Determination of Fluorescent Whitening Agents in Paper Materials by Ion-Pair Reversed-Phase High-Performance Liquid Chromatography

J of Separation Science

Xiao

et al. 2018

Magnetic solid-phase extraction is a powerful sample preparation tool. Combined with covalent organic polymers, this technique permits an excellent extraction performance. We present a sensitive, efficient, and easy operating magnetic- covalent organic polymer solid-phase extraction method. By using the magnetic covalent organic polymer nanoparticles yielded by a one-pot reaction, five fluorescent whitening agents were successfully preconcentrated and separated. The saturated extraction amounts of the magnetic covalent organic polymer nanoparticles for the five fluorescent whitening agents were in the range of 97-155 nmol/mg. Coupled with high-performance liquid chromatography, the limit of detection of the fluorescent whitening agent was improved by at least an order of magnitude compared to current literature records. Under the optimal conditions, the linear ranges of these five fluorescent whitening agents were up to 0.5-100 ng/L, the limit of detection was as low as 0.1 ng/L, and the recoveries were in the range of 78.2-105% with relative standard deviations lower than 5.5%. Meanwhile, a trace level of 7-diethylamino-4-methylcoumarin was found in a typical cosmetic sample by using this magnetic-covalent organic polymer solid-phase extraction method when coupling with high-performance liquid chromatography. Moreover, this sensitive, efficient, and easy operating sample preparation method can be extended to analysis of other analytes that have a π-π conjugated structure.

Section: Application In Cosmetic Samplesmentioning

confidence: 97%

Magnetic‐covalent organic polymer solid‐phase extraction coupled with high‐performance liquid chromatography for the sensitive determination of fluorescent whitening agents in cosmetics

Xia

J of Separation Science

Xiao

et al. 2018

Simultaneous determination of 11 fluorescent whitening agents in food‐contact paper and board by ion‐pairing high‐performance liquid chromatography with fluorescence detection

Jiang

J of Separation Science

et al. 2015

4,4'-Diaminostilbene-2,2'-disulfonic acid based fluorescent whitening agents (DSD-FWAs) are prohibited in food-contact paper and board in many countries. In this work, a reliable high-performance liquid chromatography method was developed for the simultaneous determination of 11 common DSD-FWAs in paper material. Sample preparation and extraction as well as chromatographic separation of multicomponent DSD-FWAs were successfully optimized. DSD-FWAs in prepared samples were ultrasonically extracted with acetonitrile/water/triethylamine (40:60:1, v/v/v), separated on the C(18) column with the mobile phase containing tetrabutylammonium bromide, and then detected by a fluorescence detector. The limits of detection were 0.12-0.24 mg/kg, and the calibration curves showed the linear correlation (R(2) ≥ 0.9994) within the range of 8.0-100 ng/mL, which was equivalent to the range of 0.80-10 mg/kg in the sample. The average recoveries and the RSDs were 81-106% and 2-9% at two fortification levels (1.0 and 5.0 mg/kg) in paper bowls, respectively. The successful determination of 11 DSD-FWAs in food-contact paper and board obtained from local markets indicated that the newly developed method was rapid, accurate, and highly selective.

Environmental impact on the light and perspiration stability of triazinylstilbene fluorescent brighteners on cotton fabrics

Zhao

et al. 2014

Fibers Polym

The fading of the triazinylstilbene fluorescent brighteners (TFBs) on cotton fabric under the conditions of exposure to sunlight and human sweat may reduce the visual quality and added value of the garment and also produce many toxic substances, which could threaten human health due to direct contact with skin. In order to investigate the light-fastness and perspiration stability of TFBs on cotton fabrics, three environmental factors of affecting the photo-fading of TFBs, i.e., ultraviolet irradiation, wet condition, and atmospheric constituents, were discussed according to AATCC standard. The results indicated that the effect of ultraviolet irradiation was more significant than its visible counterpart on the light and perspiration stability of TFBs on cotton fabrics. The light stability of TFBs was susceptible to the wet environment, and the presence of moisture accelerated the rate of photo-fading of TFBs. Furthermore, the study on the contribution of atmospheric constituents disclosed that the oxygen in the air together with the moisture of perspiration would make the synergistic effect on the fading of TFBs.