Molecular Trap / Reagent Trap Packs / Molecular Sieve
Biolytic Lab Performance. Inc. offers Molecular Traps that are designed to
remove unwanted moisture from various reagents. These Molecular Traps are offered
in two varieties.
There is a Molecular Trap designed to remove moisture from solvents. It is very
popular for drying reagents used in Oligo Synthesis and for maintaining low moisture
in these reagent if the reagents are left on a synthesizer for extended periods
of time.
There is also a Molecular Trap that is designed to remove moisture and amines from
DMF and NMP for peptide synthesis.
Molecular Traps, Stability Period
The Molecular Traps are useful in various solvents and have different stability
periods depending on the solvent they are placed in. The following is a table that
gives a listing of the solvents that the Molecular Traps are effective in. It also
breaks the solvents into two categories.
Category one contains reagents that the Molecular Traps are stable in for
longer than one month.
Category two contains reagents that the Molecular Traps are stable in for
up to one month.
General Solvent Exposure Table
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Category -1
Solvents Suitable for Extended Exposure
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Category - 2
Solvents Suitable for Exposure up to One Month
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Acetone
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Chloroform
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Acetonitrile
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Methylene Chloride
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Benzene
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Tetrahydrofuran
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Diethyl ether
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Dimethylformamide (DMF)
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Dioaxne
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Ethyl Acetate
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Ethanol (Anhydrous)
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Hexane / Heptane
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Methanol (Anhydrous)
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Methylethyl Ketone (MEK)
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N-Methylpyrolidinone (NMP)
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Molecular Traps in Oligo Synthesis
Molecular traps are used in Oligo Synthesis reagents to maintain low water in water
sensitive reagents. The Molecular Traps can be used for an extended period of time
in Oligo Synthesis Reagents without degradation of the packing material or the casing.
The determining factor for how long to use a Molecular Trap on oligo synthesis reagents
before changing to a new trap is really dependent on the amount of moisture the
molecular trap has been exposed to. The wetter the solvents, the shorter the
life of the molecular trap.
As a molecular trap absorbs moisture from the solvent its moisture absorbing capacity
diminishes. At some point the molecular trap will become saturated and will no longer
absorb moisture but it may release moisture into the solvent if the solvent is very
dry to begin with. Therefore it is important to not use molecular traps once they
have become saturated with water.
There is no visual indication of the moisture content of a molecular trap.
The user must judge the useful life based on the initial water content of the reagent
and the humidity in the air.
A relatively safe useful life time is 4 weeks or 4 bottles of solvent which ever
comes first.
Oligo Synthesis Reagent Table
(Click the trap size below to order)
* Amidites are purchased in dry powder form. Upon dissolving the amidite in Anhydrous
Acetonitrile, the molecular trap can be added.
Moisture Absorbing Action
Molecular Traps can dry solvents that start out slightly wet however it is recommended
that if the solvent contains more than 0.1% water 2 molecular traps be used per
bottle.
Reducing the moisture content of a reagent that is wet takes time. The user should
add the Molecular Trap and wait 24 to 48 hours before using it to make
sure that the water content has been reduced to a useable level (< 50 ppm).
Molecular Traps can also be used to maintain a low water content in solvents. This
process is ongoing and takes place at the same rate that moisture is absorbed by
the solvent if absorption is due to normal exposure while the reagent is attached
to an instrument.
Molecular Traps in Peptide Synthesis
Moisture & Amine Removing Molecular Traps
These molecular traps are designed to be used in DMF and NMP for Peptide Synthesis.
DMF is very hygroscopic. Moisture in DMF degrades DMF into carbon monoxide and dimethylamine
(DMA). DMA degrades fmoc amino acids and therefore is bad for fmoc peptide synthesis.
Molecular Traps have been shown to reduce moisture in DMF and NMP as well as remove
DMA from DMF.
Peptide Synthesis Reagent Table (Click the trap size below to order)
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Reagent
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Bottle Size, ml
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Trap Size
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DMF / NMP
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4000 ml
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20 gram
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DMF / NMP
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2000 ml
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12 gram
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DMF / NMP
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100 ml
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6 gram
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