Abstract
Effects of various sheath gases for the measurement of aluminum, calcium and copper in flameless atomic absorption have been studied. The sheath gases used for this work were helium, nitrogen, argon and sheath gases mixed hydrogen in pure sheath gases. The atomic absorption spectrophotometer was used a Hitachi Model 308, equipped with a Perkin-Elmer HGA-2100 graphite tube furnace. The results of this experiment were suggested as follows. (1) The common logarithm of atomic absorbance can be expressed by linear function for flow rates of the sheath gases. The linear function is divied into a type helium and a type argon. The nitrogen sheath gas belongs to one of the type argon. (2) A plot of logarithm of atomic absorbance vs. argon flow rates expresses the type helium at argon gas flow rate more than a constant. (3) A difference between the type helium and the type argon is recognized by the diffusion coefficient of sheath gases. (4) In H2-Ar sheath gas, the atomic absorbance [A] of aluminum has been obtained as a function of hydrogen concentration [H]. [A] =K/[H]0.52 K……constant (5) The atomic absorbance of aluminum and calcium decreases under the nitrogen sheath gas in comparison with the argon gas, or the atomic absorbance of aluminum and copper decreases under the sheath gases of hydrogen and other gas in comparison with the argon gas.
