TORAST-H Vial Series - Shimadzu Original Low Adsorption Vial

Significance of the Topic

The adsorption of analytes onto vial surfaces can compromise quantitative accuracy, reproducibility and sample integrity in trace-level analysis. Low-adsorption containers are critical in pharmaceutical, environmental and bioanalytical workflows to preserve sample concentration over time and minimize losses of basic, acidic or neutral compounds.

Objectives and Overview of the Note

This application note introduces the TORAST-H Vial Series by Shimadzu, designed to suppress adsorption through advanced glass and polymer treatments. It evaluates adsorption performance across compound classes, assesses long-term storage stability and presents formats optimised for small-volume sampling and peptide analysis.

Methodology and Material Treatment

The TORAST-H Glass Technology employs a proprietary leaching process to remove surface metal oxides and generate a fused quartz-like SiO2 layer, reducing ionic and hydrophobic interactions. Adsorption tests were conducted with representative basic (amitriptyline, log P 4.5 pKa 10.5), acidic (benzoic acid) and neutral (benzyl alcohol) compounds. Recovery was monitored by UV detection over standard injection gradients. Long-term storage adsorption was measured at intervals up to three months. A small-volume vial design with concave bottom minimizes liquid contact area and thermal mass.

Main Results and Discussion

TORAST-H glass vials yielded >99% recovery for basic, acidic and neutral analytes compared to significant losses in untreated containers. Long-term storage tests demonstrated consistent analyte recovery (>95%) after one month and maintained integrity over three months. Small-volume inserts showed markedly reduced concentration gradients versus standard inserts. The TORAST-H Bio Vial, made of treated polypropylene, delivered near-complete recovery of peptides (100%) versus 52–81% in conventional glass or PP vials. A 96-well polypropylene plate version also exhibited low adsorption of organic compounds.

Benefits and Practical Applications

Using TORAST-H vials enhances analytical precision by:

• Preventing surface adsorption losses across compound classes
• Improving long-term sample stability for QC and pharmacokinetic studies
• Optimising low-volume workflows and high-throughput formats for peptides and basic pharmaceuticals

Future Trends and Potential Uses

Advancements in surface engineering may extend low-adsorption coatings to diverse polymeric plates and microfluidic devices. Integration with automated sample-handling systems and expansion into biotherapeutic assays will further reduce assay variability. Emerging techniques like nanocoatings or dynamic surface charge modulation could deliver next-generation vials with tailored selectivity and ultra-low adsorption profiles.

Conclusion

The TORAST-H Vial Series provides a robust solution for minimizing adsorption in analytical workflows. Its glass and bio-grade polypropylene formats offer consistent recovery, long-term stability and suitability for small-volume and high-throughput applications, ensuring reliable data integrity in demanding laboratories.