This part of ISO 3815 specifies analytical methods for determining the chemical composition of zinc and zinc alloys in accordance with ISO 301 and ISO 752 by inductively coupled plasma optical emission spectrometry. This part of ISO 3815 includes provisions for preparation of test solutions and calibration solutions for zinc and zinc alloys. The ranges specified for each method can be extended and/or adapted for determinations of low concentrations. This part of ISO 3815 can be applied to other elements (e.g. Ni, Cr and Ti). However, such results will need to be carefully checked by taking into account the interferences, the sensitivity, the resolution and the linearity criteria for each instrument and each wavelength.