Catalog Number - 65518-15P

Zx Similars C18™ is a traditional reversed-phase HPLC stationary phase manufactured on high-purity Type-B spherical silica with a fully endcapped octadecyl (C18) bonded phase. Designed as a cost-effective alternative to Agilent Zorbax® C18 columns, it offers comparable chromatographic behavior for USP L1 methods while providing the strong hydrophobic retention, reproducibility, and broad applicability expected from a conventional C18 stationary phase.

65518-15P is a 150 mm x 4.6 mm ID analytical column packed with 5 µm Zx Similars C18 particles. The 150 mm length provides an excellent balance of resolution and analysis time, making it suitable for routine analytical methods, pharmaceutical testing, and quality control applications. The 5 µm particle size provides excellent robustness, broad method compatibility, and lower operating pressure than smaller particle columns, making it well suited for conventional HPLC systems. Typical operating flow rates are approximately 1.0–2.0 mL/min.

This USP L1 column is ideal for hydrophobic and neutral compounds requiring strong reversed-phase retention. Common applications include pharmaceutical analysis, long-chain fatty acid separations, method development, quality control testing, and method transfer from Agilent Zorbax® C18 columns and similar USP L1 methods. This configuration remains one of the most popular Zx Similars C18 columns in the product line.

Key Benefits

• Type-B spherical silica stationary phase

• Suitable alternative for USP L1 methods

• Comparable selectivity to Agilent Zorbax® C18 columns

• Balanced resolution and analysis time

• Broad compatibility with conventional HPLC systems

• Lower operating pressure than smaller particle columns

• Strong hydrophobic retention

• One of the most popular Zx Similars C18 column configurations

Typical Applications

• USP L1 methods

• Reversed-phase HPLC

• Pharmaceutical analysis

• Quality control testing

• Method development

• Long-chain fatty acid analysis

• Routine analytical separations

• Method transfer and validation

Specifications

• Product Type: HPLC Column

• Stationary Phase: Zx Similars C18

• USP Classification: L1

• Particle Size: 5 µm

• Particle Type: Type-B Spherical Silica

• Bonded Phase: C18 (Octadecyl)

• Endcapped: Yes

• Column Dimensions: 4.6 mm ID x 150 mm

• Length: 150 mm

• Recommended Flow Rate: 1.0–2.0 mL/min

• Brand: Cogent

Important Notes

• Designed for reversed-phase chromatography

• 150 mm length balances resolution and analysis time

• Compatible with conventional HPLC systems

• Lower operating pressure than smaller particle columns

• Excellent alternative for many USP L1 methods

• Strong retention for hydrophobic compounds

• One of the most popular Zx Similars C18 column configurations

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