A simple solvent collection technique for a dispersive liquid–liquid microextraction of parabens from aqueous samples using low‐density organic solvent

Abstract

A simple technique for the collection of an extraction solvent lighter than water after dispersive liquid-liquid microextraction combined with high-performance liquid chromatography with ultraviolet detection was developed for the determination of four paraben preservatives in aqueous samples. After the extraction procedure, low-density organic solvent together with some little aqueous phase was separated by using a disposable glass Pasteur pipette. Next, the flow of the aqueous phase was stopped by successive dipping the capillary tip of the pipette into anhydrous Na(2)SO(4). The upper organic layer was then removed simply with a microsyringe and injected into the high-performance liquid chromatography system. Experimental parameters that affect the extraction efficiency were investigated and optimized. Under optimal extraction conditions, the extraction recoveries ranged from 25 to 86%. Good linearity with coefficients with the square of correlation coefficients ranging from 0.9984 to 0.9998 was observed in the concentration range of 0.001-0.5 μg/mL. The relative standard deviations ranged from 4.1 to 9.3% (n = 5) for all compounds. The limits of detection ranged from 0.021 to 0.046 ng/mL. The method was successfully applied for the determination of parabens in tap water and fruit juice samples and good recoveries (61-108%) were achieved for spiked samples.

Low Density Solvent‐Based Dispersive Liquid‐Liquid Microextraction for the Determination of Synthetic Antioxidants in Beverages by High‐Performance Liquid Chromatography

“…Organic solvent (1-octanol) was accumulated on the surface of aqueous phase as a small drop. After this process, a technique developed in our previous study was used for the simple and easy separation of a low density organic solvent [26]. Briefly, the organic solvent together with some little aqueous phase was pipetted by using a disposable glass Pasteur pipette.…”

Analytical Methodologies for the Determination of Personal Care Products in Water Samples

“…Nevertheless, due to the low volatility of these compounds, the usual analytical technique for their determination should be LC, preferably with MS/MS detection in order to increase the sensitivity and the selectivity. However, UV detection has been used in some cases [108,114,127]. Regarding LC-MS/MS, it is used by means of QqQ analyzers and in the ESI mode.…”

“…In this sense, classical DLLME has been employed for triclosan and triclocarban [113,114,119,125] and parabens [126,127,133]. In just one case, the parabens were previously derivatized, with anhydride acetic, to increase the extraction efficiency [126].…”

Pre-concentration of uranium from water samples by dispersive liquid–liquid micro-extraction

“…After extraction, phase separation is performed by centrifugation and the enriched target compounds in the organic phase are determined by spectrometry or chromatographic methods. The advantages of this technique are simplicity, rapidness, low cost, good efficiency and high enrichment factor [11][12][13].…”