Analysis of aflatoxins using LCMS-2010A

Significance of Aflatoxin Analysis

Aflatoxins are potent, naturally occurring toxins produced by Aspergillus molds on staple crops such as peanuts and corn. Their strong carcinogenicity and strict regulatory limits (10 ppb in Japan) make sensitive, reliable detection essential for food safety and public health.

Objectives and Study Overview

This application note describes an LC-MS protocol using the Shimadzu LCMS-2010A to quantify four major aflatoxin congeners (G2, G1, B2 and B1) in accordance with Japanese official methods. The goal is to achieve low-level detection (0.5–2.5 ppb) with high precision and linearity.

Methodology and Instrumentation

The separation and detection parameters were optimized for sensitivity and reproducibility. Key analytical conditions include:

• Column: Imtakt Cadenza CD-C18 (2.0 mm × 150 mm), 40 °C
• Mobile Phase A: acetonitrile/methanol/10 mM ammonium acetate (2 / 6 / 15), flow rate 0.2 mL/min
• Injection Volume: 6 µL
• Ionization: ESI-positive, probe voltage 4.5 kV; CDL 300 °C; BH 250 °C
• Gas Flows: nebulizing 1.5 L/min; drying 0.15 MPa
• Scan Range: m/z 200–400; SIM channels: m/z 331.1, 329.1, 315.1, 313.0 (0.25 s/channel)

Main Results and Discussion

SIM chromatograms at 2.5 ppb yielded signal-to-noise ratios between 203 and 557 for the four toxins, while 0.5 ppb standards produced S/N values from 43 to 84. Mass spectra confirmed [M+H]+ ions at expected m/z values. Calibration curves covering 0.5–100 ppb (n=5) exhibited excellent linearity (r2 ≥ 0.9999), demonstrating reliable quantification over a wide dynamic range.

Benefits and Practical Applications

The described LC-MS method offers:

• High sensitivity suitable for regulatory compliance and routine monitoring
• Elimination of hazardous reagents previously used in aflatoxin assays
• Robust performance for QA/QC in food safety laboratories

Future Trends and Possibilities

Advancements may include faster ultra-high-performance LC separations, simultaneous multi-mycotoxin screening, coupling with high-resolution MS for structural confirmation, and integration of data analytics for enhanced throughput and decision support.

Conclusion

The Shimadzu LCMS-2010A method provides a streamlined, sensitive, and reproducible approach for aflatoxin quantification, meeting stringent regulatory requirements and supporting effective food safety surveillance.

References

• Japanese Ministry of Health, Labor and Welfare. Official aflatoxin testing methods, 1971.
• Food Sanitation Law, Japan. Revised aflatoxin testing methods, 2002.
• Shimadzu Corporation. LC-MS Application Data Sheet No. 050: Analysis of aflatoxins using LCMS-2010A.