Abstract
A simple potentiometric protocol for the assay of the sulfated polysaccharide dextran sulfate (DS) is discussed, based on single-use plasticized poly(vinyl chloride) (PVC) /polyurthane (PU) polyion membrane probes incorporating a quaternary ammonium transducer (tridodecylmethylammonium chloride, TDMAC). A disposable polycationic protamine sulfate (PS) probe, based on dinonylnaphthalene sulfonate (DNNS), is also introduced and used as a tool for end point detection. The DS sensor probes exhibited a detection limit of 0.759 ppm in a 120 mM NaCl background saline solution, a linear range of 0.955 - 4.467 ppm DS, with a slope of -28.1 mV/decade concentration, and an overall potential change of 103.7 mV. The fabricated probes were successfully applied in the determination of DS levels of several energy drink samples, a pharmaceutical formulation, and an industrial polyelectolyte sample.