LC-MS Analysis of Compounds Related to Nucleic Acids

Significance of the Topic

Nucleic acids are fundamental to genetic information and cellular functions. Free nucleobases and nucleosides play crucial roles in metabolism and can indicate physiological or pathological states. Elevated uric acid, a purine metabolite, is linked to gout and metabolic disorders, highlighting the need for sensitive analytical methods to monitor these compounds in biological fluids and food products.

Objectives and Study Overview

This study demonstrates the application of liquid chromatography–mass spectrometry (LC-MS) for simultaneous separation, detection, and identification of nucleic acid–related compounds. The primary goals were to achieve high sensitivity, reliable molecular weight confirmation, and effective analysis of both standards and complex matrices such as beer.

Methodology and Instrumentation

• Chromatography: reversed-phase L-column ODS (150 mm × 2.1 mm I.D.), gradient elution from 1 % to 80 % acetonitrile in 0.1 % acetic acid over 30 min, flow rate 0.2 mL/min, column temperature 30 °C, injection volume 3 μL.
• Mass Spectrometry: electrospray ionization in positive mode (+4.5 kV), CDL and block heater at 200 °C, nebulizing gas 1.5 L/min, drying gas pressure 0.1 MPa, selected ion monitoring of m/z 136, 137, 152, 153, 169, 228, 252, 268, 269, and 284.

Main Results and Discussion

Positive ESI-MS spectra of adenine and adenosine exhibited distinct [M+H]+ signals at m/z 136 and 268, respectively, confirming molecular identities. The SIM chromatogram achieved baseline separation of 15 nucleobases and nucleosides. In beer samples, xanthine and guanosine were detected in a regular brew but absent in a low-purine variant, demonstrating the method’s effectiveness for food quality assessment.

Benefits and Practical Applications

The described LC-MS approach provides:

• High sensitivity and specificity for nucleic acid components.
• Molecular weight confirmation via ESI-MS spectra.
• Applicability to biological fluids for clinical diagnostics.
• Capability to evaluate purine content in food and beverages for nutritional studies and quality control.

Future Trends and Applications

• Extension to nucleotide and modified nucleoside analysis.
• Integration with tandem MS for enhanced structural elucidation.
• High-throughput platforms for clinical and industrial laboratories.
• Development of portable LC-MS systems for on-site analysis.

Conclusion

LC-ESI-MS with selected ion monitoring offers a robust, sensitive, and versatile platform for comprehensive analysis of nucleic acid-related compounds in diverse matrices, supporting research, clinical diagnostics, and food quality control.

References

• Shimadzu Application News No. C37: LC-MS Analysis of Compounds Related to Nucleic Acids, Shimadzu Corporation, 2010.