Simultaneous Determination of Heavy Metal and Mineral Contents in Fruit Juices using Inductively Coupled Plasma Mass Spectrometry

Significance of the Topic

The growing consumption of fruit juices highlights the need to monitor heavy metal and mineral levels for food safety. Ensuring compliance with international guidelines protects public health and supports quality control in the beverage industry.

Objectives and Study Overview

This work aimed to develop a rapid, sensitive, and reliable method for simultaneous quantification of 15 elements in fruit juices. Results were compared with WHO and US EPA drinking water limits to assess potential health risks.

Applied Methodology

Sample Preparation:

• Four commercial juices (apple, yuzu, mango, guava) were homogenized and subjected to closed-vessel microwave digestion using concentrated nitric acid and hydrogen peroxide.
• Digestion protocol included a ramp to 180°C, hold, and cooldown steps, followed by dilution to a total factor of 20.

Quantitative Analysis:

• External calibration (0.5–40 µg/L) with internal standards (Ho, Rh, Y) at 2.5 µg/L.
• Helium collision cell mode applied to remove polyatomic interferences and improve detection limits.

Used Instrumentation

• Shimadzu ICPMS-2030 equipped with mini-torch and cyclone chamber at 5 °C.
• Operating parameters: RF power 1.2 kW, Ar plasma gas 8.0 L/min, auxiliary gas 1.10 L/min, carrier gas 0.70 L/min, He cell gas 6.0 mL/min.

Main Results and Discussion

Calibration curves for all elements exhibited excellent linearity (r > 0.9996). Method detection limits ranged from 0.000 to 0.056 µg/L.

• Element concentrations in all juices were well below WHO/EPA limits or not detected. Arsenic was highest in apple juice (1.49 µg/L) but under the 10 µg/L threshold.
• Cadmium, lead, and other toxic metals were found at trace levels or absent, indicating minimal contamination.
• Spike recoveries (89–117%) and precision (%RSD < 2.5) demonstrated method accuracy and repeatability.
• Instrument stability over 5 h and day-to-day reproducibility (<20% variation) confirmed robust performance.

Benefits and Practical Applications

The developed ICP-MS protocol offers high throughput, low detection limits, and reliable quantification, making it suitable for routine QA/QC of beverages and compliance testing against regulatory standards.

Future Trends and Potential Applications

Advances may include on-line sample introduction, speciation analysis of toxic forms, miniaturized plasma sources, and integration with data analytics for real-time monitoring of food safety.

Conclusion

A validated microwave digestion–ICP-MS method was established for simultaneous multi-element analysis in fruit juices. The approach delivers accurate, sensitive, and stable measurements, ensuring compliance with health guidelines and supporting industrial quality assurance.

Reference

1. Dehelean A, Magdas DA. Analysis of Some Romanian Fruit Juices by ICP-MS. AIP Conf Proc. 1565:285, 2013.
2. World Health Organization. Guidelines for Drinking-water Quality, 4th ed. 2017.
3. US Environmental Protection Agency. National Primary Drinking Water Regulations. 2018.