Volatilisation of zirconium, vanadium, uranium and chromium using electrothermal carbon cup sample vaporisation into an inductively coupled plasma

Zirconium, vanadium, uranium and chromium react with ammonium chloride (7%m/V) when heated in an electrothermal carbon cup to form their corresponding chlorides. These metal chlorides are subsequently vaporised into an inductively coupled plasma for optical emission spectroscopy. The preferential halide formation of these refractory elements in the electrothermal carbon cup has allowed their determinations to proceed with sub-nanogram detection limits and adequate precision of about 6% relative standard deviation for 5-µl samples. Linear dynamic ranges span about three orders of magnitude.