Gurkan, RamazanUlusoy, Halil IbrahimAkcay, Mehmet2024-10-262024-10-2620091306-3057https://doi.org/10.12973/ejac.2009.00057ahttps://hdl.handle.net/20.500.12418/28250A sensitive and relatively selective spectrophotometric method is proposed for the rapid determination of magnesium using Eriochrome black T (EBT) as a complexing agent in the presence of N-cetyl-N, N, N-trimethylammonium bromide (CTAB). The complex formation reaction between EBT and magnesium (II) is instantaneous in presence of NH3/NH4Cl buffer at pH 9.5 after CTAB adds as micellar-sensitized medium and the absorbance as analytical signal remains stable for over 6 h. N-cetyl N, N, N-trimethylammonium bromide as cationic surfactant and Triton X-100 as nonionic surfactant are used for improving the sensitivity and solubility of the analytical system, respectively. The surfactant-sensitizing method allows the determination of magnesium in the concentration range of 0.05-1.2 mu g mL(-1) with a molar absorption coefficient of 8928 L mol(-1) cm(-1) and Sandell's sensitivity of 2.82 ng cm(2-). The method has a detection limit of 0.012 mu g mL- 1 (DL=3S(b)/m) and quantification limit of 0.054 mu g mL-1 (QL=10S(b)/m) at an analytical measurement wavelength of 640 nm with a bathochromic shift of 86 nm. The selectivity of chelating reagent was improved by the use of 1 mL masking agent solution containing 0.1 mol L-1 EDTA, 0.01 mol L-1 triethanolamine and 5000 mu g NaF mL(-1). The proposed method has been successfully applied to the determination of magnesium at trace levels in different drinking water samples. The precision (with CV of 2.35%) and the accuracy obtained were highly satisfactory.en10.12973/ejac.2009.00057ainfo:eu-repo/semantics/closedAccessSurfactantsCTABEBTbathochromic shiftspectrophotometrymagnesium determinationArticle42140127WOS:000219980100001N/A