Masking agents in the spectrophotometric determination of metal ions with 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol and non-ionic surfactant

Abstract

Efficient masking methods were found for the selective spectrophotometric determination of metal ions with 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol in a micellar solution of a non-ionic surfactant. N-(Dithiocarboxy)sarcosine (DTCS) and nitrilotriacetic acid were good choices for the determination of iron(II). Triethylenetetraamine and DTCS (or dimercaptosuccinic acid and diethylenetriamine) were an excellent combination for the specific determination of manganese(II). A combination of pyrophosphate and ethylene glycol bis(2-aminoethyl ether)-N,N,N′,N′-tetraacetic acid was useful for the determination of cobalt(II). Hence, iron, manganese and cobalt were determined with high selectivity in various samples such as natural waters, metal samples and soil.