1993 Volume 42 Issue 6 Pages 401-403
Simple, rapid and highly sensitive indirect determination of phosphate was studied by graphite furnace AAS using the absorbance of zinc. This method is based on the phenomenon that the decrease of atomization efficiency of zinc is proportional to the concentration of phosphate. In order to increase the effect of phosphate on zinc atomization efficiency, the atomization temperature was lowered from optimum atomization temperature (1300°C) to 1000°C. The detectable lower concentration of phosphate was 4 ppb with relative standard deviation of 3.0% using the optimum concentration of zinc (50 ppb). Silicate ion had 2.1 times effect and sulfuric acid had one fifth times effect of the phosphate at the concentration of 20 ppb. Nitric acid had less than one tenth effect of phosphate. The effect of the mixture of phosphate and other salts agreed well with the total effects of each one.
