This International Standard specifies three methods for the determination of cobalt, nickel, copper, zinc, cadmium and lead in water by flame atomic absorption spectrometry: Section1 : method A, for direct determination by flame atomic absorption spectrometry; Section2 : method B, for determination by flame atomic absorption spectrometry after chelation (APDC) and extraction (MIBK); Section3 : method C, for determination by flame atomic absorption spectrometry after chelation (+MA-+MDC) and extraction (DIPK-xylene).