Fast and sensitive assay of tobacco specific nitrosamines by UHPLC-MS/MS

Importance of the topic

Tobacco specific nitrosamines (TSNAs) are potent carcinogens formed during the processing and consumption of tobacco products. Accurate monitoring of NNN, NAT, NAB, and NNK is critical in tobacco quality control and environmental exposure assessments.

Objectives and overview of the study

This study aimed to develop a rapid, sensitive, and robust UHPLC-MS/MS method for quantifying major TSNAs in tobacco samples with minimal matrix interference and high throughput.

Methodology and instrumentation

A selective solid phase extraction using molecularly imprinted polymers (Biotage AFFINILUTE MIP – TSNAs) isolated TSNAs from 250 mg tobacco samples spiked with deuterated internal standards (NNN-D4, NAT-D4, NAB-D4, NNK-D4). Eluates were reconstituted in mobile phase and analyzed by UHPLC (Shimadzu Nexera MP) on a Phenomenex Synergi Fusion-RP C18 column (50 × 2 mm, 2.5 µm). The LC gradient employed 5 mM ammonium bicarbonate in water and methanol at 0.4 mL/min. Detection was performed on an LCMS-8040 triple quadrupole in positive ESI-MRM mode with optimized transitions for each TSNA and its internal standard.

Main results and discussion

Mobile phase optimization identified 5 mM ammonium bicarbonate with methanol as optimal for ionization efficiency. Extraction recoveries ranged from 70% to 96% across TSNAs, with ionization recoveries between 95% and 107%, indicating negligible matrix effects. Calibration was linear from 0.1 to 50 ng/mL (R2 > 0.999) with intra-level precision (%RSD) below 5%. The method achieved a LOQ of 0.1 ng/mL, corresponding to 0.004 µg/g in tobacco.

Benefits and practical applications of the method

The selective SPE and fast UHPLC-MS/MS workflow deliver high specificity and sensitivity while minimizing ion suppression. The approach supports high sample throughput for routine quality control of tobacco raw materials and finished products and can be extended to smoke analysis.

Future trends and potential applications

Integration of automated online sample preparation could further streamline analysis. Advances in high-resolution MS may enable simultaneous screening of emerging nitrosamine analogs. The method could support regulatory compliance monitoring and risk assessment of novel tobacco products.

Conclusion

A fast and sensitive UHPLC-MS/MS assay for TSNAs has been established, offering robust quantitation, minimal matrix effect, and high throughput suitable for quality control and research.

References

• 60th ASMS, ThP512