Cethyltrimethylammonium bromide ctab

All chemicals used are of at least analytical reagent grade. Cobalt chloride hexahydrate (CoCl₂·6H₂O), metal ions studied for interferences, pyrocatechol violet and nitric acid were obtained from Carlo-Erba, France. 1-Undecanol, 1-dodecanol, dodecyltrimethyl ammonium bromide (DTAB), trimethyltetradecyl ammonium bromide (TTAB), and cethyltrimethyl ammonium bromide (CTAB) were purchased from Sigma-Aldrich (USA). 1-Octanol was obtained from Panreac (Spain). Methanol (HPLC grade) and acetonitrile (HPLC grade) were obtained from Merck (Germany). Acetone was purchased from Q-rac (Malaysia). Sodium sulphate anhydrous was purchased from Fluka (Japan). Sodium chloride, sodium hydrogen phosphate and sodium dihydrogen phosphate were purchased from Ajax Finechem (Australia). Aluminium chloride was obtained from Ajax Finechem Pty Ltd (New Zealand). All solutions were prepared using deionized water with the resistivity of 18.2 MΩ cm from RiOs™ Type I Simplicity 185 (Millipore Waters, USA). Stock solution of standard Co(ii) 100 mg L⁻¹ (or 1.695 mmol L⁻¹) was prepared and used throughout.

Dulbecco’s Modified Eagle Medium and fetal bovine serum (FBS) were purchased from Gibco (Thermo Fisher Scientific, Waltham, MA, USA). Cobalt Hexahydrate, hydrogen tetrachloroaurate (III) trihydrate (HAuCl₄·3H₂O) and ethylene chloride were purchased from Alfa Aesar (Heverhill, MA, USA). Cethyltrimethylammonium bromide (CTAB) and 1-Butanol were purchased from Sigma-Aldrich (St. Louis, MO, USA). Isooctane was purchased from Tedia (Fairfield, OH, USA). Methotrexate (MTX), sodium borohydride were purchased from Acros organics (Fair Lawn, NJ, USA), silver nitrate (AgNO₃), ascorbic acid and citric acid were purchased from Honeywell Riedel-de Haen (Seelze, Germany). 2-Aminoethanethiol was purchased from Tokyo Chemical Industry (TCI, Tokyo, Japan). All other chemicals of analytical grade were purchased from Sigma (St. Louis, MO, USA).