Modifier effect of aluminum sulfate on the zinc determination by electrothermal atomic absorption spectrometry

Tn the present work, the modifier action of aluminum sulfate on zinc has be en investigated. Nickel chloride was chosen as an interferent because it wa s found to have a highly suppressive effect on zinc. In the presence of nic kel chloride, zinc losses begin even at a pyrolysis temperature of 200 degr ees C, and signals are completely suppressed due to volatilization of zinc chloride above 600 degrees C. Upon addition of aluminum sulfate a pyrolysis temperature of at Least 1200 degrees C can be applied without losing the a nalyte element. This is higher than that in the presence of Pd-Mg modifier. An amount of 4 mu g Al-2(SO4)(3) is found to be effective to prevent the l osses due to nickel chloride. The interaction mechanism of aluminum sulfate with zinc was investigated and compared with that of magnesium nitrate for their stabilizing power on zinc.