Catalog Number - 65318-15P

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.

65318-15P is a 150 mm x 4.6 mm ID analytical column packed with 3 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 3 µm particle size delivers higher efficiency and improved peak capacity compared to traditional 5 µm columns while generating increased operating pressure that should be considered during method development. Typical operating flow rates are approximately 1.0–2.0 mL/min on HPLC systems capable of supporting elevated backpressure.

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.

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

• Higher efficiency than comparable 5 µm columns

• Strong hydrophobic retention

• Excellent for hydrophobic and neutral compounds

• End-capped C18 bonded phase

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: 3 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

• Higher efficiency than comparable 5 µm columns

• Increased operating pressure compared to larger particle sizes

• Compatible with HPLC systems capable of handling elevated backpressure

• Excellent alternative for many USP L1 methods

• Strong retention for hydrophobic compounds

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