X-Ray Photoacoustic Spectrometry Applied to Determination of Iron in Aluminum Hydroxide Gel

Abstract

An attempt was made to determine the iron in an aluminum hydroxide gel powder by an X-ray photoacoustic measurement. It was conducted using a monochromated X-ray beam (1.504 A) of synchrotron radiation as an excitation source. The iron in the sample was also determined by a spectrophotometric method, while the water content in the sample was determined from the weight loss by a thermal analytical method. Photoacoustic signal intensities roughly agreed with those calculated from the elemental compositions of the samples. The rough agreement is due to the fact the background signal from the aluminum hydroxide gel was not negligibly small. However, the background signal decreased in measurements at high chopping frequency, and the calibration curves of iron showed good linearities. The photoacoustic signal intensity of samples containing iron varied as f −1 , where f is the chopping frequency. This was different from that for a sample without iron