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Reprosil Chiral-AM / OM / NR
Reprosil Chiral-AM and Reprosil Chiral-OM are new Polysaccharide chiral stationary phases. The chiral selectors are Amylose-Tris-(3,5-dimethylphenyl)-carbamate for Chiral-AM or Cellulose-Tris-(3,5-dimethylphenyl)-carbamate for Chiral-OM. The selectors are bound to a 5 µm ultrapure silica with 1000 A° pores.
Dr. Maisch company offers them in 2 different CPS versions: Reprosil Chiral-AM and Chiral-OM are designed for separations in normal phase mode, Reprosil Chiral-AM-RP and Chiral-OM-RP for separations in reversed phase mode.
Both Reprosil Chiral-AM and Chiral-OM columns have a very broad generality and are able to separate neural, acidic and basic racemates. Nearly each 2. known racemic compound can be separated.
Eluents:
In Normal phase mode typical eluents are hexane / IPA or heptane / IPA mixtures.
Basic samples: To prevent peak tailing of basic compounds please add 0.1 – 0.5 % Diethylamine or Triethylamine. Acidic samples: To prevent peak tailing of acidic compounds please add 0.1 – 0.5 % TFA or acetic acid.
In Reversed phase mode typical eluents are Acetonitrile / Water mixtures. You can use also MeOH or Ethanol instead of Acetonitrile. The water content must be below 85 %.
For basic compounds please use 0,5 – 1 N Perchlorate or 0.1 % TFA. For acidic compounds please use HClO4 / NaClO4 buffers together with ACN .
Attention:
Please never use with Reprosil Chiral-AM and Reprosil Chiral-OM the following eluents, which may destroy the phase:
Ethers, THF, Dioxane, Dichlormethane, Chloroform, Ketones, Ethylacetate, DMSO, Dimethylformamide (DMF), Dimethylacetamide and 50-100 % IPA.
Applicationes with Reprosil Chiral-OM
The most frequently used column dimension is 250 x 4.6 mm with a flow between 0.5 – 2.0 ml/min.
Abscisinic acid:
Alprenolol:
Atropin:
Benzoin:
2-Butyl-Phenylcarbamate:
Carbinoxamine:
Carteolol:
Cyclopentolate:
Flavanone:
Guaifenesine:
Homatropine:
Hydroxyzine:
Ibuprofen:
Ibuprofenpiconol:
Metoprolol:
Perisoxal:
α-Phenylethanol:
2-Phenylpropionic acid:
Pindolol:
Practolol:
Propranolol:
Sulconazol:
trans-Stilbenoxide:
Warfarin: |
Hexane / Isopropanol (80/20) + 0,1% TFA
Hexane / Isopropanol (80/20) + 0,1% Diethylamine
Hexane / Isopropanol (80/20) + 0,1% Diethylamine
Hexane / Isopropanol (90/10)
Hexane / Isopropanol (90/10)
Hexane / Isopropanol (90/10)
Hexane / Isopropanol (90/10)
Hexane / Isopropanol (90/10)
Hexane / Isopropanol (90/10)
Hexane / Isopropanol (80/20) + 0,1% Diethylamine
Hexane / Isopropanol (80/20) + 0,1% Diethylamine
Hexane / Isopropanol (90/10)
Hexane / Isopropanol (99/1) + 0,1% TFA
Hexane / Isopropanol (90/10)
Hexane / Isopropanol (80/20) + 0,1% Diethylamine
Hexane / Isopropanol (90/10)
Hexane / Isopropanol (90/10)
Hexane / Isopropanol (98/2) + 1% Formic acid
Hexane / Isopropanol (80/20) + 0,1% Diethylamine
Hexane / Isopropanol (80/20) + 0,1% Diethylamine
Hexane / Isopropanol (80/20) + 0,1% Diethylamine
Hexane / Isopropanol (90/10)
Heptane / Isopropanol (85/15)
Hexane / Isopropanol (70/30) + 0,1% TFA |
Reprosil Chiral OM-RP
In Reversed phase mode typical eluents are Acetonitrile / Water mixtures. You can use also MeOH or Ethanol instead of Acetonitrile. The water content must be always below 80 %.
For basic compounds please use 0,5 – 1 N Perchlorate or 0.1 % TFA. For acidic compounds please use HClO4 / NaClO4 buffers together with ACN.
Alimemazine : Na-Perchlorate 1N / ACN (60/40)
Hydroxyzine : Na-Perchlorate 1N / ACN (60/40)
Indapamide : H20 / Acetonitrile (60/40)
Phenylbutyric acid: Na-Perchlorate-Perchloric acid 0.5N, pH2 / ACN (60/40)
1-Phenoxy-2-Propanol: H20 / Acetonitrile (60/40)
4-Phenyl-2-Butanol: H20 / Acetonitrile (70/30)
Pindolol: Na-Perchlorate: 1N / ACN (60/40)
Propanolol: Na-Perchlorate: 1N / ACN (60/40) or: Acetonitrile / 0,1 % TFA (30/70)
Trimipramine: Na-Perchlorate 1N / ACN (60/40)
Verapamil: Na-Perchlorate 1N / ACN (60/40)
Comparison of 3 different Chiral columns from Dr. Maisch:
- Reprosil Chiral-NR, a brush-type phase with p-electron donor- and p-electron acceptor groups, covalently bound to a 100 A° 8 µm silica. Stable in all HPLC eluents. Very high preparative capacity.
- Reprosil Chiral-OM, a 1000 A° silica phase modified with cellulose-tris(3,5-dimethylphenyl) carbamate.
- Reprosil Chiral-AM, a 1000 A° silica phase modified with Amylose--tris(3,5-dimethylphenyl) carbamate.
Table 1. Chromatographic properties of the neutral racemates.
Eluent: Heptane / IPA (90/10), Flow: 1 ml/min, Column dimension: 250 x 4.6 mm
Column |
ReproSil-Chiral-NR |
Reprosil Chiral-OM |
Reprosil Chiral-AM |
Benzoin |
a = 2,6
k'1 =2,4
N =7500 |
a = 1,5
k'1 =2,7
N =6800 |
a = 1,4
k'1 =5,5
N =14000 |
1,1-Binaphtol |
a = n.s.
k'1 = 1,2
N = |
a =1,2
k'1 = 3,7
N = 2600 |
a = 1,3
k'1 = 10,0
N = 6200 |
Trans-Stilbenoxide |
a = 3,3
k'1 = 0,78
N = 8900 |
a = 2,3
k'1 = 0,8
N = 8300 |
a = 3,4
k'1 = 0,79
N = 1300 |
2,2,2-Trifluoro-1-(9-anthryl)Ethanol |
a = 1,2
k'1 = 1,3
N = 6500 |
a = 3,2
k'1 = 2.0
N = 3900 |
a = 1,5
k'1 = 2,0
N = 10000 |
Table 2. Chromatographic properties of the basic racemates.
Eluent: Heptane / IPA (90/10) + 0,1 DEA, Flow: 1 ml/min, Column dimension: 250 x 4.6 mm
Column |
ReproSil-Chiral-NR |
Reprosil Chiral-OM |
Reprosil Chiral-AM |
Bupivacine |
a = 1,5
k'1 =5,7
N = 5800 |
a = 1,15
k'1 =0,6
N = 4600 |
|
Carbinoxamine |
a = 1,2
k'1 = 5.0
N = 400 |
a =1,4
k'1 = 0,7
N = 7500 |
a = 1,4
k'1 = 1,3
N = 10000 |
Clenbuterol |
a = 1,4
k'1 = 2,1
N = 3800 |
a = no separation
k'1 = 0,7
N = |
a = no separation
k'1 = 1,9
N = |
| Ketamine |
a = 1,1
k'1 =2.0
N =6200 |
a = 1,2
k'1 =1,1
N = 6500 |
a = 1,0
k'1 =1,2 |
Oxamniquine |
a = 1,1
k'1 = 10,6
N = 3100 |
a = 1,1
k'1 =3,8
N =3100 |
a = 1,2
k'1 =5,6
N = 10400 |
Oxprenolol |
a = 1,3
k'1 = 2,3
N = 3000 |
a = 6,3
k'1 = 1,9
N = 3200 |
a = 1,7
k'1 = 1,1
N = 9000 |
1-(1-Phenyl)-ethylamine |
a = no separation
k'1 = 2,2
|
a = 1,3
k'1 = 1,1
N = 7500 |
a = no separation
k'1 = 0,5
N = |
Troeger’s base |
a = 1,9
k'1 = 1,1
N = 5900 |
a = 1,3
k'1 = 1,0
N = 6000 |
a = 1,8
k'1 = 0,8
N = 9000 |
Table 3. Chromatographic properties of the acidic racemates.
Eluent: Heptane / IPA (90/10) + 0,1 TFA , Flow: 1 ml/min, Column dimension: 250 x 4.6 mm
Column |
ReproSil-Chiral-NR |
Reprosil Chiral-OM |
Reprosil Chiral-AM |
CBZ-Alanine (210 nm) |
a = 1,3
k'1 = 3,2
N = 5700 |
a = 2,9
k'1 = 2,0
N = 3100 |
a = 2,1
k'1 = 3,7
N = 9200 |
Flurbiprofen |
a = 1,3
k'1 = 1.0
N = 6900 |
a =1,1
k'1 = 0,7
N = 6000 |
a = 1,7
k'1 = 1,2
N = 11600 |
Sulindac |
a = no separation
k'1 = 3,0
|
|
a = 1,4
k'1 = 1,9
N = 10200 |
Proglumide
Eluent: Heptane/EtOH (9/1)+ 0,1 TFA |
a = 1,6
k'1 = 4,3
N = 5900 |
a = 2,2
k'1 = 0,7
N = 3800 |
a = 1,8
k'1 = 2,4
N = 5000 |
Rules of Thumb
for chiral
separation |
Reprosil Chiral-NR:
-Needs an Oxygen at or
near the chiral centre +
an aromatic ring.
-More predictable.
-Inversion of elution
order possible.
-Very high prep. capacity
-Stable in all HPLC-
eluents. |
Reprosil Chiral-OM:
-High versatile chiral
phase.
-No aromatic ring
necessary.
-No inversion of
elution order possible
-Scale up possible
-Caution: Not stable in
all eluents. |
Reprosil Chiral-AM:
-Highest generality of
all chiral phases.
-No aromatic ring
necessary.
-No inversion of elution
order possible
-Scale up possible
-Caution: Not stable in
all eluents. |
Conclusion: With these 3 chiral phases the majority of known racemates can be separated. |
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