一区二区三区日韩_4388成人网_26uuu亚洲_在线欧美不卡_欧美日韩免费观看视频_欧美激情图区_国产一二三区精品_亚洲国产另类久久久精品极度_日日骚久久av_成人免费毛片app

SUPELCO Astec CHIRALDEX B-TA手性氣相色譜柱 毛細管柱
 

• D Type: β (beta)
• Derivative: Trifluoroacetyl
• Temp. Limits: -10 °C to 180 °C (isothermal or programmed)

    Incorporates a phase consisting of a 2,6-di-O-pentyl-3-trifluoroacetyl derivative of β-cyclodextrin.

    Trifluoroacetylation of the 3 position hydroxyl groups after pentylation of the 2,6 hydroxyl groups creates a phase with high selectivity for oxygen containing analytes in the form of alcohols, ketones, acids, aldehydes, lactones, and halogenated compounds.

Features: 

• Separates the widest variety of enantiomers
• Separates the greatest number of enantiomers
• Gamma more selective than beta form
• Unique retention behavior
• Extraordinary versatility and chiral selectivity

Analytes:

  Useful for homologous series of:

• Amino acids (primary, secondary, aromatic and aliphatic)
• Amines (primary, secondary, cyclic, aromatic and halogenated)
• Amino alcoholsAlkanes, hydrogenated alkanes
• Alcohols (aliphatic and aromatic)
• Acids (halogenated and hydroxy)
• Esters (aromatic, aliphatic, hydroxy, di-ester)
• DiolsLactones
• Ketones
• Phthalides
• Sulfoxides

Mechanism Observations:

• Strong dipole-dipole interactions
• Longer alkyl chain; greater retention; increase in enantioselectivity up to C4/C5
• Halogens known to favor cavity interaction

    Dipole-dipole interactions are commonly identified in the mechanism of separation for TA phases. In a homologous series of alkane enantiomers, identical alpha values are observed regardless of chain length or branching indicating only 1 or 2 carbons may be contributing to chiral recognition. Alpha values are greatly affected by size and polarity of the head group. Functional groups like epoxides, amino alcohols and alcohols can dictate the cyclodextrin selection. Aldehydes, carboxylic acids and epoxides separate better on the gamma while alcohols, alcohol amines and other linear molecules separate better on the beta derivative.

SUPELCO Astec CHIRALDEX B-TA手性氣相色譜柱 毛細管柱 訂貨信息：