Blood and urine samples
The laboratory staff volunteered blood and urine samples for the
experimental studies and application of the methodology. Eleven
whole blood and urine samples were obtained from male and female
adults not occupationally exposed and selected randomly.
The accuracy of the procedures was checked using reference samples.
In the absence ofwhole blood reference materials, a serum sample was
used as control (Contox I Serum, lot TM144-1097, Kaulson Laboratories,
USA), with a tin concentration of 3±2 μg L−1. On the other hand, a reference
sample of urine (Seronorm Urine, lot 0511545, Sero AS, Norway)
at a concentration of 54.6±2.7 μg L−1 was used for controlling the urine.
Reference samples were reconstituted according to the manufacturer's
instructions and pre-treated as described in Sample preparation section