Varian SPEC Plus Columns 3 ml 6 Packs of 10 Columns Each

Varian / Agilent Bond Elut SPEC C18AR Solid Phase Extraction (SPE) Cartridges – 15 mg Sorbent Mass, 3 mL Column Volume, Monolithic Glass Fiber Disk Technology, 100/Pack (MPN: A5321920)

The Varian A5321920 (now cataloged under Agilent Technologies as Bond Elut SPEC C18AR, MPN: A5321920) is a high-performance, 3 mL Solid Phase Extraction (SPE) column designed for rapid, reproducible sample cleanup and analyte enrichment in bioanalytical, pharmaceutical, and clinical LC-MS/MS workflows. Engineered with SPEC micro-disk technology, this column features a 15 mg octadecylsilane (C18AR / Acid Resistant) sorbent bed embedded within a uniform monolithic glass fiber disk. Unlike traditional loose-packed silica SPE cartridges, the SPEC disk eliminates particle channeling, prevents silica fines from entering the eluate, and drastically reduces void volume. The result is ultra-low elution volume requirements, fast flow rates under vacuum or pressure, and exceptional analyte recovery from complex biological matrices like plasma, serum, and urine.

Technical Performance and Monolithic Disk Engineering

• Monolithic Glass Fiber Micro-Disk Design: Infuses the octadecylsilane (C18) stationary phase into a porous glass fiber matrix. This structure prevents bed disruption, particle channeling, and drying issues, delivering consistent flow rates and uniform extraction kinetics.

• Acid-Resistant C18AR Surface Chemistry: Specially modified hydrophobic C18 bonded phase designed to retain non-polar organic molecules, metabolites, and drug candidates while withstanding acidic pre-treatment protocols without phase stripping.

• Ultra-Low Elution Volume Capability: The low void volume of the 15 mg SPEC disk allows analytes to be eluted in micro-volumes (as low as 100 to 200 microliters), enabling direct LC-MS/MS injection or significantly shortening blow-down evaporation cycles.

• Elimination of Fines & Column Plugging: Because the sorbent matrix is bound within the fiberglass disk, no particulate fines wash out into final extracts, protecting analytical HPLC/UHPLC columns and mass spec sources from clogging.

Product Specifications

• Part Number / MPN: A5321920 (Cross-listed as Varian A5321920 / Agilent Bond Elut SPEC A5321920)

• Manufacturer / Brand: Varian, Inc. / Agilent Technologies

• Sorbent Chemistry: SPEC C18AR (Acid-Resistant Octadecylsilane, Reversed-Phase)

• Sorbent Mass: 15 mg per cartridge

• Column Volume: 3 mL standard barrel

• Housing Material: Ultra-clean, medical-grade Polypropylene (PP)

• Packaging Quantity: Box of 100 individual cartridges

• Manifold Interoperability: Fits standard SPE vacuum manifolds, positive pressure processors (such as Agilent PPM-48), and automated SPE liquid handlers

Key Benefits and Applications

• High-Sensitivity Bioanalysis & Pharmacokinetics: Essential for extracting low-concentration pharmaceuticals, metabolites, and biomarkers from whole blood, serum, plasma, and tissue homogenates.

• Toxicology & Clinical Screening: Provides fast, clean extraction of drugs of abuse, therapeutic agents, and steroid panels prior to quantitative LC-MS/MS or GC-MS runs.

• Streamlined Solvent Usage: Decreases hazardous organic solvent consumption during wash and elution steps, lowering operational costs and waste disposal overhead.

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