NUCLEOSHELL® core-shell silica phases for HPLC

Features

NUCLEOSHELL®

Core-shell technology:
Solid core of silicon dioxide,
homogeneous shell of porous silica

Highest efficiency compared to traditional totally porous materials

Pore size 90 Å; particle size 2.7 µm (core 1.7 µm); specific surface 130 m2/g

Lower back pressure also allows use on conventional LC systems

Pressure stability up to 600 bar

NUCLEODUR®

Summary of available NUCLEOSHELL® phases

Phase

Modification

% C

pH range

Particle size [µm]

USP

Structure

RP 18

Octadecyl, multi-endcapping

7.5

1–11

2.7

L1

Phenyl-Hexyl

Phenyl-Hexyl, multi-endcapping

4.5

1-10

2,7

L11

PFP

Pentafluorophenyl, multi-endcapping

~ 3

1–9

2.7

L43

HILIC

Ammonium – sulfonic acid

1.3

2–8.5

2.7

–

Demands on HPLC separations are constantly increasing with respect to separation efficiency and detection limits as well as concerning the time requirements for each analysis. Core-shell technology sets new standards for increasing efficiency in research and quality control.

Benefits of core-shell technology

Core-shell particles vs.
totally porous silica gel

Short diffusion paths

Rapid mass transfer (C term of the Van Deemter equation)

High flow velocity without peak broadening for fast LC

Narrow particle size distribution (d90/d10 ~ 1.1)

Stable packing

High heat transfer

Minimized influence of frictional heat

Column efficiency of NUCLEOSHELL® ~ 250000/m (HETP ~ 4 µm)

Resolution Rs as function of particle size

Columns:

50 x 4 mm
NUCLEOSHELL® RP 18, 2.7 µm
NUCLEODUR® C18 Gravity, 3 µm
NUCLEODUR® C18 Gravity, 1.8 µm

Eluent:
Flow rate:
Temperature:
Detection:

acetonitrile – water (60:40, v/v)
1 mL/min
25 °C
UV, 254 nm

Peaks:
1. Naphthalene
2. Ethylbenzene

Better resolution at
lower back pressure and
shorter retention time