Arsenic Speciation Analysis in Apple Juice Using HPLC-ICP-MS

Significance of the Topic

Arsenic in food and beverages poses significant health concerns due to the varying toxicity of its chemical forms. Inorganic species, arsenite (As(III)) and arsenate (As(V)), are highly toxic and carcinogenic, while organic species such as monomethylarsonic acid (MMA), dimethylarsinic acid (DMA), and arsenobetaine are less harmful. Accurate speciation analysis in apple juice is essential to ensure consumer safety and meet regulatory guidelines.

Study Objectives and Overview

This work aimed to develop a rapid, reliable method for determining five arsenic species in commercial apple juice. Six different brands were analyzed to quantify total and individual species concentrations, assessing compliance with drinking water limits and dietary intake recommendations.

Methodology and Sample Preparation

A streamlined protocol was used to preserve species integrity: apple juice samples were sequentially filtered through Millex-LH and TOYOPAK ODS filters, then diluted twofold with ultrapure water. Four preparation blanks (deionized water, membrane filter, ODS filter, full method blank) confirmed no arsenic contamination during preparation.

Used Instrumentation

• Agilent 1290 Infinity HPLC system with binary pump, autosampler, and vacuum degasser
• Anion-exchange guard column (4.6 × 10 mm) and speciation column (4.6 × 250 mm) with polymethacrylate packing
• Agilent 8800 Triple Quadrupole ICP-MS (single quadrupole mode, m/z 75 detection)

Results and Discussion

Detection limits for the five arsenic species ranged from 10 to 22 ng/L, with linear calibration from 10 to 500 ng/L. All six juices contained measurable arsenic, but total concentrations did not exceed 5 µg/L—well below the 10 µg/L EPA drinking water limit. Inorganic arsenic (As(III)+As(V)) was under 3 µg/L in all samples and below 2 µg/L in five of the six. Spike recovery (n=7) demonstrated excellent reproducibility (retention time RSD <0.5%, concentration RSD <1.6%).

Benefits and Practical Applications

• The simple filtration and mild dilution protocol avoids harsh digestion, minimizing species interconversion and maintaining low detection limits.
• HPLC-ICP-QQQ provides sensitive, selective separation of arsenic species in complex juice matrices.
• High throughput and reproducibility support routine monitoring, quality control, and regulatory compliance in food safety laboratories.

Future Trends and Opportunities

Advances in triple quadrupole ICP-MS (e.g., Agilent 8900) are expected to further lower detection limits and background signals. Automation of sample preparation and data analysis will enhance throughput. Extending speciation approaches to other beverages and foods will improve dietary exposure assessments and risk management.

Conclusion

The developed HPLC-ICP-QQQ method effectively quantifies five arsenic species in apple juice at sub-µg/L levels. All tested juices comply with regulatory limits for total and inorganic arsenic, demonstrating the method’s robustness, sensitivity, and suitability for routine food safety analysis.

References

1. World Health Organization. Arsenic fact sheet, 2022.
2. C.K. Tanabe et al. Speciated arsenic analysis in wine using HPLC-ICP-QQQ, Agilent publication.
3. B. Yue et al. Rapid determination of five arsenic species in polished rice using HPLC-ICP-MS, Agilent publication.