Trace determination of zinc in standard alloys, environmental and pharmaceutical samples by fourth derivative spectrophotometry using 1-2-(thiazolylazo)-2-naphthol as reagent and ammonium tetraphenylborate supported on naphthalene as adsorbent.
A highly sensitive, selective, economical and rapid method for the trace determination of zinc using fourth derivative spectrophotometry has been proposed with 1-2-(thiazolylazo)-2-naphthol (TAN) as an analytical reagent and ammonium tetraphenylborate (ATPB)-naphthalene as an adsorbent. Zn-TAN is quantitatively retained on ATPB naphthalene in the pH range 6.5-9.5. The calibration plot is linear in the concentration range 0.02-1.4 mug ml(-1) Zn of DMF solution. The sensitivity of the method as determined from the slope of the calibration plot is 2.640 (d(4)A/dlambda(4))/(mug ml(-1)). Nine replicate determinations of 5.0 mug of zinc in 5 ml of DMF give a mean signal height of 2.660 (peak to peak height between lambda(1)=597 nm and lambda(2)=585 nm) with a relative standard deviation of 1.1%. The various conditions have been optimized and the developed method has been used for the determination of zinc in standard alloys, environmental and pharmaceutical samples.
Bhalotra
A
A
Chemistry Department, Indian Institute of Technology, Hauz Khas, New Delhi, 110 016, India.
Puri
B K
BK