Flame Photometric Analysis with Wavelength Shift Using AA-7000

Introduction

The AA-7000 atomic absorption spectrophotometer can also be used as a flame photometer. In this application, the hollow cathode lamp required for atomic absorption analysis is unnecessary because atomic emission (flame emission) is measured. Excellent sensitivity can be obtained in measurement of such alkaline elements and alkaline-earth elements as Na, K, Ca and Sr as target elements because their analysis wavelengths are in the long wavelength region where there is little influence from flame emission. However, when measuring samples which contain many coexisting substances along with these elements, background emission due to these coexisting substances might be generated, requiring correction for these influences. The AA-7000 is equipped with a wavelength shift function which allows setting of 2 analysis wavelengths. Thus, background correction can also be conducted using flame photometric analysis by first conducting measurement at the normal analysis wavelength of the total atomic emission and background emission, and then shifting the analysis wavelength by a few nm to conduct measurement of only the background emission. Here we introduce the measurement of potassium in sodium chloride, using the wavelength shift function to correct for the background influence.

October 28, 2009 GMT