HJ-series methods for ambient air, indoor air, and stationary source emissions.
Key Features
- Fully automated 40-position carousel enables overnight batch processing without operator intervention; integrates native start/stop signaling with GC systems via TTL or contact closure.
- Semiconductor-based cold trap achieves stable temperatures from −35 °C to −5 °C—eliminating reliance on liquid nitrogen or mechanical chillers, reducing operational cost and infrastructure requirements.
- Motor-driven valve actuation with pneumatic tube handling ensures precise, repeatable adsorbent tube loading/unloading; proprietary cap-removal mechanism accommodates standard 1/4″ OD × 3.5″ sorbent tubes without consumable adapters.
- Heated valve oven and transfer line are co-engineered as a single thermal zone (40–240 °C, ±1 °C), minimizing dead volume through optimized tapered fittings and eliminating condensation-related carryover.
- Gas path constructed entirely from RESTEK Siltek®/Sulfinert®-passivated 316 stainless steel tubing and PTFE seals—validated for inertness up to 450 °C and compliant with low-bleed requirements for trace-level VOC analysis.
- Onboard diagnostic logic monitors motor position, pressure integrity, and thermal stability; triggers automatic shutdown and fault logging upon detection of mechanical deviation or seal leakage.
- Integrated simulated sampling module allows programmable flow rates (0–200 mL/min) and durations (0–60 min), enabling calibration verification and system suitability testing per HJ 644-2013 and USP .
Sample Compatibility & Compliance
The JX-6AT accepts industry-standard 1/4″ OD stainless steel or glass sorbent tubes packed with multi-bed media (e.g., Tenax TA, Carbopack B/C, Carboxen 1000). Its temperature-controlled desorption zones accommodate diverse sorbent chemistries and analyte volatilities—from C2 hydrocarbons to C18 PAHs. The instrument meets functional requirements for method validation under GLP and ISO/IEC 17025 frameworks. Its software architecture supports audit-trail generation and user-access controls aligned with FDA 21 CFR Part 11 principles. All thermal parameters—including ramp rate, hold times, and cooling profiles—are fully programmable and stored with timestamped metadata, facilitating traceability during regulatory inspections per GB 50325-2020 Annex E and HJ 734-2014 Section 7.3.
Software & Data Management
Controlled via a dedicated Windows-based application, the JX-6AT software provides method editor, sequence scheduler, real-time status dashboard, and event-log viewer. Each run records complete thermal profiles (primary/secondary desorption, cold trap, valve, and line temperatures), pressure traces, and timing events. Export formats include CSV and XML for LIMS integration. Method templates conform to HJ 583-2010 and HJ 644-2013 procedural sequences—including pre-desorption bake-out, inert gas purge, cryofocusing, and ballistic injection. Audit trails capture user ID, parameter changes, and system alerts with immutable timestamps—supporting data integrity requirements for accredited environmental testing laboratories.
Applications
- Indoor air quality monitoring: Quantification of benzene, toluene, ethylbenzene, xylenes (BTEX), and TVOC per GB 50325-2020 and GB/T 18883-2022.
- Ambient air analysis: Speciated VOC measurement in urban, industrial, and background sites using HJ 583-2010 and HJ 644-2013 protocols.
- Stationary source emission testing: VOC profiling from stack gases per HJ 734-2014, including aldehydes, ketones, and chlorinated solvents.
- Material emission screening: Testing of carpets, adhesives, paints, and composite building materials for formaldehyde and other off-gassing compounds.
- Method development and validation: Optimization of desorption parameters, breakthrough volume assessment, and sorbent comparison studies under controlled flow and temperature conditions.
FAQ
What sorbent tube formats does the JX-6AT support?
The instrument is configured for standard 1/4″ OD × 3.5″ stainless steel or glass sorbent tubes. No adapter kits or custom hardware are required.
Does the JX-6AT comply with international regulatory standards such as EPA TO-17?
While designed to meet Chinese national standards (GB, HJ), its performance specifications—including cold trap temperature stability, secondary desorption ramp rate (>70 °C/s), and RSD ≤2.5%—align with core technical requirements of EPA TO-17 and ISO 21047 for thermal desorption-GC analysis.
How is system leak integrity verified?
The built-in diagnostics include automated pressure hold tests at multiple points in the gas path. A dedicated maintenance mode enables stepwise isolation of valve, cold trap, and transfer line segments for targeted leak detection using electronic sniffer or pressure decay methods.
Can the JX-6AT be integrated into an existing LIMS environment?
Yes—raw data files (CSV/XML) and audit logs are structured for direct ingestion into common LIMS platforms. Custom API extensions are available upon request for bidirectional instrument-LIMS communication.
What maintenance intervals are recommended for long-term reliability?
Routine checks include quarterly verification of cold trap minimum temperature, biannual calibration of temperature sensors against NIST-traceable references, and annual replacement of PTFE seals and sorbent tube o-rings—documented in the included maintenance log template.
