Flame Method Measurement of Na and K in Soy Sauce Using the Burner Angle Adjustment Function

Introduction

While the flame atomic absorption method is a rapid and stable measurement technique, due to the narrow linear range of absorbance, in most cases the dilution factor of the measurement sample must be changed according to the element sensitivity so that absorbance falls within the linear range (usually 0.3 to 0.5 Abs or less). However, as the dilution factor increases, dilution errors and contamination from containers and reagent additives can also become an issue. Although changing the measurement wavelength is one method for adjusting absorbance, there are many instances where there is no other wavelength that allows acquisition of appropriate absorbance. On the other hand, adjusting absorbance by adjusting the burner angle allows for continuous adjustment down to about 1/20 and this method can be used with basically any wavelength. This article introduces an example of measuring Na and K in soy sauce by changing the burner angle.

April 27, 2017 GMT