ULTRASOUND-ASSISTED EMULSIFICATION MICROEXTRACTION OF VARIOUS PRESERVATIVES FROM COSMETICS, BEVERAGES, AND WATER SAMPLES

Abstract

In the present work, an efficient method based on ultrasound-assisted emulsification microextraction was developed for the determination of sodium benzoate (SB), p-hydroxybenzoic acid (PHBA), methyl-paraben (MP), ethyl-paraben (EP), and propyl-paraben (PP) in different samples. In this procedure, 40 μL of (5% w/v) aliquot 336 in 1-octanol was injected slowly into a 12-mL home-designed centrifuge glass vial containing an aqueous sample of the analytes that was located inside the ultrasonic water bath. The formed emulsion was centrifuged and the separated organic solvent was then injected into a 20-μL loop of high performance liquid chromatography coupled with UV detector. Under the optimum conditions, preconcentration factors (PFs) in the range of 109–490 were obtained. The performance of the proposed method was studied in terms of its linear range (LR, 0.6 μg/L up to 10000 μg/L), linearity (R² ≥ 0.9963), precision [RSD% ≤ 3.6; reproducibility, RSD (%) ≤ 9.8] and extraction recoveries (22.6–102.1%). Limits of detections (LODs) were 8.3, 1.2, 0.60, 0.42, and 0.25 μg/L for SB, PHBA, MP, EP, and PP, respectively. Finally, the applicability of the proposed method was evaluated by the extraction and determination of the target analytes from beverages, cosmetics, and water samples.

Keywords:

• beverages
• comestics
• p-hydroxybenzoic acid
• parabens
• sodium benzoate
• ultrasound-assisted emulsification microextraction

Notes

^a Preconcentration factors were calculated based on extraction of 4.2 µg/L of each paraben, 8.3 µg/L of p-hydroxybenzoic acid, and 83 µg/L of sodium benzoate.

^a Preconcentration factor.

^b Corona-charged aerosol detector.

^c Large-volume sample stacking non-aqueous capillary electrophoresis with diode array detector.

^d Membrane-assisted liquid-liquid extraction.

^a Initial concentiation, Concentration of analytes (µg/L) in the sample after preparation.

^b Found, Concentration of analytes (µg/L) in the sample after spiking of target analytes.

^c Added, Spiked concentration (µg/L).

^d PHBA, p-hydroxybenzoic acid; SB, sodium benzoate; MP, methyl-paraben; EP, ethyl-paraben; PP, propyl-paraben.