Application of ICP-MS to Examining the Utility of Skin as a Monitoring Tissue for Trace Elements in Bottlenose Dolphin, Tursiops Truncatus

Abstract

Collision cell technology inductively coupled plasma mass spectrometry (CCT-ICP-MS) was applied to answer fundamental questions about the utility of bottlenose dolphin skin as a monitoring tissue for trace element concentrations. Bottlenose dolphin skin samples were obtained from two freshly dead animals during necropsies. The samples were collected from twelve standardized locations across each animal, representing a significant spatial surface area to test among site trace element concentration variability. Skin biopsy samples were analyzed for As, Cd, Cu, Mn, Mo, Pb, Rb, Se, Sr, V and Zn concentrations by CCT-ICP-MS, and Hg concentrations were separately measured by atomic fluorescence spectrometry (AFS). Wet mass concentrations ranged from > 100 μg/g (Zn) to < 0.0100 μg/g (V, Mo, Cd, and Pb). Relative standard deviations of less than 20% among sample sites were observed for Cu, As, Se, and Hg, demonstrating that deposition of these elements may be tightly regulated in skin tissue. Multifactor mixed-effect analysis of variance analyses (ANOVA) showed significant effects (p < 0.05) longitudinally (dorsal-ventral) for Cu, Mo, Ru, Se, V, and Zn indicating that standardized sample collection sites may be needed for comparative evaluation of these elements between animals, due to relatively heterogeneous distribution in skin.