1. TESLA (Trace Element Speciation Laboratory), Chemistry Department, University of Aberdeen, Aberdeen, AB24 3UE, United Kingdom
2. Institute of Biological and Environmental Sciences, University of Aberdeen, Cruickshank Building, St Machar Drive, Aberdeen, AB24 3UU, United Kingdom
3. Winston-Salem State University, 601 Martin Luther King Jr. Drive, Winston Salem, North Carolina 27110, United States
4. ACES (Aberdeen Centre for Environmental Sustainability), University of Aberdeen, St Machar Drive, Aberdeen, AB24 3UU, United Kingdom