Determination of Cu, Fe, K, Mg, Mn, Na and Zn in Food Using AAS in Fast Sequential mode

Significance of the topic

Trace level determination of essential and potentially toxic elements in food matrices is critical for consumer safety, regulatory compliance and nutritional studies. High‐throughput, accurate multi‐element analysis supports food quality monitoring and reduces operational costs in laboratories processing large sample volumes.

Objectives and overview

This study aimed to develop a fast, robust method for quantifying seven elements (Cu, Mn, Fe, K, Na, Mg and Zn) in a wheat flour reference material using flame atomic absorption spectrometry (AAS). The goal was to achieve reliable results for up to 100 samples per day by automating standard and sample preparation, minimizing manual intervention and ensuring high precision.

Methods and instrumentation

Instrumentation used:

• Agilent AA 280FS flame atomic absorption spectrometer with Fast Sequential (FS) mode for rapid element switching
• PRecision Optimized Measurement Time (PROMT) function to adjust measurement time based on precision targets (1% RSD)
• Agilent SIPS 10 Sample Introduction Pump System for automated inline dilution and standard preparation
• Built‐in Hammer Gas Box to optimize flame stoichiometry per element
• Hollow cathode lamps for each element with specific wavelengths, lamp currents and slit widths adjusted in FS mode

Method highlights:

• One stock solution was used with SIPS 10 to generate five calibration standards per element
• Inline dilution of over‐range samples prevented reruns
• Instantaneous gas flow changes and a high‐speed wavelength drive enabled measurement of all seven elements in a single aspiration

Main results and discussion

Calibration curves exhibited excellent linearity with correlation coefficients exceeding 0.999 for all elements. Analysis of the wheat flour standard GBW08503b yielded recoveries ranging from 93% (Cu) to 109% (Na), demonstrating accuracy within acceptable limits.

Automation reduced errors associated with manual standard preparation and sample dilution. The PROMT feature decreased measurement time for higher concentration points, saving both time and gas.

Overall, the combined use of FS mode, PROMT and SIPS 10 increased workflow efficiency more than threefold and cut total analysis time by over 70%, enabling high‐throughput operation.

Benefits and practical application

The optimized AAS method delivers:

• Significant labor savings by automating repetitive tasks
• Consistent precision and accuracy across multiple elements
• Reduced sample and reagent consumption
• Minimized reruns through inline dilution of over‐range samples
• Scalability for routine high‐volume food testing laboratories

Future trends and possibilities

Emerging directions include integration of AAS systems with laboratory information management systems (LIMS) for seamless data handling, further miniaturization and multiplexing of sample introduction systems, and coupling with advanced chemometric tools or AI algorithms to optimize method parameters in real time.

Potential applications extend to monitoring trace metals in beverages, dairy, meat and environmental samples, as well as quality assurance in nutraceutical and fortified food production.

Conclusion

The combination of fast sequential AAS, precision-controlled measurement time and automated sample introduction provides a powerful solution for rapid, reliable multi-elemental analysis in food matrices. This approach enhances laboratory throughput, reduces operational costs and maintains stringent data quality requirements.

Reference

1. Sun Kaiqi (2021). Determination of Cu, Fe, K, Mg, Mn, Na and Zn in Food Using AAS in Fast Sequential Mode. Agilent Application Brief 5994-3162EN.