Determination of nonionic surfactants by spectrophotometry after extraction with potassium triiodide

✍ Scribed by Anna A. Boyd-Boland; James M. Eckert

• Publisher: Elsevier Science
• Year: 1993
• Tongue: English
• Weight: 314 KB
• Volume: 271
• Category: Article
• ISSN: 0003-2670
• DOI: 10.1016/0003-2670(93)80060-x

✦ Synopsis

A method 1s described for the determmatlon of nomomc surfactants m the concentration range 0 l-l mg 1-l The surfactant IS extracted into l,l,l-tnchloroethane as an uncharged adduct vvlth potassium truodlde and the determmatlon IS completed by measuring the absorbance of the extract at 380 nm The performance of the method m the presence of amomc surfactants and the major Ions of sea water is assessed Keywords Spectrophotometry, Extraction, Sea water, Surfactants, Waters

Reagents contammg Iodine and potassium lodude m water have been used previously m spectrophotometrlc studies of nomomc surfactants Baleux [l], for example, determmed ethoxylate m the concentration range l-20 mg I-' ante measurements at 500 nm after addition of an lodme-iodide reagent Others have studied the interaction of lodme-iodide and nonlomc surfactants as a function of the oxyethylene cham lengths of the surfactants [2,3] This paper describes a method for the determination of nomomc surfactants involving extraction of a neutral adduct of surfactant, lodme and potassmm iodide and spectrophotometry of the extract The new method differs m three ways from previous applications of an lodme-iodide reagent mcluslon of a hquld-liquid extraction step, the choice of wavelength (380 nrnj and the