Cloud Point Extraction of Polycyclic Aromatic Hydrocarbons in Aqueous Solution with Nonionic Surfactants

Abstract

A cloud point extraction (CPE) process using the two nonionic surfactants, Tergitol 15-S-9 and Tergitol 15-S-7, mixtures of secondary ethoxylated alcohols, to extract selected polycyclic aromatic hydrocarbons (PAHs) from aqueous solutions at 25°C was investigated. Cloud point temperatures (CPTs) of selected nonionic surfactants were studied against the effect of added electrolytes on their cloud points. Sodium iodide could increase the cloud points of selected nonionic surfactants, i.e., the salt-in effect, whereas sodium chloride, sodium phosphate and sodium sulfate could decrease the cloud point, i.e., the salt-out effect. Cloud point temperatures (CPTs) of these micellar solutions were regulated and reduced enough with addition of sodium phosphate and sodium sulfate, so that the cloud point extraction (CPE) process could be facilitated at 25°C. It was found that a higher preconcentration factor could be achieved in the micellar solution having a lower surfactant concentration. The average preconcentration factor was also discussed as a function of surfactant concentration used in the CPE process.

Determination of carcinogenic herbicides in milk samples using green non-ionic silicone surfactant of cloud point extraction and spectrophotometry

“…Up to now, non-ionic surfactants (mainly polyoxyethylenenated alkyl phenols, from PONPE 7.5 and Triton series such as Triton X-100 and Triton X-114) are the most widely employed for organic compounds analysis with CPE. [ 9 , 10 ]. Triton X-114 is well known for micelle formation compared to other classes of non-ionic surfactant.…”

Phenylethyl Isothiocyanate Extracted from Watercress By-Products with Aqueous Micellar Systems: Development and Optimisation

“…As indicated by Katsoyannos et al [18], micellar systems using non-toxic surfactants (non-ionic, without branched aliphatic chains or aromatic moieties) are suitable for the isolation of natural antioxidants, which can then be used in dietary applications. Among non-ionic surfactants, polyethoxylates are the most numerous and technically interesting [15], standing out for their widespread use Triton (X-100 and X-114), Brij (−30, −56 and −97), Genapol (X-080), and to a lesser extent, the Tergitols (15-S-X), among others [19][20][21][22][23]. Genapol X-080 is a structured non-ionic surfactant of the ethoxylated primary aliphatic alcohols type, with a hydrophobic chain of 12 alkyls and 8 oxyethylene groups (OEs) in its hydrophilic region.…”

Assessment of Methodological Pipelines for the Determination of Isothiocyanates Derived from Natural Sources

“…A major advantage of using micelles is that their transparency in the 240-280 nm region allows the monitoring of aromatic or conjugated systems more easily. In addition, nonionic surfactants have the capacity for developing interactions with wither hydrophobic or hydrophilic parts of the different molecules, allowing their extraction and purification more effectively [98,[275][276][277][278]. Specifically, upon extraction of PEITC (from watercress) with either alcohol ethoxylate non-ionic surfactants (e.g., Genapol X-080 and Tergitol 15-S-7) or a range of organic solvents of decreasing polarity (e.g., n-hexanes and a mixture of acetonitrile/chloroform; 10:7), results suggested that its extraction with non-ionic surfactants was the most efficient one.…”