Chirality Classroom | Choose the right chiral column and never worry about distinguishing between left and right rotation again

Life is composed of carbon-based elements, and when carbon atoms form organic molecules, four atoms or groups can form a three-dimensional spatial structure through four covalent bonds. Due to the different connected atoms or groups, it can result in two types of molecular structures. Although these two types of molecules have exactly the same physical and chemical properties, they are still distinct molecules. This situation is similar to objects inside and outside a mirror, appearing to correspond to each other. Due to their three-dimensional structures, they cannot overlap no matter how they are rotated, just like our left hand and right hand, hence they are called chiral molecules. What is the mysterious science behind the world of chirality? Let’s explore together!

Objects inside and outside a mirror correspond to each other and will never overlap no matter how they are rotated.

1. Chiral substances

Levocarnitine, Dextrocarnitine – Levocarnitine aids in weight loss, while Dextrocarnitine is toxic.

Levoglucosan, Dextroglucosan (the nemesis of the human body) – Levoglucosan is beneficial, while Dextroglucosan is toxic.

Glucose has Dextro-rotatory and Levorotatory forms, but the human body can only metabolize Dextroglucose and cannot utilize Levoglucose. Utilizing Levoglucose can enhance the sweetness of food without increasing energy intake.

2. Chiral separation

Substance and Enantiomers (Enantiomorphs) in relation to their Chirality:

Instruments:

LC: Liquid Chromatography

GC: Gas Chromatography

SFC: Supercritical Fluid Chromatography

CE: Capillary Electrophoresis

Detectors: UV (Ultraviolet Detector)

Mobile Phases: Normal Phase, Reverse Phase, CO2

Sample Solubility: Alcohol, Hexane, Water, Acidic/Basic Solvents

Tips: Racemic mixture refers to a 1:1 mixture of a substance and its enantiomer.

Note: “Enantiomers” refers to the non-superimposable mirror-image isomers of a chiral compound.

3. Chiral Column Types:

Brush or Prikle Type
Cellulose Type
Cyclodextrin Type
Macrocyclicantibiotics Type
Protein Type
Ligand Exchange Type
Crown Ethers Type

4.Welch chiral columns

Welch Materials, Inc., specializes in polysaccharide-based coated chiral column products and has accumulated significant expertise in chiral separation and purification. The Ultisil® chiral stationary phase filler is a spherical silica gel coated with chiral polymers (linear starch derivatives or cellulose derivatives). The unique surface modification technology and coating process ensure the reproducibility and durability of Welch Materials’ chiral columns. The company focuses on the development of chiral fillers, continuously optimizing the process to ensure a wide range of applications for Welch Materials’ chiral fillers. Additionally, Welch Materials has successfully launched and achieved scale sales of chiral preparative fillers, semi-preparative columns, and preparative columns in 5μm and 10μm specifications. In the future, Welch Materials will provide chromatography users with even higher quality chiral separation and purification products and services.

5. Welch chiral fillers

6. Chiral application spectra.

Guidelines for using chiral columns:

1. Common solvents used are ethyl acetate, dichloromethane, chloroform, tetrahydrofuran, toluene, acetone, DMF, DMSO, and tert-butyl methyl ether.
2. Normal phase mobile phase typically consists of hexane, isopropanol, ethanol, trifluoroacetic acid, acetic acid, diethylamine, and triethylamine.
3. If the mobile phase contains bases, it should be flushed immediately after using the column.
4. Reverse phase mobile phase generally consists of water, methanol, acetonitrile, phosphate salts, and perchlorate salts.
5. When using high proportions of methanol and acetonitrile (>50%) as the normal phase mobile phase, a transition of 20 column volumes with isopropanol is necessary.
6. Avoid water contact with normal phase columns. In case of accidental water contact, rinse promptly with isopropanol.
7. Maintain pressure around 6 MPa for 5 μm chiral columns.
8. Keep the temperature of the chiral column below 30 degrees Celsius.