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Sylvia Rose

Separatory Funnel: Alchemy Lab Equipment

A separatory funnel is an essential piece of laboratory equipment used in liquid-liquid extractions, allowing alchemists to separate components of mixtures effectively. Alchemy begins in Alexandria, Egypt, a glass manufacturing center, in the early decades AD.



Separatory Funnel
Separatory Funnel

What is a Separatory Funnel and How Does it Work?


A separatory funnel is a conical piece of glassware with a stopcock at the bottom. It’s designed to separate immiscible liquids of different densities, commonly to separate organic solvents from water or other liquid layers. It can be used in production of essential oils.


The operation is straightforward:


  1. The alchemist pours the mix of liquids into the funnel.

  2. When the funnel is inverted, denser liquid begins to settle at the bottom.

  3. After allowing the mixture to rest, the alchemist opens the stopcock to drain the denser liquid into a receiving container.

  4. The less dense liquid stays in the funnel, allowing for fairly accurate separation.



Two Separatory Funnels
Two Separatory Funnels

Often conical, the design of the separatory funnel varies. It can be tubular, egg-shaped, pear-shaped or custom designed. It can be as simple as a rolled up leaf tied at the bottom or as complex as a multi-armed transparent beast. Most importantly it gets the job done.


Historical Origin of the Separatory Funnel


Although the exact date of its invention remains unclear, the separatory funnel is a fundamental piece and evolves along with other glassware in laboratories. The first separatory funnel is a hand-made conical device with a stopper at one end.



fanciful funnel of fluids

The basic, practical design is as ancient as human history. Alchemists from the early years AD use rudimentary utensils like the separatory funnel for such processes as distillation and separation.


Many inventions go back to Alexandrian practitioners like Maria the Jewess, who praises the marvels of glass laboratory equipment and invents several apparatuses; or Cleopatra the Alchemist, who's credited with invention of the alembic.



Alembic for Simple Distillation
Alembic with collection vessel for Simple Distillation

Alexandria is a center for medical learning in the later years BCE, thus glassware is already being designed to withstand chemical interactions and heat. Some ancient glassware has survived thousands of years.


The separatory funnel emerges in alchemical writings of the Renaissance but most likely has its prototypical beginnings in Alexandria, eventually to evolve in flask and stopcock design. It revolutionizes chemistry by facilitating extraction and purification of compounds.



Parts of a Separatory Funnel
Parts of a Separatory Funnel

Composition and Production of Separatory Funnel


Typically made of glass, separatory funnels today are tougher than the early equipment made by Alexandrian glassmakers. The modern introduction of Pyrex for high-heat jobs results in less breakage.


Pyrex or borosilicate glass is the most widely used form of glass today. It's resistant to thermal shock and chemical corrosion. Production methods involve precision molding or blowing to create a seamless body with a uniform thickness.



Tubular Separatory Funnel
Tubular Separatory Funnel

The stopcock mechanism is often crafted from the same robust glass and/or polyvinyl chloride (PVC). Some modern versions are also produced in plastics like polypropylene, a cost-effective and lightweight option.


What Can be Done with a Separatory Funnel?


Separatory funnels are versatile laboratory tools, used mainly for:


  • Liquid-Liquid Extraction: Separating components based on their solubility in different solvents.

  • Purification Processes: Helping to isolate and purify compounds in organic chemistry.

  • Analytical Techniques: Assisting in the preparation of samples for further analysis.

  • Emulsion Breaking: Breaking emulsions by separating layers, especially in processes involving oils and aqueous solutions.



funnel art
Funnel Art

They're also popular in pharmacology, petrochemical refining, and food science, organic chemistry, biochemistry and research. Apart from isolating compounds, separatory funnels help extract impurities, do chemical reactions, and are used in production of certain drugs.


Other Names for Separatory Funnel


  • Separating Funnel

  • Separation Flask

  • Extraction Funnel



a closer look at stopcocks
a closer look at stopcocks

Facts About Separatory Funnels


  1. Capacity Variations: Separatory funnels come in various sizes, typically ranging from 50 ml to 3 liters for different laboratory needs.

  2. Safety Guidelines: avoid overfilling the funnel, as it may lead to spills when inverted.

  3. Usage Technique: Gentle swirling while holding the stopper promotes interaction between immiscible layers without emulsifying them.

  4. Calibration Markings: Many funnels include volume markings for better accuracy in liquid transfers.

  5. The stopcock on a separatory funnel allows for precise control over the release of liquids, ensuring accurate separations.

  6. In design, some separatory funnels include a stopper with an additional tube for dispensing of liquids.

  7. The capacity of separatory funnels can vary, with sizes ranging from small-scale laboratory use to industrial-scale applications.



glass lab equipment
Lab Equipment

Non-Fiction Books:


Fiction Books:

READ: Lora Ley Adventures - Germanic Mythology Fiction Series

READ: Reiker For Hire - Victorian Detective Murder Mysteries




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