Ascentis® Express C30 UHPLC Columns

Excellent selectivity for very hydrophobic compounds, long-chain and structurally related isomers

The Ascentis® Express 160 Å C30, based on Fused-Core® particles, is nonpolar in nature. This column is best utilized with mobile phases that are mixtures of methanol and water or acetonitrile and water. Higher levels of the organic solvent component will typically reduce the retention of the sample compounds.  Separations based on shape selectivity generally show increased resolution at lower temperatures so an effective method development strategy will explore ambient and sub-ambient conditions. Using elevated temperatures (e.g., 40 – 60 °C) will reduce the viscosity of the mobile phase and allow the use of faster flow rates for high sample throughput. Gradient elution techniques using 5 -10% organic component as the initial mobile phase and increasing to 100% organic component as the final mobile phase often can affect separations of complex sample mixtures in minimal time.

Ascentis® Express 160 Å C30 columns are highly suited for the reversed-phase separation of geometric and positional isomers. Ionizable compounds, such as acids and bases, are generally best separated with mobile phases buffered at pH of 2 to 3. The use of 20-50 mM buffers is always recommended for optimum results and long-term stability when separating ionizable compounds.

Ascentis® Express 160 Å C30 is a high-speed, high-performance liquid chromatography column based on a superficially porous Fused-Core® particle design. The Fused-Core® particle provides a thin porous shell of high-purity silica surrounding a solid silica core. This particle design exhibits very high column efficiency due to the shallow diffusion paths.

 

Ascentis Express C30 Specifications
Silica: Type B
(High purity silica)
Particle Platform: Superficially porous
particles (SPP)
Phase Chemistry: Triacontyldimethly
Particle Size: 2.7 µm
Pore Size: 160 Å
Carbon Load: 4.5%
Surface Area: 90 m²/g
pH Range: 1-9
Max Temperature
at Low pH:
60 °C
Max Temperature
at High pH:
40 °C
Endcapped: Yes

Fused-Core® particle size 2.7 µm

Figure 1. Ascentis® Express UHPLC and HPLC columns

 

Separation of hydrophobic vitamins

These columns show increased retention and baseline resolution of vitamin K1 trans and cis isomers compared to a competitive SPP C30 column. Since the cis isomer of K1 is biologically inactive, it is important to know how much of each isomer is present in vitamin enriched products.

 

Separation of Hydrophobic Vitamins

Figure 2. Separation of Hydrophobic Vitamins

 
Columns Ascentis® Express 160 Å C30, 15 cm x 4.6 mm I.D., 2.7 μm
Competitive SPP C30, 15 cm x 4.6 mm I.D., 2.7 μm
Mobile Phase A: Water
Mobile Phase B: Methanol
Isocratic: 95% B
Flow Rate: 1.5 mL/min
Temperature 25 °C
Injection Volume 1 μL
Detection: PDA at 280 nm
Vitamins 1. Menadione (K3)
2. Menaquinone 4 (K2)
3. 2,3-trans-phylloquinone (K1)
4. cis-phylloquinone (K1)

Materials

     
Related Links