MERGING ZONES IN FLOW INJECTION ANALYSIS .3. SPECTROPHOTOMETRIC DETERMINATION OF ALUMINUM IN PLANT AND SOIL MATERIALS WITH SEQUENTIAL ADDITION OF PULSED REAGENTS

A flow injection procedure is described for the Spectrophotometric determination of aluminium in plant and soil material with eriochrome cyanine R. This system utilizes merging zones and sequential addition of pulsed reagents. A high degree of sample dispersion and pulsed neutralization reagent allow precise pH control; acid plant digests can therefore be analysed without pre-treatment. Iron(III) interference is avoided with ascorbic acid, and phosphate interference is negligible. The sampling rate is 120 samples per hour, reproducibility is better than 1% for a 5.0-ppm Al standard, and the calibration plot is linear in the range 0-20 ppm Al. Applied to soil and plant samples, the method gives recoveries of 98-101%. © 1979.