Solvent Purification

Definition of solvent purification

Solvent purification is to remove the unwanted particles or impurities in the solvents or reagents by distillation, recrystallization or filtration. Solvent filtration is one of solvent purification techniques that is commonly used in pre-treatment of precise analysis like HPLC.

Most common grades for reagents & solvents

Organic solvents are widely used in many laboratory experiments in different purity grading. Below listed the most common grades.

Guarantee Reagent, GR
Reagent Grade, RG
Analar Reagent, AR
American Chemical Society, ACS
United States Pharmacopoeia, USP
Analysis
Chromatography (HPLC, GC)

Solvent purification is essential for several analysis including mobile phase in HPLC (high performance liquid chromatograph) and LC-MS-MS (liquid chromatography-tandem mass spectrometry) to prevent impurities to effect experiment results or production rate.Such purification are often executed with vacuum filtration.

Solvent filtration process

Filtration is a technique of solvent purification used either to remove solid impurities from an organic solution by isolation the solids on the membranes. The membranes should be selected according to sample characteristics, removal rate, and filtration time.

There are 2 common solvent filtration methods, gravity filtration and vacuum filtration. Vacuum filtration uses pressure differences to accelerate filtration thus is generally much faster than gravity filtration.

Solvent filtration apparatus and assembly

A solvent filtration kit usually includes a chemical-resistant vacuum pump, a safety trap, a receiver flask and a set of filter holder.

A. Chemical resistant vacuum pump

Most solvent that requires purification are organic solvents, acids and alkaline, thus considering safety of analysts and resistance of the pumps, chemical-resistant pumps are recommended.

All wetted parts of ROCKER’s chemical-resistant vacuum pump are made of corrosion-resistant materials.
－ Chemker Chemical Resistant Vacuum Pump
Made of PTFE, provides high resistance to corrosive and aggressive gases.
－ Rocker C PTFE-coated Pump
PTFE-coated, provides moderate resistance to most chemicals including alcohol and alkane.
Chemker Chemical-resistant Pump

B. Receiver flask and filter holder

Borosilicate glass is the recommended material of receiver flask and filter holders used for solvent filtration in order to prevent damages caused by organic solvents and corrosive chemicals. Materials of the membrane support can be either fritted glass or stainless steel based on requirements.

ROCKER’sVF Filtration Apparatus
– Borosilicate glass-made, high resistance to heat and chmicals
– Clear scale marking for precise and easier sample addition
– Optional sintered glass-made or stainless steel-made filter support screen
– Spill-proof silicone baseVF3、VF6、VF7
Rocker 300C-VF12 Solvent Purification System