Determination of phthalic acid esters in Chinese white spirit using dispersive liquid-liquid microextraction coupled with sweeping β-cyclodextrin-modified micellar electrokinetic chromatography

Recent advancements in the extraction and analysis of phthalate acid esters in food samples

Phthalate acid esters (PAEs) are ubiquitous environmental pollutants present in food samples, necessitating accurate detection for risk assessment and remediation efforts. This review provides an updated overview of the recent progress on the PAEs analysis regarding sample pretreatment techniques and analytical methodologies over the latest decade. Advances in sample preparation include solid-based extraction techniques replacing conventional liquid-liquid extraction, with solid sorbents emerging as promising alternatives due to their minimal solvent consumption and enhanced selectivity. Although techniques like the microextraction methods offer versatility and reduced solvent reliance, there is a need for more efficient and environmentally friendly techniques enabling on-site portable detection. High-resolution mass spectrometry is increasingly utilized for its enhanced sensitivity and reduced contamination risks. However, challenges persist in developing in situ analytical techniques for trace PAEs in complex food samples. Future research should prioritize novel analytical techniques with superior sensitivity and selectivity, addressing current limitations to meet the demand for precise PAEs detection in diverse food matrices.

Unpacking Phthalates from Obscurity in the Environment

Phthalates (PAEs) are a group of synthetic esters of phthalic acid compounds mostly used as plasticizers in plastic materials but are widely applied in most industries and products. As plasticizers in plastic materials, they are not chemically bound to the polymeric matrix and easily leach out. Logically, PAEs should be prevalent in the environment, but their prevalence, transport, fate, and effects have been largely unknown until recently. This has been attributed, inter alia, to a lack of standardized analytical procedures for identifying them in complex matrices. Nevertheless, current advancements in analytical techniques facilitate the understanding of PAEs in the environment. It is now known that they can potentially impact ecological and human health adversely, leading to their categorization as endocrine-disrupting chemicals, carcinogenic, and liver- and kidney-failure-causing agents, which has landed them among contaminants of emerging concern (CECs). Thus, this review article reports and discusses the developments and advancements in PAEs' standard analytical methods, facilitating their emergence from obscurity. It further explores the opportunities, challenges, and limits of their advancements.

Method development of stir bar sportive extraction coupled with thermal desorption-gas chromatography-mass spectrometry for the analysis of phthalates in Peruvian pisco

In this work, for the first time, a stir bar sorptive extraction (SBSE) coupled with thermal desorption-gas chromatography-mass spectrometry (TD-GC-MS) was developed and validated for the determination of seven phthalates in Peruvian pisco. The phthalate compounds considered were dimethyl phthalate (DMP), diethyl phthalate (DEP), bis(2-ethylhexyl) hexahydrophthalate (BEHP), benzyl butyl phthalate (BBP), di-n-butyl phthalate (DBP), di-isodecyl phthalate (DIDP) and di-isobutyl phthalate (DIBP). The best overall analytical conditions obtained from the optimization were as follow: extraction time of 120 min, size of polydimethylsiloxane (PDMS) twister (20 mm length x 1 mm thickness), NaCl content (20 %) and sample volume (40 mL). The in-house validation of SBSE/TD-GC-MS method was performed taking into account the ISO/IEC 17,025 requirements and EURACHEM/CITAC guideline. Under optimal conditions, very low limits of detection of 1.3-0.21 µg L-1 were obtained. Furthermore, the limits of quantification ranged from 4.2-70 µg L-1, and the correlation coefficients were found to be ≥ 0.991. The method was precise, with relative standard deviations (RSD, %) for inter twister repeatability and the inter day repeatability precisions from 1.1 to 11 and from 6.2 to 15.9, respectively. The pisco samples were analysed with recoveries between 91-124.4%, and DBP, BEHP, and BBP were the most commonly found compounds in the samples. The optimized methodology was also evaluated in terms of green character, and it obtained almost the best AGREE score when it was compared with other previous methods for the analysis of phthalates in alcoholic beverages. Therefore, the SBSE/TD-GC-MS method has proved to be suitable for routine practice because it is simple, less laborious, economical, precise, accurate and green, and it would be applicable for pisco safety regulations.

Nano-liquid chromatography combined with a sustainable microextraction based on natural deep eutectic solvents for analysis of phthalate esters

The separation of 11 phthalic acid ester (PAEs) was carried out by nano-liquid chromatography coupled to ultraviolet and MS detection. Preliminary experiments were achieved in order to select suitable stationary phases and chromatographic conditions. The baseline separation was obtained, for all compounds, with an XBridge^TM C₁₈ column in less than 15 min, working in step gradient mode. The sensitivity of the method was improved by on-column focusing. PAEs were extracted from alcoholic and nonalcoholic beverages using vortex-assisted emulsification dispersive liquid-liquid microextration and natural deep eutectic solvents. The whole method was validated in terms of linearity, sensitivity, precision, recovery, and repeatability. Combination of both off-line sample preparation preconcentration and large injection volume led to obtain LOQs in the range 5-47 ng/mL. The developed nano-LC-UV method was extended to MS detection to confirm the presence of PAEs in some beverages commercialized in different types of packaging.

Development and validation of an ultra high performance liquid chromatography-tandem mass spectrometry method for the determination of phthalate esters in Greek grape marc spirits

An Ultra High Performance Liquid Chromatography - Tandem Mass Spectrometry method has been developed for the analysis of 12 phthalate esters in Greek grape marc spirits. The phthalates were separated on a U-VDSpher PUR 100 C18-E (100 mm x 2.0 mm, 1.8 μm) column by gradient elution. The analytes were ionized by positive electrospray ionization using the multiple reaction monitoring mode. The standard addition method was used for quantification and the Student's t-test was carried out to evaluate the matrix effect. The accuracy of the method was assessed by recovery experiments resulting in values from 81.6 to 109.6%. The detection limits ranged from 0.3 to 33.3 μg L^-1.The proposed method was validated and successfully applied to the analysis of 45 samples collected from Greece and Cyprus. All phthalate esters proved to be present at least once in the analysed grape marc spirits samples, except only in cases of diphenyl phthalate and diisodecyl phthalate, while for the regulated phthalates only bis (2-ethylhexyl) phthalate was quantified above the legislative concentration limits.

Phthalic Acid Ester-Binding DNA Aptamer Selection, Characterization, and Application to an Electrochemical Aptasensor

Phthalic acid esters (PAEs) areone of the major groups of persistent organic pollutants. The group-specific detection of PAEs is highly desired due to the rapid growing of congeners. DNA aptamers have been increasingly applied as recognition elements on biosensor platforms, but selecting aptamers toward highly hydrophobic small molecule targets, such as PAEs, is rarely reported. This work describes a bead-based method designed to select group-specific DNA aptamers to PAEs. The amino group functionalized dibutyl phthalate (DBP-NH2) as the anchor target was synthesized and immobilized on the epoxy-activated agarose beads, allowing the display of the phthalic ester group at the surface of the immobilization matrix, and therefore the selection of the group-specific binders. We determined the dissociation constants of the aptamer candidates by quantitative polymerization chain reaction coupled with magnetic separation. The relative affinities and selectivity of the aptamers to other PAEs were determined by the competitive assays, where the aptamer candidates were pre-bounded to the DBP-NH2 attached magnetic beads and released to the supernatant upon incubation with the tested PAEs or other potential interfering substances. The competitive assay was applied because it provided a facile affinity comparison among PAEs that had no functional groups for surface immobilization. Finally, we demonstrated the fabrication of an electrochemical aptasensor and used it for ultrasensitive and selective detection of bis(2-ethylhexyl) phthalate. This protocol provides insights for the aptamer discovery of other hydrophobic small molecules.

Effective adsorption of phenolic pollutants from water using β-cyclodextrin polymer functionalized Fe3O4 magnetic nanoparticles

β-Cyclodextrin polymer functionalized magnetic nanoparticles possess adsorption properties favorable for the purpose of removing phenolic pollutants.