Gallium, spectrophotometric

The sensitive and selective spectrophotometric methods involve extraction of ion-associates of the GaCU" ion with basic dyes (e.g., Rhodamine B). Methods based on ternary complexes of gallium with chelating triphenylmethane reagents (e.g., Eriochrome Cyanine R) and some surfactants are very sensitive but less selective. 

A comparison has been made of spectrophotometric methods based on extraction of the ion-associates formed by GaCU and basic triphenylmethane or diphenylnaphthylmethane dyes. The best reagent of this class for determining gallium appears to be Crystal Violet (e = 4.9-10 at 589 nm in CHCI3 acetone = 6 1) [28]. Brilliant Green [28] and Victoria Blue 4R [28,29] can also be used. 

Gallium ions form coloured complexes with a number of triphenylmethane chelating reagents besides Eriochrome Cyanine R. Pyrocatechol Violet (PV) gives with Ga and diphenylguanidine a ternary complex, extractable into n-butanol-CHCh (1-fl) mixture (e=1.08-10 ) [32]. In another extractive spectrophotometric method with PV,... 

The following spectrophotometric reagents were applied for determining indium 2-(2-thiazolylazo)-p-cresol (TAC), in catalysts [47] Malachite Green, in gallium metal and in ZnGeAs2 [53] and Pyrogallol Red, in zinc alloys [7]. 

Extraction and spec A = 510 nm of gallium with 4-(2-pyridylazo)resorcinol Comparison of the determination of gallium by a rhodamine B spectrophotometric method and by an AA method based on preliminary solvent... 

Nazarenko, V.A, Antonovich, V.P., and Nevskaya, E.M. (1968) Spectrophotometric determination of the hydrolysis constants of gallium ions. Russ. J. Inorg. Chem., 13, 825-828 (English translation). 

---