Ionic liquid based vortex assisted liquid–liquid microextraction combined with liquid chromatography mass spectrometry for the determination of bisphenols in thermal papers with the aid of response surface methodology

A fast and direct determination of bisphenol S in thermal paper samples using paper spray ionization mass spectrometry

Concerns about human health regarding the large use of bisphenol A in thermal papers have led to its replacement by bisphenol S. Analyses of bisphenols require several sample pretreatment steps, which are laborious, expensive, and time-consuming. A paper spray ionization mass spectrometry (PSI-MS) was developed to detect and quantify bisphenol S in three different brands of thermal papers commercially available. Parameters such as paper size, and paper position relative to the mass spectrometer inlet were evaluated. The analyses were performed in selected ion monitoring mode on a linear ion trap mass spectrometer. The developed method presented absolute recovery values ranging from 92.2 to 109.04%, accuracy values from -1.2 to 9.0%, and inter assay precision from 1.8 to 5.6% and enabled LOD as low as 5 ng g^-1. The concentration of bisphenol S in all of the three brands of BPA-free thermal papers evaluated ranged from 1.36 to 6.77 μg g^-1, and the concentrarion of BPA ranged from 6.56 to 16.4 μg g^-1 in all samples of thermal paper evaluated. The PSI-MS method described here was comparable to the conventional ones, such as liquid chromatography coupled with mass spectrometry and gas chromatography coupled with mass spectrometry described in the literature. The present study proved to be practical, fast, and efficient for the direct determination of bisphenol S in thermal papers. Furthermore, the methodology here described showed to be a promising alternative to replace the classical methods for determination of bisphenol S, due to its simplicity, and no needing of any sample pretreatment.

Determination of bisphenol A: Old problem, recent creative solutions based on novel materials

Bisphenol A is a synthetic compound widely used in industry, in the production of polycarbonate, epoxy resins, and thermal paper, among others. Its annual production is estimated at millions of tons per year, demonstrating its importance. Despite its wide application in various everyday products, once in the environment (due to its disposal or leaching), it has high toxicity to humans and animal life, and this problem has been well known for years. Given this problem, many researchers seek alternatives for its monitoring in matrices such as natural water, waste, food, and biological matrices. For this, new advanced materials have been developed, characterized, and applied in creative ways for the preparation of samples for the determination of bisphenol A. This article aims to present some of these important and recent applications, describing the use of molecularly imprinted polymers, metal and covalent organic frameworks, ionic liquids and magnetic ionic liquids, and deep eutectic solvents as creative solutions in sample preparation for the long-standing problem of bisphenol A determination.

The presence of bisphenol A in the thermal paper in the face of changing European regulations - A comparative global research

Bisphenol A (BPA) is used as a color developer in a thermal paper that after a heating process reacts with a leuco dye and changes it to a colored form. Receipts from cash registers are considered as the main source of consumer exposure to bisphenols together with polycarbonates and epoxy resins. Levels of BPA and its possible alternatives were determined in thermal paper samples collected between May 2018 and May 2019 in 22 European and 17 non-European countries on all inhabited continents (220 samples in total, 133 of which were from Europe and 87 from other countries). These measurements were intended to check the level of BPA presence in receipts originating from different countries, especially from Europe in the light of changing regulations restricting its use. The effect of thermal printing on developer content was also analyzed, but no major changes in concentrations of bisphenols were observed during the process. Thus, printed receipts could be used for the determination of bisphenol content. Analysis of receipts from 39 countries has shown that BPA is still the most common compound used around the world with 69% samples containing this color developer. Among other tested bisphenols, BPS was used as a color developer in 20% samples, but it was noted that all samples collected from Japan and the United States of America were found to contain only BPS. Other bisphenols (F, AF, E, and B) considered as possible alternatives for BPA were detected only at trace levels or not detected at all, which showed that they were not used as color developers. The relatively large use of BPS as a BPA substitute is worrying because this compound not only has similar endocrine properties but is also poorly biodegradable. Besides, its relatively high polarity facilitates spreading in the environment.

Toxicity assessment of parabens in Caenorhabditis elegans

Parabens, the alkyl esters of p-hydroxybenzoic acid such as methylparaben (MeP), ethylparaben (EtP), propylparaben (PrP), butylparaben (BuP) are used as a preservative in food, personal care products (PCPs), and pharmaceuticals, due to their antimicrobial properties. Parabens are continuously released into the environment, during washout of PCPs, disposal of industrial waste from the pharmaceutical and paper industries. Parabens have been detected in the indoor dust, wastewater stream, surface water of rivers, and the marine system. Recent eco-toxicological data and the environmental presence of parabens, has raised concerns regarding the safety and health of environment/humans. Thus, to further understand the toxicity of parabens, the present study was carried out in the soil nematode and well established biological model organism Caenorhabditis elegans. In the present study, LC₅₀ of MeP, EtP, PrP and BuP for 72 h exposures from L1 larva to adult stage was found to be 278.1, 217.8, 169.2, and 131.88 μg/ml, respectively. Further exposure to 1/5th of LC₅₀ of parabens yielded an internal concentration ranging from 1.67 to 2.83 μg/g dry weight of the organism. The toxicity of parabens on the survival, growth, behavior, and reproduction of the C. elegans was found in the order of BuP > PrP > EtP > MeP. Worms exposed to parabens show significant down-regulation of vitellogenin genes, high levels of reactive oxygen species and anti-oxidant transcripts, the latter being concordant with nuclear localization of DAF-16 and up-regulation of HSF-1 and SKN-1/Nrf. Hence, parabens caused endocrine disruption, oxidative stress and toxicity in C. elegans at environment relevant internal concentration of parabens.

Dispersive micro-solid phase extraction based on Fe3O4@SiO2@Ti-MOF as a magnetic nanocomposite sorbent for the trace analysis of caffeic acid in the medical extracts of plants and water samples prior to HPLC-UV analysis

In this work, Fe₃O₄@SiO₂@Ti-MOF-NCs, as an efficient sorbent, have been synthesized in a laboratory and utilized for extracting CA in the medical extracts of plants and water samples before their analysis by HPLC.