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NUCLEODUR® MACHEREY-NAGEL's newest range of phases

For Technical Information

NUCLEODUR® is MACHEREY-NAGEL's newest range of phases, based on ultrapure spherical silica. The special surface bonding technology and the low concentration of metal ions lead to high efficiency symmetrical peaks.
The key features of NUCLEODUR® include:
  • Ultrapure silica
  • Excellent mechanical and chemical stability
  • Low level metal ions
  • Enhanced pH stability

Material Characteristics

Phase   Functional Group Encapped Particle Size (µm) Pore Size (Å) Surface Area (m2/g) Carbon Load
C18 Gravity
Yes1.8, 3, 511034018
C18 ec
OctadecylYes3, 511034017.5
C8 GravityOctylYes1.8, 511034011
C8 ecOctylYes3, 511034010.5
C18 PyramidOctadecylYes1.8, 3, 511034014
C18 IsisOctadecylYes1.8, 3, 511034020
Sphinx RPOctadecyl/PhenylYes1.8, 3, 511034015
CN and CN-RPCyanoYes3, 51103407
NH2 and NH2-RPAmino




NUCLEODUR® C18 Gravity and C8 Gravity are based on the ultrapure NUCLEODUR silica. The high density bonding of these phases leads to an extended operational pH range (1-11). This can be helpful for improving selectivity in method development and for more challenging applications.

NUCLEODUR® C18 ec and C8 ec

The NUCLEODUR C18 ec and C8 ec phases are recommended for routine analyses and for scaling up to preparative HPLC.


NUCLEODUR C18 Isis is a C18 bonded phase with specially cross-linked surface modification. This polymeric bonding leads to high steric selectivity and is therefore suited for separation of positional and structural isomers and planar/non-planar molecules. The phase has an enhanced pH stability of 1 to 10. Figure below demonstrates the increased steric selectivity of NUCLEODUR C18 Isis for o-terphenyl (non-planar) and triphenylene (planar) compared with a monomerically bonded C18 phase.

NUCLEODUR® C18 Pyramid

NUCLEODUR® C18 Pyramid is a C18 bonded phase with hydrophilic endcapping, designed especially for use with eluents containing up to 100% water. The phase also shows improved retention characteristics for very polar molecules, such as short chain organic acids.


  • Bifunctional C18/Phenyl phase
  • High density bonding
  • Low LC-MS bleed
NUCLEODUR® Sphinx RP is a bifunctional phase consisting of a well-balanced ratio of octadecyl and phenyl groups covalently bonded to the NUCLEODUR silica. The combination of classical hydrophobic with π-π interactions expands the scope of selectivity in comparison with conventional reversed-phase materials. NUCLEODUR Sphinx RP is particularly suited for the separation of molecules containing aromatic and multiple bonds. It may also outperform standard C18 phases for the separation of polar compounds. Figure below shows a comparison of the separation of flavonoids on three different NUCLEODUR phases.


NUCLEODUR HILIC is a zwitterionic modified stationary phase. The betaine character of the ammonium - sulphonic acid ligands results in an overall neutrally charged, but highly polar surface. This column is ideal for analysing polar analytes such as acids and bases, natural compounds, nucleosides, amino acids, water soluble vitamins etc. Due to its high loadability, NUCLEODUR HILIC is suitable for preparative applications.

NUCLEODUR® 1.8μm Phases

  • Ultra fast HPLC
  • Shorter columns with high separation efficiency
  • Significant improvement in resolution
  • Increased detection sensitivity

Increase in separation efficiency

An increase in plate number of approximately 67% in transferring from 3μm to 1.8μm particles offers the possibility of using shorter columns with equal plate numbers, resulting in a decrease in analysis time. Typically, for a 50 x 4.6mm NUCLEODUR C18 Gravity column:

3μm: N ≥ 100,000 plates/m

1.8μm: N ≥ 166,667 plates/m

Improvement in resolution

The use of 1.8μm instead of 3μm particles can lead to an increase in resolution of approximately 30%. This is illustrated in Figure below for the separation of naphthalene and ethylbenzene.

All of the NUCLEODUR® premium phases are now available in 1.8μm particle sizes. Columns packed with these microspherical particles show improvements in terms of plate numbers, column efficiencies and resolution, compared with their 3μm counterparts.

Column back pressure

The smaller particle size results in an increased back pressure. However, the high sphericity of the  NUCLEODUR particles and their very narrow particle size distribution means that back pressure is kept at a moderate level. In addition, the particles are fractionated in order to limit the increase in back pressure. Nevertheless, the use of columns packed with sub 2μm particles generally makes special demands on the HPLC equipment. Pumps should be designed for pressures of 250 - 1000 bar and the entire system should feature the lowest possible dead volume, for optimum column performance.

Higher flow rates and shorter run times

The optimal flow rate for 1.8μm particles is higher than for 3 and 5μm particles.

NUCLEODUR® Bulk Material

  • Ultra low metal content
  • Range of particle sizes
  • High loadability
NUCLEODUR® is an ideal material for scaling-up methods due to the availability of a wide range of particle sizes. The material provides a high mechanical bed stability and the narrow particle size distributions provide lower pressure drop due to the absence of fines. The material is reusable even after several cycles of repeated packing.
Particle TypeSpherical
Particle Size (µm)10, 12, 16, 20, 30, 50
Pore Diameter (Å)110
ChemistriesSilica, C18 ec
pH Range1 - 9

Contact Hichrom for further information