Partnumber , Name , Description , Loading
R51230B :
SiliaBond Propylsulfonic Acid (SCX-2) Acid and Ion Exchanger , 1 mmol / g
R60530B : Si-Tosic Acid Strong cation exchange (SCX)
, 0.8 mmol / g
R65530B : SiliaBond TBA Chloride Ion Exchanger 0.5 mmol
/ g , 014 % carbon
R66530B : SiliaBond TMA Chloride Ion Exchanger 1.2 mmol
/ g , 14 % carbon
R70030B : SiliaBond Carboxylic Acid Acid and Ion Exchanger
4.5 % carbon , 1.6 mmol / g
SiliaBond Propylsulfonic Acid (SCX-2)
Product Data Sheet:
Part Number: R51230B
Loading: 1 mmol / g
Particle Size: 40 - 63 µm
Pore Size: 60
Specific surface area: 500 m²/g
Description: Acid and Ion Exchanger
Technical Information
Supported sulfonic acids such as SiliaBond Propylsulfonic Acid (or SiliaBond SCX-2) are in a class of strong acids widely used in different fields of synthetic organic chemistry. Their applications are well known and are used in a large number of settings going from drug discovery laboratories up to manufacturing processes. Among the applications, we denote their use as acid catalysts, stationary phases for ion chromatography, and basic impurity scavengers. Meanwhile, the most common use is probably as strong cation exchanger (SCX) for the amine “Catch and Release” purification in SPE cartridge. This technique is becoming so popular that some universities are introducing the use of SCX SPE purification in their undergraduate teaching laboratories.
SiliCycle offers the SiliaBond Propylsulfonic Acid and the SiliaBond Tosic Acid (SCX). Both are considered as strong cation exchanger, meaning that they maintain a negative charge throughout the pH scale. The aromatic ring of the SiliaBond Tosic Acid makes it slightly more acidic than the other. However, internal tests have demonstrated that they both have comparable strength. The difference between the two products is mainly in the selectivity. As a matter of fact, the SiliaBond SCX-2 presents a slightly more non-polar character than the SiliaBond SCX, thus reducing secondary non-polar interactions with compounds. Here we report some results obtained for amine purification using SPE cartridges (see the section of SiliaBond Tosic Acid for additional results).
Catch and release of amine with SiliaBond Propylsulfonic Acid (SCX-2)
| Amine | # eq. | Catch | Release |
| Tributylamine | 2 | 98 % | 90 % |
| Tributylamine | 4 | 100 % | 100 % |
| Aniline | 2 | 100 % | 100 % |
| 2-Aminothiazole | 4 | 100 % | 100 % |
| 4-Nitroaniline | 4 | 100 % | 100 % |
Bulk procedure for scavenger :
To the crude reaction mixture, add 2-4 eq. of SiliaBond Propylsulfonic Acid and let it stir for one hour, then filter and wash.
SPE procedure for amine Catch and Release purification with SiliaBond Propylsulfonic Acid SPE
Amine (1 eq.) was dissolved in methanol (2500 ppm)
SPE cartridge : 0.5 g (2 eq.) or 1 g (4 eq.)
1 – Column conditioning : 10 mL of methanol
2 – Sample application
3 – Wash with 10 mL of methanol (1 mL/min)
4 – Release : 10 mL of 2 M ammonia/methanol
Solvent compatibility: All solvents, aqueous and organic
Prolonged storage: Keep dry
Product Data Sheet:
Part Number: R60530B
Loading: 0.8 mmol / g
Particle Size: 40 - 63 µm
Pore Size: 60
Specific surface area: 500 m²/g
Description: Strong cation exchange (SCX)
Technical Information
Silica-bound Tosic Acid (TsOH) is a versatile bound strong acid with a pKa << 1. It is widely used to separate basic peptides or proteins and in "Catch and Release” amine purification.
Si-TsOH has been optimized for use in organic applications. It will not dissolve in methanol or any other solvent. It delivers much higher recovery and has better flow characteristics than polymer.
Sample Procedures
Catch and Release Amine Purification: Add 2-4 eq. to the crude reaction mixture,
stir for 10 min., then filter to remove non basic impurities. Wash with DCM
followed by 2 M ammonia in MeOH or MeOH/DCM to release amines.
Solvent compatibility: all solvents aqueous and organic, Working pH: 2-12
Prolonged storage: keep dry
Product Data Sheet:
Part Number: R65530B
Loading: 0.5 mmol / g
14 % carbon
Particle Size: 40 - 63 µm
Pore Size: 60
Specific surface area: 500 m²/g
Description: Ion Exchanger
Technical Information
SiliaBond TBA Chloride (or Si-TBACl) may be used in the same way as SiliaBond
TMA Chloride. Si-TBACl is more sterically hindered which confers a different
selectivity than other anion exchangers.
Solvent compatibility: All solvents, aqueous and organic
Prolonged storage: Keep dry
SiliaBond TMA Chloride
Product Data Sheet
Part Number: R66530B
Loading: 1.2 mmol / g
14 % carbon
Particle Size: 40 - 63 µm
Pore Size: 60
Specific surface area: 500 m²/g
Description: Ion Exchanger
Technical Information
SiliaBond TMA Chloride (or SiliaBond SAX, Si-TMACl) is mainly used as a strong anion exchanger (SAX) in ion chromatography1,2 and ion exchange SPE. The function bears a positive charge across the whole pH range as well as in organic solvents. It is especially used for the "Catch & Release" purification of weak acids. For the purification of strong acids, a weak anion exchanger (WAX) such as SiliaBond Triamine, Amine or Diethylamine is preferred. Since the chloride ion is bound relatively strongly to the ammonium, it may be suited to activate the ion exchanger by changing the chloride for an acetate counter ion. This can be done following the procedure described below.
1) J. Chromatogr. 119 (1976) 25
2) J. Chromatogr. 123 (1976) 109
Sample Procedures
Counter anion exchange chloride for acetate in SPE
Rinse the column with deionized water. Prepare a 0.1 M solution of acetic acid/acetate buffer and rinse the cartridge with 2 times its volume. Equilibrate the column with 1 column volume of 10 mM of the same buffer.
Catch & Release purification of weak acids, Use the preparation as described above
1) Sample application
2) Interference elution: use the equilibration buffer to which 10-30% of an organic solvent (MeOH or ACN) may be added to remove organic non-ionized species. In order to make sure the analyte is not eluted in this part, test its presence in the filtrate before continuing.
3) Analyte elution: The analyte may be eluted by increasing the ionic strength of the eluent to 0.1-0.3 M. It is also possible to neutralize the charge of the analyte by lowering the pH to two units below its pKa. If the analyte is in organic solvent, use 5% of acetic acid in methanol.
Solvent compatibility: All solvents, aqueous and organic
Prolonged storage: Keep dry
SiliaBond Carboxylic Acid
Product Data Sheet:
Part Number: R70030B
Loading: 4.5 % carbon
1.6 mmol / g
Particle Size: 40 - 63 µm
Pore Size: 60
Specific surface area: 500 m²/g
Description: Acid and Ion Exchanger
Technical Information
Synthesis
SiliaBond Carboxylic Acid (or Si-CAA) can be used as a scavenger for amines and carbonates and for the quenching of alkoxides and organometallic reagents.
Separation
SiliaBond Carboxylic Acid is primarily used as a weak cation exchanger (WCX) in solid phase extraction (SPE) and in HPLC. It is the cation exchanger preferred over SiliaBond Tosic Acid (SCX) when performing "Catch and Release" purification of compounds bearing a permanent positive charge such as tetraalkylammoniums. Using the SCX in this case could make the release of the compound of interest difficult not to say irreversible due to the strong interaction between the two strong ions. SiliaBond Carboxylic Acid has a pka of ~ 4.5. It can also be used in ion exchange chromatography (IEC) and has a different selectivity than bound tosic acid.1,2
1) J. Chromatogr., 117 (1976) 269
2) J. Chromatogr., 123 (1976) 109
Sample Procedures
General Use: Add
2-4 eq. to the crude reaction mixture, stir for 1 h, then filter.
Solvent compatibility: All solvents, aqueous and organic
Prolonged storage: Keep dry