A New Sensor for Determination of Anionic Surfactants in Detergent Products with Carbon Nanotubes as Solid Contact. Issue 4 (25th May 2017)

• Record Type: Journal Article
• Authors: Sakač, Nikola; Jozanović, Marija; Karnaš, Maja; Sak‐Bosnar, Milan
• Is Part Of: Journal of surfactants and detergents. Volume 20:Issue 4(2017)
• Page Start: 881
• Page End: 889
• Publication Date: 2017-05-25
• Subjects: Surfactant sensor -- MWCNT -- Anionic surfactant -- Potentiometric titration -- Detergents; Surface active agents -- Periodicals; Detergents -- Periodicals; 668.1
• DOI: 10.1007/s11743-017-1978-0
• Languages: English
• ISSNs: 1097-3958

Abstract

Abstract: A new solid‐state sensor for potentiometric determination of surfactants with a layer of multi‐walled carbon nanotubes was prepared. As a sensing material, 1, 3‐didecyl‐2‐methylimidazolium–tetraphenylborate ion‐pair was used. The investigated sensor showed a Nernstian response for both dodecylbenzenesulphonate (DBS, 57.6 mV/decade of activity between 5 × 10 −7 to 1 × 10 −3 M) and sodium lauryl sulfate (LS, 58.4 mV/decade of activity between 2 × 10 −7 to 2 × 10 −3 M). It responded in 8–10 s for each ten‐fold concentration change in the range of 1 × 10 −6 to 3 × 10 −3 M. The detection limits for DS and DBS were 2 × 10 −7 and 3 × 10 −7 M, respectively. The sensor revealed a stable response (signal drift 2.6 mV/h) and exhibited satisfactory selectivity performances for LS over most of the anions generally used in surfactant‐based commercial detergents. The main application of this sensor was the end‐point determination in potentiometric titrations of anionic surfactants. The (diisobutyl phenoxy ethoxy ethyl)dimethyl benzyl ammonium chloride (Hyamine), cetyltrimethylammonium bromide, hexadecylpyridinium chloride monohydrate (HDPC) and 1, 3‐didecyl‐2‐methylimidazolium chloride were tested as potential cationic titrants, and all exhibited analytically usable titration curves with well‐defined equivalence points. The standard solution of HDPC was used as a cationic titrant by all potentiometric titrations. The operational life‐time of the sensor described was prolonged to more than 3 months.