Chengmeng CM-24 Circular Water Bath Nitrogen Evaporator

Overview

The Chengmeng CM-24 Circular Water Bath Nitrogen Evaporator is an engineered solution for controlled, gentle solvent removal in analytical laboratories. It operates on the principle of inert gas-assisted surface evaporation—introducing a regulated stream of nitrogen (or compressed air) across the surface of heated liquid samples to accelerate solvent volatilization without thermal degradation. Unlike dry-block or infrared evaporators, the water bath design ensures uniform, low-gradient heating (ambient to 99 °C), minimizing thermal stress on thermolabile analytes such as pesticides, pharmaceuticals, hormones, and nucleic acid derivatives. The system is purpose-built for high-throughput sample preparation workflows requiring reproducible concentration prior to GC, HPLC, LC-MS, or ELISA analysis. Its circular architecture supports rotational alignment of sample racks and gas manifolds, reducing positional bias and enhancing inter-sample consistency.

Key Features

• 24-position circular sample platform with individually numbered positions and spring-loaded, adjustable tube clamps accommodating tubes from 10 mm to 29 mm in diameter (1–50 mL volume range)
• Independent vertical adjustment (200 mm travel) of stainless steel gas needles—each fitted with precision SMC TUS fluoropolymer-coated tubing (odorless, solvent-resistant) and a dedicated flow control valve
• Dual-gas capability: configurable for nitrogen (for oxidation-sensitive compounds) or compressed air (for robust matrices), with integrated pressure regulation (0.2 MPa max) and digital flow metering (0–15 L/min total, ~330 mL/min per channel)
• Stainless steel 304 water bath (Φ400 × 200 mm internal dimensions) with PID-controlled digital thermostat (66 × 45 mm LCD display), ±0.1 °C resolution, ≤0.5 °C temperature uniformity at 60 °C
• Full 360° synchronized rotation of both sample tray and gas manifold to prevent cross-contamination and ensure equidistant gas delivery
• Integrated safety functions: over-temperature alarm, dry-run protection, and thermal cutoff (250 V / 8 A fuse)
• Compact footprint (420 × 420 × 850 mm) optimized for fume hood integration; all wetted components chemically resistant to common organic solvents (e.g., acetonitrile, methanol, ethyl acetate, hexane)

Sample Compatibility & Compliance

The CM-24 accommodates standard laboratory vessels—including round-bottom test tubes, conical centrifuge tubes (15 mL and 50 mL), and small-volume vials—without adapter requirements. Its modular gas distribution system allows seamless transition between sample types while maintaining consistent evaporation kinetics. From a regulatory standpoint, the instrument supports GLP-compliant workflows when operated within documented SOPs: temperature logs can be manually recorded, and the PID controller provides stable setpoint retention required for method validation under ISO/IEC 17025 and USP . While the device itself is not FDA 21 CFR Part 11–certified (as it lacks electronic audit trail functionality), its mechanical repeatability and traceable temperature control make it suitable for pre-analytical steps in clinical, environmental, and food safety testing governed by ASTM D5887 (pesticide residue), EPA Method 525.3 (drinking water), and EN 15662 (multi-residue analysis).

Software & Data Management

The CM-24 operates via an embedded microprocessor-based controller with no external software dependency. All operational parameters—including target temperature, dwell time (0–9999 minutes), and real-time bath temperature—are displayed and adjusted locally via the front-panel LCD interface. No proprietary drivers, cloud connectivity, or data export protocols are implemented; this design prioritizes reliability, electromagnetic compatibility, and ease of qualification in regulated environments where IT validation overhead must be minimized. Users may integrate the unit into broader lab automation systems using simple dry-contact relay outputs (optional accessory) for start/stop signaling in sequence-controlled workflows.

Applications

• Agricultural residue analysis: Concentration of extracts from vegetables, fruits, cereals, and plant tissues prior to multi-residue pesticide screening (e.g., QuEChERS workflow)
• Pharmaceutical quality control: Solvent removal from herbal extracts, dissolution media, and stability study samples under GMP-aligned conditions
• Environmental monitoring: Pre-concentration of aqueous extracts from drinking water, groundwater, and wastewater for PAH, PCB, and organochlorine analysis
• Clinical and forensic toxicology: Gentle evaporation of biological fluids (serum, plasma, urine) prior to derivatization or immunoassay
• Food and beverage safety: Sample cleanup for dioxin, furan, and mycotoxin quantification in milk, alcoholic beverages, and liquid dietary supplements
• Commodity inspection: High-throughput preparation of samples for detection of adulterants (e.g., melamine, Sudan dyes) and contaminants (e.g., chloropropanols, glycidyl fatty acid esters)

FAQ

Is the CM-24 compatible with corrosive solvents such as hydrochloric acid or trifluoroacetic acid?
No. While the stainless steel bath and gas needles resist common organic solvents, prolonged exposure to strong mineral acids or halogenated corrosives is not recommended. Use only with solvents listed in the user manual’s chemical compatibility chart.

Can the instrument maintain temperature stability during extended overnight runs?
Yes. The PID algorithm and insulated bath design ensure ≤±0.5 °C deviation over 12+ hour cycles at setpoints up to 90 °C, provided ambient lab temperature remains stable and ventilation is adequate.

Does the system include a nitrogen generator or require an external gas supply?
The CM-24 requires an external nitrogen or compressed air source connected via standard 6 mm OD push-to-connect fittings. A dedicated nitrogen generator is not included but may be integrated upstream if required for purity-critical applications.

What maintenance is required to ensure long-term accuracy?
Routine cleaning of the water bath with deionized water and periodic inspection of O-rings and gas needle tips for clogging or wear. Calibration of the temperature sensor against a NIST-traceable reference thermometer is recommended annually or after any physical impact.

Is CE or UL certification available for this model?
The CM-24 complies with IEC 61010-1:2010 for electrical safety and EMC (EN 61326-1), and carries China Compulsory Certification (CCC). CE marking is not affixed, as the unit is configured for 220 V/50 Hz domestic supply; UL listing is not pursued due to absence of North American voltage variants.