High Throughput Analysis of Animal Feed using the Agilent 7800 ICP-MS with ISIS 3

Significance of the Topic

A rapid and reliable multi-element analysis of animal feed is critical for ensuring livestock health, consumer safety, and compliance with regulatory standards. Monitoring nutrient elements and potential contaminants in feed supports informed feed selection, quality assurance, and adherence to the EN 17053:2018 standard for trace and heavy metals.

Objectives and Study Overview

This study demonstrates a high-throughput method for the simultaneous determination of 25 elements in animal feed using the Agilent 7800 ICP-MS equipped with ISIS 3. The method aims to exceed the performance requirements of EN 17053:2018 for 13 regulated elements while extending coverage to additional nutrients and minor elements.

Methodology

A single microwave digestion workflow was applied to diverse feed matrices, followed by ICP-MS analysis under high matrix conditions. Key steps included:

• Sample types: certified reference materials (rye grass, maize, lucerne) and real feeds (chicken grain mix, rabbit grass).
• Microwave digestion of 0.20 g subsamples with HNO₃/HCl and dilution to 50 mL.
• Calibration using multi-element standards covering nutrients (Ca, K, Mg, Na, P, S), minors (Al, B, Cr, Ni, Sr, V) and traces (As, Cd, Co, Cu, Fe, Hg, Mn, Mo, Pb, Se, Tl, U, Zn).
• Use of high matrix introduction (HMI) to handle up to 3 % total dissolved solids and ORS4 helium collision mode to remove polyatomic interferences.
• Integrated Sample Introduction System (ISIS 3) for rapid discrete sample uptake, rinse, and measurement.

Instrumental Setup

• Agilent 7800 ICP-MS with High Matrix Introduction and ORS4 collision/reaction cell in helium mode.
• ISIS 3 discrete sampling device and SPS 4 autosampler for fast loop filling and probe rinsing.
• MicroMist concentric nebulizer, quartz Scott-type spray chamber, quartz torch with 2.5 mm injector, and nickel interface cones.

Main Results and Discussion

Calibration linearity exceeded R² > 0.9999 across the full concentration ranges (Ca up to 500 ppm; As/Cd to 1000 ppb; Hg to 2 ppb). Method detection limits and quantitation limits were well below EN 17053:2018 thresholds for all elements.

Stability tests over nine hours (266 injections) yielded internal standard recoveries within ±20% and continuing calibration verification within ±10%, demonstrating robust plasma performance under high matrix loads.

Accuracy assessments via certified reference materials produced recoveries within ±10% (±15% for select elements), and spike recoveries in real feed samples remained within ±10% over a dynamic range from sub-ppb to hundreds of ppm.

The average sample-to-sample time was 122 s, supporting high sample throughput without compromising data quality.

Advantages and Practical Applications of the Method

• Comprehensive simultaneous quantitation of nutrients, minor, and trace contaminants.
• High throughput through rapid discrete sampling and minimal manual dilution.
• Enhanced matrix tolerance via HMI and helium collision mode, reducing interface fouling.
• Full compliance with EN 17053:2018 and extended analytical scope.
• Ideal for routine QA/QC workflows in feed testing and agricultural laboratories.

Future Trends and Potential Applications

Future developments will focus on deeper automation, integration with laboratory information management systems, expansion to emerging contaminants, and adaptation to other complex food and environmental matrices. Advances in cell technology and sampling hardware will further reduce analysis times and improve detection capabilities.

Conclusion

The Agilent 7800 ICP-MS with HMI and ISIS 3 enables accurate, sensitive, and high-throughput multi-element analysis of animal feed. It surpasses EN 17053:2018 performance requirements, offering streamlined sample preparation, sustained instrument stability, and the ability to quantify a broad range of analytes in a single analytical run.

References

1. European Committee for Standardization. EN 17053:2018 Animal feeding stuffs—Methods of sampling and analysis—Determination of trace elements, heavy metals and other elements in feed by ICP-MS.
2. Agilent Technologies. Plasma Robustness in ICP-MS: Benefits of a Low CeO/Ce Ratio. Publication 5990-8060EN.
3. Agilent Technologies. ORS4 and Helium Mode for More Effective Interference Removal in Complex Samples. Publication 5990-7574EN.
4. Agilent Technologies. Critical Factors Affecting Cost-of-Ownership of ICP-MS. Publication 5991-9342EN.