Chromatography

High-Performance Liquid Chromatography (HPLC)

• Separation using reverse-phase (hydrophobic interactions), normal phase (hydrogen bonding), or ion exchange (acid-base interaction) adsorption chromatography.
• Identification and quantification of polymer additives.
• Impurity content (residual solvents, monomers, by-products).
• Deformulation of plastic and rubber compounds, coatings, adhesives, sealants, personal care products, etc.
• Determination of residual formaldehyde and other adehydes and ketones
• Assay for active pharmaceutical ingredients in controlled release formulations and drug delivery devices.
• Extractables and leachables testing for drug packaging and medical devices.

Above: Separation and quantitation of UV absorbers and antioxidants extracted from a polypropylene copolymer building material. The additives were separated on a C18 stationary phase using an acetonitrile water gradient. The detection wavelength was 225 nm.

Work We've Done

Identification and Quantification of Antioxidants and UV Stabilizers

• Polypropylene filled with glass fiber.

• Reverse-phase HPLC using C18 column, acetonitrile:water gradient.

• Peak identification using UV/vis photodiode array detector, retention time comparison with standards, correlation with Gas Chromatography/Mass Spectrometry (GC/MS) library search results.

• Oligomeric Hindered amine light stabilizers (HALS), are identified and quantified using a proprietary technique.

Quantification of a Blowing Agent

• Residual azodicarbonamide blowing agent was extracted from foamed polyethylene.

• A normal-phase HPLC method was developed using a silica gel column and hexane/isopropanol mobile phase with UV detection at 275 nm.

• A linear calibration was obtained.

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