Spectrophotometric Determination of Cationic Surfactants Using Patent Blue V: Application to the Wastewater Industry in Algiers

Abstract

Patent Blue V has been applied in a solvent extraction spectrophotometric method for the determination of cationic surfactants (CS) in industrial wastewaters. The method is based on the introduction of Patent Blue V as an anionic dye, and the formation of an ion pair association with CS in chloroform under the studied extraction conditions. The maximum wavelength of absorption for the ion pair is located at 627 nm, and a molar absorption coefficient of higher than 3.6 9 10 5 l mol -1 cm -1 was obtained. The calibration curve was linear between 0 and 5.48 9 10 -6 M, and exhibited a significant coefficient of correlation. Based on the calculated values for the relative standard deviation (%) over the studied concentration range, the method was found to be highly sensitive, and the deduced limit of detection for the method was found to be very low (8.6 9 10 -8 M of CTAB). It was also found that a washing step was necessary for the organic extract in order to remove interferences caused by foreign ions and species present in unknown samples. To validate this method, the procedure was used to determine the CS contents of samples collected from textile industry wastewaters in the Algiers region. The results obtained showed good agreement for the proposed method.

In-syringe magnetic stirring assisted dispersive liquid–liquid micro-extraction with solvent washing for fully automated determination of cationic surfactants

“…The final solvent volume (175 µL) was calculated from the flow rate during the measurement step, peak width (7 s), the sensitivity 25 (slope), the used volume of sample, and the molar extinction coefficient of DSB of about 47,000 AU L mol -1 . 39 In comparison with prior indicated applications using FT for the determination of CS, the excellent sensitivity and low detection limit of 12 nmol L -1 (4.4 ppb) should be pointed out, which were 30 found be superior to the former works. On the other hand, one analysis required a significantly longer time due to batch-wise operation and employing both analyte extraction and extract washing.…”

Monitoring of Anionic Surfactants in a Wastewater Treatment Plant of Algiers Western Region by a Simplified Spectrophotometric Method

“…In order to choose an AS suitable for this method, DS, extensively commercialized in Algeria because of its low cost, and dodecylbenzene sulfonate (DBS), frequently used in the spectrophotometric method [28], were tested. Absorption spectra for aqueous solutions of CV and the ion pair extracted with DS and DBS are shown in Fig.…”

“…Methods used for qualitative and quantitative analysis of surfactants include titration [20], flow injection analysis (FIA) [21], voltamperometry [22], chromatography [23], capillary electrophoresis [24], potentiometry [25], and optical sensors [26]. Spectrophotometric determination of surfactants is an economic and simple commonly used method [27][28][29][30].…”

Analysis of Surfactants in Environmental Samples by Chromatographic Techniques

“…However, the tendency of surfactants to concentrate at phase boundaries leads to the formation of emulsions, and phase separation during LLE becomes very difficult. This can be avoided by the formation of liphopilic ion pairs between surfactants and ion-pair reagents [1] (e.g., disulphine blue dyes or LAS for cationic surfactants [65,77,82], methylene blue [78,79,83] or methylene green for anionic surfactants [84], modified Dragendorff reagent for non-ionic [81]). …”