Analysis of Trace Elements in Whisky Using the Thermo Scientific iCAP 7000 Plus Series ICP-OES

Importance of the Topic

Monitoring trace elements in whisky is essential to ensure product quality, consumer safety and regulatory compliance. Copper equipment used during distillation can leach metals such as arsenic, while raw materials and water may introduce additional contaminants. Sensitive elemental analysis methods are required to detect and quantify both toxic and nutrient elements in alcoholic beverages.

Objectives and Study Overview

The study aimed to:

• Demonstrate the capability of the Thermo Scientific iCAP 7000 Plus Series ICP-OES Duo to analyze trace and major elements in whisky
• Validate the method for a range of spirits with similar alcohol content
• Assess accuracy through spike recovery and compliance with regulatory limits

Instrumentation Used

• Thermo Scientific iCAP 7600 Plus Series ICP-OES Duo equipped with an organics sample introduction kit (cyclonic spray chamber, V-groove nebulizer)
• Teledyne CETAC ASX-560 autosampler
• Qtegra Intelligent Scientific Data Solution (ISDS) software for data acquisition and processing

Methodology

Calibration standards and spike solutions were prepared in 0.2% nitric acid with 40% ethanol and fortified with yttrium as an internal standard. Five whiskies (two single malts and three Irish whiskeys) were analyzed. Instrument optimization included torch alignment and spectral calibration. Interference-free wavelengths were selected, and method detection limits were determined from multiple blank replicates.

Main Results and Discussion

Detection limits for most elements were in the low single-digit μg/L range, with arsenic and lead at 30 μg/L and 33 μg/L, respectively. Spike recoveries for trace elements fell within ±20%, confirming method accuracy. All measured toxic metals (As, Cd, Pb) were below regulatory maximum concentrations. The dual viewing modes allowed robust analysis despite the organic matrix.

Benefits and Practical Applications

This ICP-OES method provides fast, reliable testing for beverage manufacturers and quality control laboratories. It supports compliance with European regulations and offers high throughput for routine monitoring of spirits.

Future Trends and Applications

Opportunities include integrating speciation analysis, expanding element panels, enhancing automation and interfacing with sample preparation robotics to increase throughput and applicability to a wider range of complex matrices.

Conclusion

The Thermo Scientific iCAP 7600 Plus Series ICP-OES Duo demonstrates excellent sensitivity, accuracy and robustness for trace and major element analysis in whisky, making it a valuable tool for beverage quality assurance.