N-ACETYL-N-PHENYLHYDROXYLAMINE AS A SPECTROPHOTOMETRIC REAGENT FOR IRON

N-Acetyl-IV-phenylhydroxylsmine furnishes purple, orange, and yellow coloured, water-soluble complexes with Fe(III) at pH below 1.2. between 1.8 and 3.5, and chose 4.0 with absorbance peaks at 490, 470, and 425 m\(\mu\). respectively. Pruple-coloured complex is unstable. Orange complex is considered most suitable For detailed study as in its pH range there is less interference from foreign ions. The system obeys Beer's law in the concentration range of 1 to 12 p.p.m. of iron at 470 m\(\mu\). Most of the commonly associated ions do not interfere. The reaction is not masked by tartrate, phosphate, and cyanide. The sensitivity of the colour reaction, determined in Nessier's cylinder, is 1 part of iron in 4.500,000 parts of solution and on spot plate is 0.2\(\gamma\) of iron. The molecular extinction coefficient at 470 m\(\mu\), and at pH 2.8 is 3.07 X 103