Different nonionic surfactants such as Tween 20, Ponpe 7.5, Triton X-114, Triton X-45 and Triton X-100 were tested in the CPE procedure.
This surfactants are widely employed in inorganic (trace metals) and organic trace analysis (environmental contaminants like phenols, pesticides and herbicides) by CPE due to their commercial availability, low toxicity, high density, and low cloud
point temperature.
The dependence of CPE to nonionic surfactants concentration was examined in the range of (0.0–0.8)% (v/v) in the presence of Sn(IV) for each surfactant.
The results are shown in Fig. 4.
The best analytical signal was obtained in presence of Tween 20.
Tween 20 is a nonionic surfactant that consists primarily of fatty acid esters of polyethoxy sorbitan.
It finds widespread use as emulsifiers, defoamers, dispersants, and stabilizers in food, cosmetics, and biodegradation media (Adamantini & Vassilis, 1995).
Its physiochemical properties are given in Scheme 2.