Study On The Determination Of Alkaline-earth Elements In The Titanates With FAAS

The titanates are fine chemical products with high-value-added and broad prospects, which posses advantages of wide raw material sources,simple synthesis method, low cost and easily doping. With the development of the electronics industry, particularly the production requirements of sensitive components and the establishment of quality management system, it needs higher quality control of electronic components' raw materials. The impurity content index of the titanates raw material develops increasingly in the direction of trace amount even ultra trace amount. Therefore, the establishment of a simple and reliable analysis method has become the focus of research.In flame atomic absorption spectrometry (FAAS), the sensitivity of alkaline-earth elements except magnesium is not high. In determinating the impurity content of super purity powders, massive substrate disturbance will reduce sensitivity even more. In order to solve the problem, sensitization and sensitization mechanism of organic reagents were researched in detail in this paper. First, the best instrument conditions were identified by orthogonal test in the presence of organic reagents. Then, under the best conditions, the sensitization of organic reagents to the alkaline-earth elementss was studied. The results showed that the formic acid has the best sensitization to strontium, barium and calcium and the sensitization value were up to 70 %, 54% and 55% respectively.The sensitization mechanism of formic acid to alkaline-earth elements was deeply studied too. The results showed that formate was produced by alkaline-earth elementss and formic acid in the process. At a lower temperature, formate quickly was broken down into carbonate, and then carbonate was broken down into oxide. At the same time, due to the quick decomposition reaction and the strong surfactivity of oxide, oxide was easily reduced to atoms in reducing atmosphere of formic acid or acetic acid. Thus the conventional mechanism of flame atomization was changed and the efficiency of flame atomization was improved.Influences of deionization reagent, releasing reagent and protecting reagent on eliminating or reducing the substrate disturbance were studied. Finally indicated, La3+ has the best obvious effect on eliminating substrate disturbance.The sensitization of formic acid and the shelter of La3+ were used in the determination of strontium in barium titanate samples. Linear range was from 0 to 1.6×10-2 g/L, the detection limit was 0.014 mg/L and the recovery rate was from 100% to 109%.