engleski

Potentiometric determination of cationic surfactants using chemically functionalized carbon nanotubes based electrode

Cationic surfactants (CSs) are widely used in bactericidical, algaecidical, fungicidical, disinfection and anticorrosive products, as cosmetic and pharmaceutical components, etc. The reference method for their determination is two-phase titration [1]. The method have many disadvantages, the largest of which is the use of toxic organic solvents. Considering that, it is of great importance to find alternative method for CSs determination. CSs selective electrodes proved to be a good sensors for CS determination [2]. Their membrane usually consists of sensor material, plasticizer and PVC [3]. Nanomaterials, as component of the membrane can significantly improve sensor properties[4]. Using solid-contact electrodes without an inner e lectrolyte, additionally improve sensors, solving problems as leaching of the sensor material, signal stability and sensor life-time [5]. The sensor material of the electrode was prepared by chemically functionalization of multiwalled carbon nanotubes (MWCNT) with –OSO3-CP+ group. Developed sensor was used as detector in potentiometric titrations of CSs. Hyamine, cetylpyridinium chloride (CPC), hexadecyltrimethylammonium bromide (CTAB) and 1, 3-didecyl-2-methylimidazolium chloride (DMIC) were used as the analytes during the potentiometric titrations, and sodium dodecyl sulfate (NaDDS) was used as the titrant. The applicability of the sensor was tested in three commercial products with different concentrations of CSs. The results of CSs determination in commercial products were compared with those obtained by the reference method and showed the excellent correlation between the methods.

cationic surfactants ; chemically functionalized carbon nanotubes ; potentiometric titrations

nije evidentirano