Capital HPLC

Pirkle Type Phases (Type I)

Pirkle Type Phases (Type I)

Syntechnic multiple-interaction chiral bonded phases, or more often known as “ Pirkle Phases” after their inventor, who developed the first commercially available version in 1981. This consisted of dinitrobenzoyl phenylglycine ionically bound to aminopropylsilica. This large and important class of chiral stationary phases, arose from the idea that the greater the number of specific, discrete, simultaneous interactions between chiral solute molecules and a chiral locus on the stationary phase, then the greater the likelihood of effective chiral discrimination, and hence chromatographic resolution of enantiomeric solutes.
Starting from this premise, approximately 100 chiral stationary phases of this type have been developed, each being relatively simple and well defined in structure, containing at least one each of three types of functional groups, near the chiral centre.
(i) p-acidic or p-basic aromatic groups, capable of donor-acceptor interaction (chargetransfer complexation).
(ii) polar hydrogen-bond and/or stacking sites. (iii) bulky non-polar groups, providing steric repulsion, van der waals interaction, and/or conformational control. They have been used to resolve thousands of
enantiomeric solutes, often with impressive selectivity and efficiency. Applications of these chiral stationary phases to the solution of synthetic, analytical and biomedical problems have begun to proliferate.

The following compound classes have been resolved directly on type I chiral stationary phases – alcohols,cyclic amides and imides, carboxylic acids, benzodiazepenones, phthalides, aromatic sulfoxides, phosphine oxides, binaphthols and lactams. Whereas the following classes of compounds can be separated as either their DNAn (dinitroanilide) or DNB (dinitrobenzoyl) derivatives for p-donor

chiral stationary phases – alcohols, thiols, amines, aminoalcohols, amino acids, and carboxylic acids. derivatization of secondary amines with arylchloroformates to afford carbamates tends to yield the best separations.
Type I chiral stationary phases tend to be used in the normal phase mode, using mobile phases of hexane, modified with 2-propanol, dichloroethane:ethanol, or tetrahydrofuran. Typically 2-propanol is the best modifier in terms of enantioselectivity, although the addition of a small amount (0.5-2%) of acetonitrile to this mobile phase, may improve the observed resolution (RS value) especially for amides (although typically the separation factor (a) will decrease). Multiple-interaction chiral stationary phases have occasionally been used in the reverse phase mode (2), but where direct comparisons with normal phase mode are possible, enantioselectivity is typically diminished. Advantages of type I chiral stationary phases include their usefulness in preparative scale separations, their high applicability and efficiencies, and for trace analysis the ability to select the (R) or (S) configuration of the chiral stationary phase in which the trace component elutes first, hence increasing sensitivity.

 

 

The DNBLeu stationary phase is not as widely applicable as the DNBPG phase, but often produces better separations for example
the benzodiazepine class of compounds.

The use of a 3μm base material for the above two CSPs with its inherent higher efficiency (typically60, 000-100,000 plates per metre)
results in improved peak shape (hence reducing peak overlap in partially resolved separations) and increased sensitivity (see example below).

YMC-PAK K Series

A R(+)-naphthylethylamine (p-donor) polymeric phase, bonded to a 300Å pore silica, as shown below.
The phase can be used to separate racemic mixtures of alcohols, amines, amino alcohols, carbonic
acids, and a-hydroxycarbonic acids, but often they will require pre-column derivatization.

Spherisorb Chiral 1

(R)-phenylmethylurea groups covalently bonded to 5μm silica, and results in a p-donor CSP. The
strength of the p-interaction and the usefulness of the phase maybe enhanced by the introduction of
a 3,5-dinitrobenzene group into the molecule to be separated.

Ordering Information

 
Please use the following catalogue numbers when ordering Type I chiral stationary phases. For
prices see our general price list page 17.

 

StationaryPhase

ColumnType

Dimensions

Product

Price

   

(mm)

Code

 

ChiralCap(R)-DNBPG(3µm)

column

250x4.6

1A3125

 
 

cartridge

250x4.6

1A3325

 
 

cartridge

150x4.6

1A3315

 
 

guardcartridge

20x4.6

1A3302

 
         

ChiralCap(S)-DNBPG(3µm)

column

250x4.6

1B3125

 
 

cartridge

250x4.6

1B3325

 
 

cartridge

150x4.6

1B3315

 
 

guardcartridge

20x4.6

1B3302

 
         

ChiralCap(S)-DNBLeu (3µm)

column

250x4.6

1C3125

 
 

cartridge

250x4.6

1C3325

 
 

cartridge

150x4.6

1C3315

 
 

guardcartridge

20x4.6

1C3302

 
         

BAKERBOND(R)-DNBPG(5µm)

column

250x4.6

2A5125

 
         

BAKERBOND(S)-DNBLeu (5µm)

column

250x4.6

2C5125

 
         

NUCLEOSILCHIRAL-2(5µm)

column

250x4.6

5L5125

 
         

YMCA-KO3(5µm)

column

250x4.6

6N5125

 
         

SpherisorbChiral 1(5µm)

column

250x4.6

7P5125

 
 

cartridge

250x4.6

7P5325

 
 

cartridge

150x4.6

7P5315

 
 

guardcartridge

20x4.6

7P5302

 
         

SpherisorbChiral 2(5µm)

column

250x4.6

7R5125

 
 

cartridge

250x4.6

7R5325

 
 

cartridge

150x4.6

7R5315

 
 

guardcartridge

20x4.6

7R5302

 
         

CartridgeHoldersfor:

 

250x4.6

1Z0425

 
   

150x4.6

1Z0415

 
   

20x4.6

1Z0402

 
         

 

 

 

 

 

 

 

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