Cut segments of hair about 5 to 10 mm in length and weighing at least
10 mg. Treat each segment separately. Weigh each segment and wash in
deionized water on a mechanical shaker and then boil. Transfer the
sample to a 100-mL Teflon beaker and digest with a 1:5 mixture of
HClO4
: HNO3
until only a few drops of clear liquid remain. Dilute the
sample 1:50 with deionized water.