Ten microlitres of samples (or standard solutions) and 10 lL of
4mgmL1 of calcium diluted from stock calcium nitrate solution
were pipetted into the graphite tube. Determination of fluorine
was performed via the rotational molecular absorption line of
CaF at 606.440 nm by HR-CS-ETAAS. The optimised graphite furnace
program is given in Table 1. To cover the graphite tube and
platform with zirconium, 20 lL of 1 mg mL1 Zr as the nitrate
was pipetted, dried and then thermally treated at 1100 C for
10 s (Gleisner et al., 2010). The procedure was repeated 10 times.
For Ir, the same procedure was applied. Standard addition technique
was preferred in all quantifications. Certified reference standard
was diluted 10 times before analysis whereas milk samples
were directly used without any dilution