Trace metal determination in animal tissues: an interlaboratory comparison

Area of Science:

• Environmental Science
• Analytical Chemistry
• Marine Biology

Background:

• Narwhal blubber is a crucial indicator of marine ecosystem health.
• Accurate quantification of trace elements (Cu, Cd, Zn, Pb, Hg, Se) in narwhal tissues is vital for ecological and toxicological assessments.

Purpose of the Study:

• To evaluate the interlaboratory precision of trace element analysis in narwhal liver and muscle.
• To compare the performance of various analytical techniques for heavy metal determination in marine mammals.

Main Methods:

• Two reference materials (narwhal liver and muscle) were analyzed by 13 laboratories.
• Techniques included atomic-absorption spectrometry, atomic-emission spectrometry (DC/ICP), anodic stripping voltammetry (ASV), neutron activation analysis (NAA), and gas chromatography.
• Analysis focused on copper (Cu), cadmium (Cd), zinc (Zn), lead (Pb), mercury (Hg), and selenium (Se).

Main Results:

• Coefficients of variation (CV) for Cu, Cd, Zn, and Hg in liver were generally low (2-5%).
• Precision was poorer for Zn by ASV and NAA, and for Cu and Cd in muscle tissue (up to 19%).
• Lead (Pb) analysis showed overall precision of 15% (liver) and 21% (muscle). Selenium (Se) determination was precise (6-7%) except by NAA (21-26%).

Conclusions:

• Interlaboratory variability in trace element analysis of narwhal tissues can be significant, particularly for certain elements and matrices.
• The choice of analytical method impacts the precision of heavy metal quantification in marine mammal tissues.
• Standardization of methods is recommended for reliable biomonitoring of Arctic marine fauna.