New columns for LC-MS and 2D chromatography

Capillary or micro columns are used where increased sensitivity is required or where analyte availability is limited. The company offers a range of capillary/micro columns packed with the polymeric materials. Small pore 3µm particles and the wide pore 5µm particles are aimed at small molecule and biomolecule research.

Capillary columns with a 300µm internal diameter are best suited to sample sizes in the range pg to ng, and are used with flow rates around 4µl/min. Micro columns with an internal diameter of 1.0mm are designed for sample sizes in the range ng to mg, and typically operate at flow rates in the range 40µl/min.

A spokeswoman for Polymer Laboratories​ told DrugResearcher.com​: "We identified a gap in the market where there was a need for chemically stable HPLC materials that do not leach soluble/insoluble material."​

"Drug discovery wise, any high sensitivity application using LC-MS and ADME will find this product most effective."​

The capillary and micro chromatography columns are available packed with reversed phase (PLRP-S) and both strong and weak cation (PL-SCX, PL-WCX) and anion (PL-SAX, PL-WAX) wide pore exchange media.

Reversed phase PLRP-S is a styrene/divinylbenzene copolymer with an inherently hydrophobic surface. No bonded phase is required for reversed phase chromatography. These rigid macroporous particles can be coated/derivatized to give a range of functionalities, including weak and strong cation and anion exchangers.

A gigaporous 4000å range of reversed phase and ion exchange materials is also available. A small pore, high capacity, 100å PLRP-S material is also included in the range for small molecule or peptide analysis.

4000å gigaporous particles are ideal for applications requiring increased speed. The capacity of these materials is significantly higher than monoliths or solid particles, and does not decrease as the flow rate is increased, due to the open pore structure.

The spokeswoman added: "Materials currently being used are based on silica particles and therefore limited in the pH that can be used."​

"Our product has the advantage that all the rigid polymerics are pH stable 1-14 and can be used with HPLC elements or with aggressive solutions for dissolving the samples."​

Chromatography is a well-established and popular technique for the analysis and quantification of determining sample make up. Although reversed-phase chromatography is the most commonly used chromatographic method for the analysis of drugs in the pharmaceutical industry, ion chromatography serves as an alternative method for ionic species that is often used to provide confirmation for the analysis of drugs, including sulfa drugs.

Beckman-Coulter​ has recently introduced a unique, automated 2D liquid chromatography system called 2DPF. This purification system permits highly reproducible protein separations into over 1000 collected fractions.

The system relies on sequential fractionation by ion-exchange with elution with a pH gradient followed by hydrophobic liquid chromatography. Since 2DPF has more than ten times the capacity for protein loading than traditional columns it may permit better resolution and detection of low abundance proteins.

However, each 2D purification takes about a day to perform, and there may still be insufficient resolution of signalling proteins from structural proteins and metabolic enzymes for their detection.

The emergence of microfluidics-based technology for liquid chromatography/mass spectrometry (LC/MS), increasingly adopted by scientists in protein research and pharmaceutical applications to separate and identify biological compounds, the traditional LC columns seems to have its days numbered.

Agilent Technologies​ has recently launched a reusable polymer high-performance LC (HPLC) chip combines the sample enrichment and separation capability of a nanoflow LC system with the connections and spray tips used in electrospray mass spectrometry.