Online dynamic pH junction–sweeping for the determination of benzoic and sorbic acids in food products by capillary electrophoresis

Abstract

A simple, low-cost, and efficient online focusing method that combines a dynamic pH junction and sweeping by capillary electrophoresis with polymer solutions was developed and optimized for the simultaneous determination of benzoic acid (BA) and sorbic acid (SA). A sample solution consisting of 2.5 mM phosphate at pH 3.0 and a buffer solution containing 15 mM tetraborate (pH 9.2), 40 mM sodium dodecyl sulfate, and 0.100 % (w/v) poly(ethylene oxide) were utilized to realize dynamic pH junction-sweeping for BA and SA. Under the optimized conditions, the entire analysis process was completed in 7 min, and a 900-fold sensitivity enhancement was achieved with limits of detection (S/N = 3) as low as 8.2 and 6.1 nM for BA and SA, respectively. The linear ranges were between 20 nM and 20 μM for BA and 20 nM and 10 μM for SA, with correlation coefficients greater than 0.992. The recoveries of the proposed method ranged from 90 to 113 %. These satisfactory results indicate that this method has the potential to be an effective analytical tool for the rapid screening of BA and SA in different food products.

Recent advances in the application of capillary electromigration methods for food analysis and Foodomics

“…In general, these additives can be obtained from nature or manufactured by the chemical industry. The main food additives analyzed by CE in the period covered by this review (2013–2015) were sweeteners , preservatives , and colorants .…”

“…Given the low concentration of preservatives in food samples different approaches have been employed to increase sensitivity. For instance, an online dynamic pH junction‐sweeping method was coupled to CE for the analysis of benzoic acid and sorbic acid . Dynamic pH junction together with sweeping demonstrated to significantly enhance sensitivity during CE analysis.…”

On‐line Concentration and Separation of Parabens by Micellar Electrokinetic Chromatography Using Polymer Solutions

“…Apparatus: All experiments were performed using a laboratory-made unit similar to a previously described system, 31 …”

“…[26][27][28][29][30][31] In order to reduce PEO adsorption on the capillary wall and thereby generate a high and repeatable EOF, the capillary is filled with 15 mM phosphate solution (pH 9.5) containing 20 mM SDS (Fig. 1A).…”

Simultaneous Determination of Benzoic Acid and Sorbic Acid in Food Products by Capillary Electrophoresis

“…Nevertheless, we observed the mixtures of benzoic and sorbic acid are used in some food products in Turkey. While several of the CE reports demonstrated the possibilities for simultaneous determination of benzoic and sorbic acids (Boyce, 1999;Frazier et al, 2000;Kuo & Hsieh, 1997;Lin et al, 2000;Pant & Trenerry, 1995;Waldron & Li, 1996;Han et al, 2008;Hsu et al, 2014;Sun et al, 2014;Li et al, 2015;Aung & Pyell 2016), only a few of them reported benzoic and sorbic acids together in real samples.…”