Fast and Accurate Determination of Arsenobetaine (AsB) in Fish Tissues Using HPLC-ICP-MS

Importance of the topic

Arsenic speciation is essential because toxicity varies with chemical form. Arsenobetaine (AsB) is the predominant non-toxic arsenic species in marine organisms. Reliable, high-throughput methods are needed to assess AsB in fish to distinguish safe from toxic samples.

Objectives and study overview

This work aims to develop and validate a semi-automated method combining accelerated solvent extraction (ASE) and high-performance liquid chromatography coupled to inductively coupled plasma mass spectrometry (HPLC-ICP-MS) for rapid, accurate determination of arsenic species, particularly AsB, in fish tissues.

Methodology and instrumentation

Key steps:

• Sample extraction: Dionex ASE 200 at 100 °C, 1500 psi, methanol solvent, 5 × 2 min cycles, processing up to 24 samples automatically.
• Chromatography: Hamilton PRP X-100 anion exchange column; isocratic elution with 2.2 mM NH4HCO3 + 2.5 mM tartaric acid, 1% MeOH (pH 8.2), 1 mL/min; 10 min run separates 4–6 species.
• Detection: Agilent 1100 HPLC coupled to Agilent 7500i ICP-MS; tuned daily for As sensitivity; internal standard 103Rh monitored.
• Calibration: external calibration validated against standard addition; detection limit for AsB of 0.04 ng/g as As.

Main results and discussion

• Separation of AsB, As(III), DMA, MMAA within 10 min with baseline resolution.
• Organic matrix effects from methanol elution caused plasma signal fluctuations, mitigated by 10× dilution of extracts.
• No significant difference between external calibration and standard additions, indicating minor matrix interference.
• Linear response over 0–700 ng/g As with R2 ≥ 0.999.

Benefits and practical applications

The method offers rapid analysis (over 50 injections / 12 h), minimal sample preparation (dilution only post-ASE), and high throughput for toxicological screening of seafood by quantifying the nontoxic AsB proportion.

Future trends and potential applications

Further integration of post-column organic modifiers may enhance sensitivity for less responsive species. Automation of data processing and coupling with alternative column chemistries could expand speciation to other organoarsenic compounds in diverse matrices.

Conclusion

A robust, validated ASE–HPLC-ICP-MS method enables fast, accurate, and high-throughput determination of arsenobetaine and other arsenic species in fish tissues, supporting comprehensive toxicological risk assessment in seafood monitoring.

References

The summary is based on the following key references from the original application:

• R. Wahlen et al., Foods, 2003.
• S. Branch et al., J. Anal. At. Spectrom., 1994.
• U. Kohlmeyer et al., Rapid Commun. Mass Spectrom., 2002.