Study On Analysis Capability Of Oxygen Doped Air-Acetylene Flame Atomic Absorption Spectrometry

Flame Atomic Absorption Spectrometry (FAAS)is a simple and efficient testingtechnology with good detect limit and precision for daily analysis task. Theconventional air-acetylene FAAS is hard to determine the elements with high meltingpoint and boiling point. The oxygen doped air-acetylene flame is a new type of hightemperature flame. It is developed from the basis of air-acetylene flame. Becauseoxygen is doped and the amount of burning acetylene increased, the temperature offlame is raised. Simultaneously, adjusting the flow proportion of oxygen to acetylenecan enhance the reducing atmosphere of flame. That is all benefit for atomization ofoxide. But the reports for principium research and practical application ofO2-air-C2H2 FAAS is scarce recently, enough data of element determined number andtheir levers of analysis capability are absent, Relative document of excludingdisturbance are infrequent too. Potential users are not familiar with O2-air-C2H2FAAS. I selected the study on analysis capability of O2-air-C2H2 FAAS as my masterdissertation in order to provide principium data and better guide for popularity of it. This paper described two lines absorption way of Gallium to determine thetemperature of O2-air-C2H2 flame and investigated systematically 30 elements withlow, middle, high melting point and boiling point from these aspect:Optimumconditions, the interference effect of coexisting elements, enhancing effect,characteristic concentration, detect limit, linear range. Many conclusions weredrawn. 1. O2-air-C2H2 flame temperature can be adjusted between 2300-2900K by control the flow rate of O2 and C2H2. Doped oxygen can react with surplus acetylene in fuel enriched flame and release heat. So the flame temperature is raised. After the flow rate of oxygen and acetylene are chosen, the relative high temperature can be obtained between 2300 and 2900K. The temperature is 300-500K higher than conventional air-acetylene flame. That is the key reason which O2-air-C2H2 FAAS excel air-C2H2 FAAS for determining the elements of middle temperature of melting and boiling. 2. O2-air-C2H2 flame is a better reducing atmosphere flame than air-C2H2 flame. The amount of free group C*,C2*,CH*,CO*are added by controlling the flow proportion of oxygen and acetylene 3. O2-air-C2H2 FAAS is not suitable for determining the elements whose melting point and boiling point are about 2000K and separation energies of their oxide are not more than 5.0eV. Using apparatus of oxygen doped, the absorptionlight length is contracted and perhaps there are ionization and dilute effect, the analytical performance get worse4. Those elements whose temperature of melting and boiling lie in 2300— 2800K and separation energies of their oxide lie in 4.5— 6.0eV can be better determined with O2-air-C2H2 FAAS than conventional air-C2H2 FAAS. Because flame temperature and reduction atmosphere are raised.5. Those elements whose melting point and boiling point exceed 2800K and separation energies of their oxide surpass 7.0eV can also be determined with O2-air-C2H2 FAAS. but the temperature addition is limited. The determination sensitivities are not still ideal. It is hardly applied to determining real samplesMoreover, many new methods for determination of trace vanadium,titanium,beryllium in geological samples and trace silicon in steel samples are developedin this paper. Lastly, the development prospect of O2-air-C2H2 atomic absorptionspectrometry is anticipated.