Separatory Funnels Singapore
Liquid-liquid extraction is one of the most frequent operations in chemistry, and the separatory funnel is the glassware that makes it routine. Pharmaceutical, analytical, environmental and teaching laboratories across Singapore use separatory funnels every day to partition compounds between immiscible solvent layers, wash reaction mixtures and isolate products.
At JW RESEARCH SUPPLY, we supply borosilicate separatory funnels in pear and cylindrical shapes, from 50 mL micro-scale sizes to 2000 mL preparative volumes, with PTFE stopcocks and interchangeable ground glass joints, to laboratories across Singapore. This guide covers shapes, sizes and stopcock options so you select the right funnel for your extraction work.
Separatory Funnel Specification Overview
| Shape | Capacity | Typical Joint | Best For |
|---|---|---|---|
| Pear-shaped | 50 – 2000 mL | NS 14/23 – 29/32 | Routine extraction, sharp layer separation |
| Cylindrical (graduated) | 250 – 2000 mL | NS 24/29 – 34/35 | Tall solvent layers, volume readings |
| Squibb-style | 125 – 2000 mL | NS 24/29 | Classic conical body, general use |
Stopcock and Joint Options Compared
| Feature | PTFE Stopcock | Glass Stopcock |
|---|---|---|
| Lubrication | None required | Stopcock grease needed |
| Solvent resistance | Excellent, broad range | Excellent, fully inert |
| Seizing / sticking | Rarely seizes | Can seize if unlubricated |
| Maintenance | Low — rinse and reuse | Higher — regrease regularly |
Key Features to Check When Ordering
- Glass quality — Choose borosilicate 3.3 glass for thermal and chemical resistance; it withstands repeated washing, autoclaving and contact with organic solvents without clouding or weakening.
- Stopcock type and bore — PTFE stopcocks with a 2 mm to 4 mm bore give precise flow control; larger bores drain viscous or dense layers faster. Confirm the stopcock is removable for cleaning.
- Ground glass joint — An interchangeable NS/ground joint lets you attach a stopper or connect the funnel to a flask; matched, well-ground joints seal without leaking when the stopper is seated.
- Graduations — For cylindrical funnels, permanent white enamel graduations help you read solvent volumes during repeated extractions; pear funnels are usually ungraduated.
- Stopper fit — The stopper should seat firmly with a slight twist. A loose or rocking stopper risks leaks and pressure loss during shaking.
Extraction Technique and Care Best Practices
Support the funnel in a ring on a retort stand and always keep both hands on the funnel during shaking — one holding the stopper in place and the other controlling the stopcock. Vent frequently by inverting the funnel with the stem raised and opening the stopcock away from your face and any other person. Let the layers settle completely, then drain the lower layer slowly through the stopcock and pour the upper layer out through the top. After use, rinse immediately with an appropriate solvent, wash with warm detergent solution, and rinse with deionised water; do not use abrasives that can scratch the glass and damage the ground surfaces.
Why Choose JWRESEARCH for Separatory Funnels in Singapore?
- Durable borosilicate glass — Heat- and chemical-resistant funnels built for daily extraction work.
- Complete size range — Pear, cylindrical and Squibb styles from 50 mL to 2000 mL.
- Reliable stopcocks — Smooth PTFE and precision glass stopcocks matched to each funnel.
- Fast local delivery — Quick dispatch across Singapore for routine restocking and urgent runs.
JWRESEARCH supplies separatory funnels and general laboratory glassware to pharmaceutical, analytical, environmental and teaching laboratories across Singapore. Contact us for sizes, stopcock options and volume pricing.
📞 +65 8039 3660 | ✉️ SINGAPORE@JWSHY.COM
🌐 www.jwresearch.cn
Frequently Asked Questions
Q: Pear-shaped or cylindrical separatory funnel — which should I choose?
Pear-shaped funnels are the everyday choice for most liquid-liquid extractions because their tapered body gives a sharper boundary between layers, which makes the interface easier to see and drain precisely. Cylindrical funnels hold a taller, thinner solvent layer and are preferred when you need maximum separation of closely related layers or larger volumes. For routine organic chemistry work, start with a pear-shaped funnel in 250 or 500 mL.
Q: What size separatory funnel do I need?
As a rule of thumb, choose a funnel with a total capacity of roughly twice the volume of liquid you plan to shake, because the funnel must never be more than half to two-thirds full during mixing. A 250 mL funnel comfortably handles extractions with 50 to 100 mL of aqueous phase plus solvent, while 500 mL and 1000 mL sizes suit preparative work and 2000 mL funnels are used for bulk separations. Keep small 50 and 125 mL funnels for micro-scale reactions and reagent-scale extractions.
Q: PTFE stopcock or glass stopcock — which is better?
PTFE (Teflon) stopcocks are the modern standard because they need no grease, turn smoothly even when wet, resist most solvents and never seize in the joint. Glass stopcocks with a ground-glass key require light stopcock grease and careful alignment, but suit applications where PTFE contamination or solvent swelling is a concern. For general Singapore laboratories, PTFE stopcocks offer lower maintenance and more reliable sealing.
Q: How do I avoid emulsions and safely vent a separatory funnel?
Vent regularly: after every two or three gentle inversions, hold the funnel with the stopper held firmly and the stem pointed away from everyone, then open the stopcock to release built-up vapour pressure. To reduce emulsions, shake gently rather than vigorously, add saturated salt solution to break stubborn emulsions, and allow sufficient standing time for the layers to settle fully before draining. Always remove the stopper or open it to atmosphere before draining the lower layer through the stopcock.