A novel automated 2D-LCMS-IT-TOF system compatible with non-volatile salts applied to accelerating impurity ID workflow in chemistry, manufacturing and controls

Importance of the topic

Impurity identification in chemistry, manufacturing, and controls (CMC) is essential for ensuring product safety and regulatory compliance. High-resolution mass spectrometry methods must often accommodate nonvolatile salts used in optimized separations without losing analytical performance.

Objectives and overview

The study presents a fully automated two-dimensional LC–MS system combining ion-trap time-of-flight (IT-TOF) detection with a Co-Sense fractionation module. Its aim is to streamline impurity analysis workflows by retaining nonvolatile buffer separations in the first dimension and transferring isolated peaks to a volatile buffer–compatible second dimension for high mass accuracy detection.

Methodology and instrumentation

• First-dimension separation: conventional HPLC using phosphate buffers (pH 2.6) or ion-pair reagents on Shim-pack VP-ODS columns (150 × 4.6 mm, 5 μm) at 1.0 mL/min.
• Peak trapping: time-programmed switching valves direct individual impurity fractions into 10 μL loops.
• Second-dimension separation: Shim-pack XR-ODS columns (75 × 2.0 mm, 2.2 μm) with 0.1 % formic acid/water and methanol gradient at 0.3 mL/min.
• Detection: integrated UV detector in second-dimension HPLC and high-resolution LCMS-IT-TOF (m/z 100–1000) with external calibration.
• Instrument: Co-Sense 2D-LC module with switching valves; Shimadzu LC–MS IT-TOF system.

Main results and discussion

• Phosphate buffer workflow: five sulfa drugs were separated in the first dimension and isolated. Second-dimension analysis correctly identified the main API (sulfadimethoxine) and four unknown impurities, yielding molecular formulas with <2 ppm error.
• Ion-pair chromatography: three sulfa compounds separated, isolated, and transferred. A divert valve and column washing step effectively removed strongly retained ion-pair reagents, enabling clean LCMS analysis of three impurity mimics.
• UV chromatogram comparison between sample and blank facilitated rapid impurity detection.

Benefits and practical applications

• Automates method translation from nonvolatile to volatile buffer systems, reducing manual labor and risk of missing impurities.
• Supports existing CMC test methods without re‐optimizing first-dimension separations.
• Combines UV screening with high mass accuracy structure elucidation, significantly expediting impurity ID workflows.

Future trends and potential applications

Further expansion of the 2D-LC–MS approach could include integration with artificial intelligence for data processing, miniaturized fractionation loops for reduced sample volumes, and compatibility with a wider range of nonvolatile reagents. Enhanced automation and multiplexing may support high-throughput CMC screening and real-time quality control.

Conclusion

The novel automated 2D-LC–MS IT-TOF system successfully bridges nonvolatile buffer separations with high-resolution MS detection, accelerating impurity identification in pharmaceutical development. Its robust design and integrated UV–MS workflow reduce analysis time and improve data confidence.

Reference

• ASMS 2011, MP119. Ichiro Hirano et al., Shimadzu Corporation.