Ultrafast Analysis of Aldehydes and Ketones

Importance of the Topic

Volatile aldehydes and ketones are key environmental pollutants and biomarkers in food, air quality and industrial processes. Their accurate quantification at trace levels requires stable, high-throughput methods. Derivatization with 2,4-dinitrophenylhydrazine (DNPH) followed by reversed-phase HPLC is widely adopted. Recent advances in ultrafast gradient technology offer markedly reduced analysis times while preserving resolution and reproducibility.

Objectives and Study Overview

This study demonstrates two ultrafast HPLC methods for separating 13 DNPH derivatives of common aldehydes and ketones using a Shimadzu Nexera system. The goals were to assess separation speed, peak reproducibility and suitability for routine environmental and quality-control laboratories.

Methodology and Instrumentation

Both methods derivatize analytes with DNPH and employ a Phenomenex Kinetex C18 core-shell column (50 mm × 3.0 mm I.D., 2.6 µm) or (50 mm × 2.0 mm I.D., 2.6 µm). Key parameters include:

• Binary gradient elution: mobile phase A (water/THF 8 : 2) and B (acetonitrile), flow 1.5 mL/min, column temp 50 °C, injection 5 µL, UV detection at 360 nm.
• Ternary gradient elution: mobile phases A (water), B (acetonitrile), C (THF), flow 0.9 mL/min, column temp 50 °C, injection 2 µL, UV detection at 360 nm.
• Nexera high-pressure gradient pumps and a 180 µL mixer ensure rapid mixing and accurate solvent delivery.

Main Results and Discussion

The binary method achieved baseline resolution of all 13 derivatives within 4 minutes. For formaldehyde-DNPH, retention time RSD was 0.087% and peak area RSD 0.16% (n=6), demonstrating excellent repeatability. The ternary method reduced total run time to approximately 2.5 minutes while maintaining adequate separation, illustrating the flexibility of a three-solvent gradient.

Benefits and Practical Applications

• High throughput: enables large sample batches in minimal time.
• Reproducibility: low RSD values support reliable quantitation in QA/QC.
• Versatility: binary and ternary gradients accommodate different matrix complexities.

Future Trends and Potential Applications

Future developments may include coupling ultrafast gradients with mass spectrometry for enhanced selectivity, greener solvents to reduce environmental impact, on-line derivatization and automation for real-time monitoring. Miniaturized UHPLC and multipath mixers could further boost speed and sensitivity.

Conclusion

The Nexera ultrafast gradient platform, paired with a high-efficiency core-shell column, provides a robust solution for rapid separation of DNPH-derivatized aldehydes and ketones. Laboratories benefit from shortened run times, high reproducibility and flexible gradient options.

References

• Shimadzu Corporation. Nexera Application Data Sheet No.13, LAAN-J-LC-E090. March 2011.