Dear All, I work towards realizing Aerospace parts. We etch Aluminum by phosphoric acid. Procedure requires us to do atomic absorption for finding the quantity of dissolved aluminum in acid solution. I do not have facility for Atomic absorption method though I have an acceptable facility for normal titration (volumetric analysis) compatible to Aerospace requirements. Can you suggest any method of finding dissolved aluminum in acid solution? Regards Nikhilesh Lal Hyderabad, India.