Abstract
When an acid solution is added to a mixed solution of IAA and formaldehyde, the solution fluoresces. The mixed solution in hydrochloric acid showed two excitation peaks at 330 nm and 380 nm, and only a single fluorescence peak at 490 nm. In this work, the optimum conditions, and interferences have been examined. From the result, the following analytical procedure is recommended : One ml of solution containing 1 × 10-55 × 10-7 mol/l of IAA and 1 ml of formalin (containing 37% formaldehyde) is added to 2 ml of 1N HCl. After standing for 45 min. at room temperature, the intensity of fluorescence at 490 nm (excited at 330 nm) is measured.
In this method, many kinds of diverse indole compounds interfered even in the same amount of IAA, while inorganic ions except Fe3+, Hg2+, and I- did not interfere.
The calibration curve was linear in the range of about 1 × 10-55 × 10-7 mol/l {(1.80.1) μg/ml} of IAA.
