Atomic absorption spectrophotometric determination of liver copper: collaborative study.

Area of Science:

• Analytical Chemistry
• Food Science
• Veterinary Medicine

Background:

• Accurate quantification of essential trace elements like copper in food matrices is crucial for both nutritional assessment and regulatory compliance.
• Existing methods for copper determination in biological tissues may lack the necessary precision or sensitivity for comprehensive analysis.
• The need for a standardized, reliable method for copper analysis in bovine liver was identified.

Purpose of the Study:

• To collaboratively validate a novel analytical method for determining copper concentrations in bovine liver samples.
• To assess the method's accuracy, precision, and limit of detection across multiple independent laboratories.
• To establish a robust and officially recognized procedure for copper analysis in bovine liver.

Main Methods:

• Collaborative study involving eleven laboratories analyzing blind duplicate bovine liver samples.
• Samples were either naturally copper-rich or spiked to cover a range of copper levels.
• Method involved acid digestion (concentrated HNO3), dilution, and analysis via atomic absorption spectrophotometry (AAS).

Main Results:

• Intralaboratory coefficients of variation (CVo) ranged from 5.6% to 19%.
• Interlaboratory coefficients of variation (CVx) ranged from 7.1% to 21%.
• The method's lower limit of detection was determined to be approximately 1 mg copper/kg tissue.

Conclusions:

• The validated atomic absorption spectrophotometry method provides reliable and reproducible results for copper determination in bovine liver.
• The method's performance across multiple laboratories supports its suitability for routine analysis.
• The method has been officially adopted for first action use, indicating its acceptance for regulatory purposes.