Jiayuan MD-12 Water Bath Nitrogen Evaporator

Overview

The Jiayuan MD-12 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: dry nitrogen gas is delivered via adjustable stainless-steel needles positioned just above the liquid meniscus of each sample tube, while simultaneous water bath heating maintains precise thermal energy input. This dual-mode approach—combining convective gas flow with conductive heat transfer—enables reproducible concentration of volatile organic solvents without thermal degradation of thermolabile analytes. Designed for routine use in regulated environments, the MD-12 supports method compliance with standard operating procedures aligned with AOAC, EPA Method 505/525/8081, and ISO 17025-accredited workflows. Its water bath architecture ensures superior temperature uniformity compared to dry-block alternatives, particularly critical when processing heterogeneous sample matrices such as pesticide extracts or biological fluids.

Key Features

• 12-position circular sample rack with engraved numeric indexing and spring-loaded, adjustable tube clamps accommodating tubes from Φ10 mm to Φ29 mm (1–50 mL volume range)
• Independently height-adjustable stainless-steel gas delivery needles (100 mm length) with precision needle-valve control per channel—enabling individual flow optimization and on/off actuation
• Digital PID-controlled water bath with ±0.1°C display resolution, ambient +5°C to 99°C setpoint range, and ≤±1°C temperature stability at setpoint
• Robust stainless-steel construction with solvent-resistant seals, transparent food-grade silicone gas tubing, and integrated dry-run protection with audible/visual alarm
• Full compatibility with fume hood integration: low-profile footprint (390×300 mm) and vertical needle alignment allow safe operation under negative pressure ventilation
• Ergonomic rotating sample platform for unobstructed access to all positions during tube loading/unloading and gas needle positioning
• Overtemperature cutoff and fuse-protected 1000 W heating system (250 V, 8 A, Ф5×20 mm)

Sample Compatibility & Compliance

The MD-12 accommodates a broad range of container formats—including round-bottom test tubes, conical centrifuge tubes, and small-volume vials—without adapter requirements. Its Φ10–29 mm tube diameter range and 200 mm vertical needle travel ensure optimal gas impingement geometry across varying solvent volumes and evaporation rates. All wetted materials meet USP Class VI biocompatibility standards and demonstrate full resistance to common extraction solvents (e.g., acetonitrile, ethyl acetate, hexane, dichloromethane). The instrument supports GLP/GMP-aligned documentation through traceable temperature logging (when paired with external data loggers), and its stable thermal profile satisfies calibration requirements outlined in ASTM E2077–22 (Standard Practice for Calibration of Laboratory Equipment). No firmware or software-based audit trails are embedded; however, manual calibration records and maintenance logs may be maintained per ISO/IEC 17025 Clause 6.4.10.

Software & Data Management

The MD-12 is a stand-alone analog-digital hybrid instrument with no onboard microprocessor, network interface, or proprietary software. Temperature control is managed via a dedicated PID controller with LED digital display; no drivers, USB connectivity, or cloud synchronization are provided. This architecture eliminates cybersecurity vulnerabilities and ensures long-term operational continuity without dependency on vendor software updates or licensing. Users retain full control over calibration frequency and documentation format—ideal for laboratories maintaining paper-based SOPs or integrating the unit into validated LIMS environments via external temperature dataloggers (e.g., Omega OM-DAQPRO-5300 or Testo 176 T4). While not compliant with FDA 21 CFR Part 11 out-of-the-box, the device can be qualified within a broader electronic record system when used with compliant third-party acquisition hardware and procedural controls.

Applications

• Residue Analysis: Concentration of pesticide extracts from QuEChERS-prepared fruit, vegetable, grain, and plant tissue homogenates prior to GC-MS or LC-MS/MS analysis
• Pharmaceutical Testing: Solvent removal from herbal extract fractions, dissolution media, and stability study samples under ICH Q5C conditions
• Environmental Monitoring: Pre-concentration of organochlorine compounds (e.g., PCBs, OCPs) from aqueous environmental samples per EPA Methods 8081B and 8270D
• Clinical & Forensic Toxicology: Preparation of plasma, serum, urine, and whole blood samples for quantitation of drugs of abuse, metabolites, and biomarkers
• Food Safety Screening: Final cleanup step in dioxin/furan (PCDD/F) and polycyclic aromatic hydrocarbon (PAH) analysis workflows
• Research Chemistry: Parallel synthesis workups, combinatorial library purification, and small-molecule derivatization where solvent exchange or volume reduction is required

FAQ

What is the maximum recommended operating temperature for continuous use?
The MD-12 is rated for sustained operation up to 99°C; however, prolonged use above 85°C may accelerate evaporation of the water bath medium and increase thermal stress on silicone tubing—routine top-up and visual inspection are advised.
Can the instrument be used with gases other than nitrogen?
Yes—argon or compressed air may be substituted depending on analyte stability and safety requirements; however, oxygen-containing gases are not recommended for oxidation-prone compounds.
Is calibration certificate included with shipment?
No factory-issued calibration certificate is supplied; users must perform initial verification using NIST-traceable thermometers and certified flow meters per their internal quality protocol.
How often should the silicone tubing be replaced?
Under typical usage (≤8 hrs/day, non-aggressive solvents), replacement every 6–12 months is recommended; more frequent change is required when handling chlorinated or highly aromatic solvents.
Does the unit support external temperature probe input for independent validation?
No—the MD-12 lacks auxiliary sensor ports; validation requires insertion of a calibrated probe directly into the water bath alongside the built-in sensor.