Solvent removal is one of the most routine yet critical operations in any chemistry laboratory — and getting it wrong means lost samples, degraded compounds, and wasted hours. Whether your Singapore lab is synthesising new molecules at Biopolis, running quality-control assays at Tuas Biomedical Park, or teaching organic chemistry at NUS or NTU, a well-chosen rotary evaporator makes the difference between a smooth workflow and a bottleneck. This guide covers everything you need to know about rotary evaporators and how to select the right model for your work.
A rotary evaporator — often called a rotovap — operates on a straightforward principle: lower the pressure, lower the boiling point. The sample is placed in a round-bottom flask that rotates continuously in a heated water bath. Rotation does two things: it spreads the liquid into a thin film across the inner wall of the flask, dramatically increasing the surface area for evaporation, and it prevents bumping (sudden violent boiling) by keeping the liquid in motion.
Simultaneously, a vacuum pump or aspirator reduces the pressure inside the system. At reduced pressure, solvents boil at temperatures far below their atmospheric boiling points. For example, water boils at 40–50°C under moderate vacuum instead of 100°C. This means you can remove solvents quickly without exposing heat-sensitive compounds to damaging temperatures. The evaporated solvent travels through a vapour duct into a condenser — cooled by either tap water or a recirculating chiller — where it re-condenses into liquid and is collected in a receiving flask for disposal or recycling.
Modern benchtop rotary evaporators share a common architecture but vary significantly in capacity, automation, and temperature control. Below is a representative specification overview for the mid-range models available through JW RESEARCH SUPPLY in Singapore.
| Specification | RE-52AA (Economy) | RE-2000A (Standard) | RE-5000 (Advanced) |
|---|---|---|---|
| Evaporating Flask Capacity | 0.5 – 2 L | 1 – 3 L | 3 – 5 L |
| Collecting Flask Capacity | 1 L | 2 L | 3 L |
| Rotation Speed | 0 – 120 rpm | 20 – 200 rpm | 20 – 280 rpm |
| Heating Bath Temperature | RT – 99°C | RT – 99°C | RT – 180°C (±1°C) |
| Heating Power | 1.0 kW | 1.5 kW | 2.0 kW |
| Lift Mechanism | Manual | Manual / Motorised | Motorised (Auto-lift) |
| Condenser Type | Vertical | Vertical / Diagonal | Diagonal (Dual-coil) |
| Vacuum Range | < 10 mbar | < 5 mbar | < 2 mbar |
| Display | Analog | Digital (temp + rpm) | Full digital with programme memory |
| Bath Dimensions | Ø 220 × 120 mm | Ø 250 × 130 mm | Ø 280 × 150 mm |
| Power Supply | 220-240 V, 50/60 Hz | 220-240 V, 50/60 Hz | 220-240 V, 50/60 Hz |
| Typical Applications | Teaching, basic synthesis | R&D, QC, medium-throughput | High-throughput, pharma, CROs |
Match your evaporating flask capacity to your typical sample volume. Academic teaching labs often work with 500 mL to 1 L flasks, while pharmaceutical R&D and contract research organisations (CROs) in Singapore's Biopolis cluster routinely handle 2–5 L batches. For pilot-scale work, 10–20 L systems are available. Remember that the effective working volume is roughly 40–50% of the nominal flask capacity — overfilling leads to bumping and cross-contamination.
Manual-lift models like the RE-52AA are economical and reliable, perfectly adequate for teaching and low-throughput use. But for labs where multiple users run the instrument daily, a motorised lift (RE-2000A or RE-5000) pays for itself in convenience and reproducibility. Motorised lifts also support automatic flask-raising on power loss — a critical safety feature that prevents the flask from sitting in a hot bath when vacuum is lost.
If you work with thermally sensitive compounds — natural products, proteins, volatile flavour compounds — choose a model with digital temperature control offering ±1°C precision. Advanced models like the RE-5000 extend the heating range to 180°C, making them suitable for high-boiling-point solvents like DMSO or NMP, commonly used in pharmaceutical process development labs in Singapore.
Vertical condensers save bench space and work well for medium- to high-boiling-point solvents. Diagonal condensers, especially dual-coil types, provide a larger cooling surface and are preferred for low-boiling-point solvents like dichloromethane (b.p. 40°C) and diethyl ether (b.p. 35°C), where recovery efficiency matters. JW RESEARCH SUPPLY can configure your system with the optimal condenser based on your solvent portfolio.
A rotary evaporator is only as good as its vacuum source. We recommend pairing your rotovap with a chemical-resistant diaphragm pump and vacuum controller for precise pressure regulation. For labs without a central vacuum line, a compact standalone diaphragm pump is the practical choice — quiet, oil-free, and compatible with most organic solvents when used with a cold trap.
Rotary evaporators are ubiquitous in Singapore's life-sciences and chemical-research ecosystem:
A rotary evaporator is a precision instrument that repays routine care. Replace the vacuum grease on ground-glass joints every 2–3 months to maintain a proper seal. Inspect the PTFE sealing ring at the vapour-duct joint monthly — a worn ring is the most common cause of vacuum leaks. Keep the heating bath filled with distilled water (not tap water) to prevent scale build-up on the heating element. After evaporating corrosive solvents like acids or halogenated organics, flush the vapour duct and condenser with a suitable solvent and dry the system under vacuum. JW RESEARCH SUPPLY stocks all common consumables and spare parts for the models we supply in Singapore.
A rotary evaporator (rotovap) is used to gently remove solvents from samples by evaporation under reduced pressure. By rotating the sample flask in a heated water bath while applying vacuum, it increases the surface area for evaporation and lowers the boiling point, allowing efficient solvent removal without thermal degradation. Common applications include concentration of solutions, solvent recycling, distillation, and sample preparation in chemistry, pharmaceutical, and food science labs.
Rotary evaporators come in standard flask capacities ranging from 0.5L to 50L. For academic and small R&D labs in Singapore, a 1L–3L benchtop model is usually sufficient. Medium-scale pharmaceutical or contract-research labs typically require 5L–10L systems, while pilot-plant and production-scale operations benefit from 20L–50L industrial rotary evaporators. JW RESEARCH SUPPLY offers the full range and can advise on the right size based on your daily sample throughput.
Key features include: (1) motor lift vs. manual lift — motorised lifts improve reproducibility and ease of use; (2) rotation speed range — typically 20–280 rpm for versatile solvent evaporation; (3) temperature range of the heating bath — usually ambient +5°C to 180°C, with precision of ±1°C; (4) vacuum capability — compatible with diaphragm pumps or water-jet aspirators; (5) condenser type — vertical or diagonal, with optional cold-finger for low-boiling-point solvents; and (6) digital display and programmable settings for advanced workflow control.
Yes. JW RESEARCH SUPPLY provides full pre-delivery inspection, on-site installation, user training, and after-sales technical support across Singapore. Our service team covers all major lab clusters including Biopolis, Tuas Biomedical Park, Science Park, NUS, NTU, and A*STAR facilities. We also stock common consumables and spare parts locally for fast turnaround. Reach us at +65 8039 3660 or SINGAPORE@JWSHY.COM.