Synthesis of 5-(5-nitro-2-pyridylazo)-2,4-diaminotoluene and its application to spectrophotometric determination of microamounts of palladium.
A new pyridylazo reagent, 5-(5-nitro-2-pyridylazo)-2,4-diaminotoluene (5-NO(2)-PADAT) has been synthesized, and found to be a good chromogenic reagent for palladium. In sulfuric acid, hydrochloric acid and perchloric acid palladium reacts with 5-NO(2)-PADAT to form a 1:1 chelate, exhibiting an absorption maximum at 592 nm. The apparent molar absorptivity is 1.25 x 10(5) l(-1) mol(-1) cm(-1). Beer's law was obeyed in the range 0-0.9 microg ml(-1) Pd. Relatively large amounts of co-existing elements, including all other noble metals, can be tolerated. The method is simple and rapid, with high sensitivity and good selectivity and was applied to the determination of palladium in some industrial samples with satisfactory results.
Yang
H
H
Experimental Centre, Shaanxi Normal University, Xi'an, People's Republic of China.
Zhang
G
G
Zhang
L
L
Liu
G
G
Zhang
X
X