Micellar-Sensitized Spectrophotometric Determination of Magnesium in Drinking Water

摘要: A sensitive and relatively selective spectrophotometric method is proposed for the rapid determination of magnesium using Eriochrome black T (EBT) as a complexing agent in presence N-cetyl-N,N,N-trimethylammonium bromide (CTAB). The complex formation reaction between EBT (II) instantaneous NH 3 /NH 4 Cl buffer at pH 9.5 after CTAB adds micellar-sensitized medium absorbance analytical signal remains stable over 6 h. N-cetyl N,N,N-trimethylammonium cationic surfactant Triton X-100 nonionic are used improving sensitivity solubility system, respectively. surfactant-sensitizing allows concentration range 0.05-1.2 µg mL –1 with molar absorption coefficient 8928 L mol cm Sandell’s 2.82 ng 2- . has detection limit 0.012 (DL=3S b /m) quantification 0.054 (QL=10S an measurement wavelength 640 nm bathochromic shift 86 nm. selectivity chelating reagent was improved by use 1 masking solution containing 0.1 M EDTA, 0.01 triethanolamine 5000 µgNaF been successfully applied to trace levels different drinking water samples. precision (with CV 2.35%) accuracy obtained were highly satisfactory.