Specifications

Component List

All components listed below are included in this kit. Items marked Optional can be customized.

Available Joint Sizes · GB/ISO/ASTM Standards

All sizes share 1:10 standard taper — GB, ISO, and ASTM sizes are interchangeable

14/19 19/26 24/29 (GB·recommended) 29/32 34/35 · 45/40 · 50/42 custom

GB (Chinese) 14/19 · 19/26 · 24/29 · 29/32 ISO 14/19 · 19/26 · 24/29 · 29/32 ASTM (American) 14/20 · 19/22 · 24/40 · 29/42

* All components have matching joint sizes for full system compatibility. ASTM and GB/ISO sizes share 1:10 taper — seal lengths differ but are interchangeable.

Component	Standard Spec	Available Joint Sizes	Upgrade Options	Qty	Link
Please contact us to confirm the available specifications.

📌 Customization Notes:
• Joint size can be selected to match your existing lab system:
GB (Chinese): 14/19 · 19/26 · 24/29 · 29/32
ISO: 14/19 · 19/26 · 24/29 · 29/32
ASTM (American): 14/20 · 19/22 · 24/40 · 29/42
• Extractor capacity: 250ml (standard), 500ml
• Solvent type: Light-solvent (standard), Heavy-solvent
• Flask capacity matched to extractor size
• Mix and match — no minimum order quantity
• Special requirements? Just ask our technical team

💡 Recommended Add-Ons: Boiling stones/anti-bumping granules · Separatory funnel stand · Erlenmeyer flasks · Thermometer

Product Description

I. How Continuous Extraction Works

Continuous extraction (also called continuous liquid-liquid extraction) works on the same principle as Soxhlet extraction, but Soxhlet extracts solids — continuous extraction extracts liquids.

The cycle has four steps:

Evaporation — Solvent in the boiling flask is heated to vapor
Condensation — Vapor condenses in the condenser and drips into the extractor containing the sample solution
Contact & Extraction — Solvent passes through the aqueous sample (rising if lighter, sinking if heavier), contacting the target compound
Siphon Drain — When the liquid level reaches the siphon tube top, the solvent containing extracted target returns to the flask — completing one cycle

The cycle repeats automatically for hours — equivalent to dozens of manual extractions.

✦ Continuous vs Manual Separatory Funnel Extraction:

Manual Extraction: Shake, separate, drain, repeat — tedious but fine for routine samples.
Continuous Extraction: Solvent cycles automatically — unattended, higher efficiency, especially for low partition coefficient samples.
Key difference: Manual relies on repeated operator effort; continuous relies on automated cycling.

II. What's in the Setup

Continuous Extractor — Core component; one-piece glass tube with sample chamber and siphon tube
Round-Bottom Flask — Holds extraction solvent, collects extracted material
Spherical Condenser — Condenses solvent vapor
Separatory Funnel — For solvent/water separation after extraction
Heating Mantle (or Water Bath) — Heats the solvent
Iron Stand & Universal Clamps — Secures the apparatus

III. Light vs Heavy Solvent Extractors

Continuous extractors come in two configurations based on solvent density:

Light-Solvent Type (solvent lighter than water, e.g., ether, ethyl acetate) — condensate enters from the top, rises through the aqueous phase, siphon drains from the bottom
Heavy-Solvent Type (solvent heavier than water, e.g., dichloromethane, chloroform) — condensate enters from the bottom, sinks through the aqueous phase, siphon drains from the top

Light solvent requires a light-solvent extractor; heavy solvent requires a heavy-solvent extractor. They are not interchangeable.

IV. Material & Workmanship

The continuous extractor is blow-molded from borosilicate glass 3.3 — one-piece construction with no seams. The siphon tube and sample chamber are precisely positioned for reliable siphon action. All ground joints are standard taper for tight connections with the flask and condenser.

Applications

Typical Applications

Trace Organic Enrichment

Pesticide residues, PAHs, PCBs from water samples

Natural Product Isolation

Continuous extraction of active compounds from plant aqueous extracts

Drug Residue Analysis

Antibiotics, hormone residues from food of animal origin

Environmental Monitoring

Organic pollutants from surface and groundwater

Low Partition Coefficient Samples

Compounds with single-extraction recovery below 50% — continuous extraction dramatically improves recovery

Suitable Conditions

Target compound has a low partition coefficient (requires multiple extractions for recovery)
Sample volume is large (100ml+ aqueous samples)
Solvent boiling point is moderate (40–100℃)
Not suitable for micro samples — use liquid-liquid extraction with a separatory funnel instead

Target Type	Recommended Solvent	Solvent Density	Typical Time
Please contact us to confirm the available specifications.

Operation & Maintenance

User Guide

Continuous extraction runs for extended periods — the setup and monitoring steps are more involved than manual extraction.

I. Before You Start

Confirm your extractor type matches your solvent — light-solvent or heavy-solvent
Check all glassware for cracks — cracked glass is unsafe
Check the siphon tube for blockages — new ones are fine, but used ones need checking
Make sure cooling water is available for the condenser

Assembly sequence

Add extraction solvent and boiling stones to the flask, place in the heating mantle
Mount the continuous extractor on the flask — the lower tube must be immersed below the liquid surface in the flask (for light-solvent type)
Add the sample solution through the extractor top (or side port) — liquid level below the siphon tube top
Mount the spherical condenser on the extractor top
Secure the flask, extractor, and condenser with clamps — ensure the apparatus is vertical
The condenser top must remain open (vented to atmosphere)

III. Cooling Water & Heating

Turn on cooling water first — bottom-in, top-out
Start heating — slowly bring the solvent to steady reflux
Watch for continuous small bubbles rising through the extractor — that means extraction is working

IV. Monitoring

Continuous extraction typically runs 4–16 hours — check every 30–60 minutes
Three things to watch: ① Reflux is steady; ② Bubbles are present in the extractor; ③ Flask liquid level is normal
If the siphon frequency drops noticeably — check solvent level and siphon tube for blockages

V. Shutdown

Turn off the heating mantle first — allow the apparatus to cool naturally
Keep cooling water running during cooling
When the flask reaches room temperature, turn off the cooling water
Disassemble in reverse order
Transfer the extract from the flask to a separatory funnel, separate solvent and aqueous phases
The organic phase is ready for concentration or analysis

📌 Light-solvent extractor installation — critical detail:

The lower tube of a light-solvent extractor must be submerged below the liquid level in the boiling flask. This allows vapor to enter the extractor through the lower tube, bubble up through the sample solution, and complete the extraction. If the lower tube isn't submerged, the solvent only circulates between the flask and extractor — the sample never gets extracted.

💡 From a Seasoned Lab Hand:

"Continuous extraction has two main enemies — dry heating and suck-back." Both happen when you're not paying attention.
How to prevent suck-back? When shutting down, remove the stopper from the condenser top first (or open a vent) before turning off the heat — let the system return to atmosphere.
Solvent running low? Solvent evaporates during operation — if the flask level drops significantly, add solvent through the condenser top (cool first, then add).
How long is enough? Count siphon cycles — 20～30 cycles usually extracts most of the target compound.

Care & Notes

Show care & notes

⚠️ Safety & Compliance Checklist

Prevent dry heating

monitor the flask liquid level and top up as needed

Low-boiling solvents (ether, dichloromethane) require a fume hood

— no open flames

The condenser top must remain open

— a sealed system will explode when heated

Do not

Never leave the apparatus unattended for extended periods — continuous extraction runs for hours and needs regular checks
Never use cracked glassware

Continuous Extraction Apparatus

Specifications

Component List

Product Description

I. How Continuous Extraction Works

II. What's in the Setup

III. Light vs Heavy Solvent Extractors

IV. Material & Workmanship

Applications

Trace Organic Enrichment

Natural Product Isolation

Drug Residue Analysis

Environmental Monitoring

Low Partition Coefficient Samples

User Guide

I. Before You Start

Assembly sequence

III. Cooling Water & Heating

IV. Monitoring

V. Shutdown

Care & Notes

Prevent dry heating

Low-boiling solvents (ether, dichloromethane) require a fume hood

The condenser top must remain open

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Continuous Extraction Apparatus

Specifications

Component List

Product Description

I. How Continuous Extraction Works

II. What's in the Setup

III. Light vs Heavy Solvent Extractors

IV. Material & Workmanship

Applications

Trace Organic Enrichment

Natural Product Isolation

Drug Residue Analysis

Environmental Monitoring

Low Partition Coefficient Samples

User Guide

I. Before You Start

Assembly sequence

III. Cooling Water & Heating

IV. Monitoring

V. Shutdown

Care & Notes

Prevent dry heating

Low-boiling solvents (ether, dichloromethane) require a fume hood

The condenser top must remain open

Related Apparatus Kits

Liquid-Liquid Extraction

Soxhlet Extraction

Simple Distillation

Reflux Apparatus

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