engleski

A New Sensing Material for the Potentiometric Determination of Anionic Surfactants in Commercial Products

A new potentiometric sensor for the determination of anionic surfactants (ASs) was constructed based on the dimethyldioctadecylammonium-tetraphenylborate (DDA-TPB) ion pair as a sensing material. This sensitive, accurate, selective, rapid, simple and inexpensive sensor exhibited a Nernstian response for sodium dodecyl sulfate (NaDDS, 59.0 mV/decade) and sodium dodecylbenzene sulfonate (NaDBS, 59.1 mV/decade) over the range of 3 x 10^-7 to 8 x 10^-3 M for NaDDS and 4 x 10^-7 to 2 x 10^-3 M for NaDBS. The detection limits for both NaDDS and NaDBS were 2 x 10^-7 M. Different pH values, ionic strengths and commonly used nonionic surfactants, organic anions and inorganic anions did not have a significant influence on the sensor performances or the accuracy of ASs determination. The sensor was successfully applied to ASs determination in three commercial detergents with different percentages of ASs.

surfactant sensor; anionic surfactant; potentiometric titration; PVC membrane; commercial products

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