New liquid chromatograph

Shimadzu has introduced the new Nexera XS inert, a bioinert and biocompatible ultra-high performance liquid chromatograph (UHPLC). The system has been designed to resolve the most common problems encountered in the analysis of biopharmaceuticals, such as the adsorption of target molecules to metal surfaces and corrosion due to mobile phases with high salt content and extreme pH conditions. The development of the Nexera XS inert was based on the results of cooperative research with Professor Yasushi Ishihama of the Graduate School of Pharmaceutical Sciences at Kyoto University (Japan Science and Technology Agency’s A-STEP project, 2017 to 2020).

The new UHPLC features a metal-free sample flow path that prevents unwanted interaction with biopolymers prone to adsorption onto exposed metal sites. By doing this, the Nexera XS inert achieves reduced sample loss and excellent peak shape for reproducibly high sensitivity and high-quality, reliable data. In addition, all wetted surfaces are prepared from corrosion-resistant materials, rendering them stable against mobile phase solvents containing high concentrations of salts or acids.

The product offers the same superior reliability, robustness and expandability as the other UHPLC systems in the Nexera series. It is particularly well-suited to the analysis of biopolymers such as antibodies, peptides and nucleic acid drugs.

In addition to the analytical intelligence features of the Nexera series, the Nexera XS inert system offers several new advantages.

Unconstrained recovery and sensitivity

In quantitative analysis of biomolecules, adsorption of the target compound to a metal surface can result in a dramatic decrease in sensitivity. The Nexera XS inert system consists of stainless-steel-casing-reinforced PEEK tubing (polyether ether ketone), a high-performance engineered polymer with mechanical and chemical resistance properties. It ensures a system pressure tolerance of >100 MPa while maintaining a bioinert flow path. The ceramic injection needle offers metal-free injections and minimized carryover. By preventing adsorption to metal surfaces, the Nexera XS inert system achieves much higher sensitivity and better reproducibility than a general-purpose UHPLC system.

Assured reliability and reproducibility

High salt conditions in the mobile phase can result in corrosion of stainless steel parts in standard UHPLC systems. In the Nexera XS inert system, the wetted surfaces are prepared from highly rust-resistant materials, while maintaining the high-efficiency flow-path (105 MPa). The system is unaffected by high salt content, ion pairing agents or extreme pH conditions, ensuring long-term stability and reliable data acquisition.

Clear resolution without restrictions

The system’s 105 MPa pressure resistance enables the use of long separation columns packed with small-sized particles to achieve ultra-high efficiency in a wide variety of applications. The newly developed PEEK-lined tubing comes with tool-free, finger-tightened fittings. These permit reliably connected columns to withstand a pressure of up to 105 MPa without creating any dead volume or risking damage by overtightening. All valves used in the Nexera XS inert system are designed to inhibit metal adsorption, allowing for worry-free switching between multiple columns for method development or for trap-and-elute analysis. The optional pHM-40 offers real-time measurement of the mobile phase pH during the course of the experiment to ensure accuracy and traceability, even when running a pH gradient, as used in ion-exchange chromatography.

Consumables ideal for analysing biopharmaceuticals

Analysing biopolymers such as proteins, peptides and nucleic acids requires columns with different separation modes. Especially for samples that are sensitive to metal ions, an optimum column that takes adsorption into consideration is required. The Shim-pack series of columns is ideal for the analysis of a wide variety of biopolymers. In addition, adsorption of target analytes in the sample vial can greatly affect the analysis and requires special attention. Shimadzu offers the TORAST-H Bio Vial, a low-adsorption PP vial, e.g., for peptide drug research, and TORAST-H low-adsorption glass vials as a general-purpose option.

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