Synthesis and analytical applications of 2,4-dinitro-6-chlorophenylazothymol.
The newly synthesized 2,4-dinitro-6-chlorophenylazothymol, a weak acid with pK(a) 8.33 +/- 0.04 at 27 degrees, is proposed as a sensitive spot reagent for magnesium, with an identification limit of 0.14 microg at pH 10.5-11.6. Silver and manganese(II) interfere but can be masked by means of cyanide and periodate respectively. There is little interference by anions. The reagent also serves as an acid-base indicator with a transition interval of pH 7-9, giving a sharp colour change at the equivalence point.
Mukerji
S K
SK
Geological Survey of India, Rajasthan Circle, Jaipur, India.
Sharma
H L
HL