Tracking Aromatic Amines from Sources to Surface Waters

This review examines the environmental occurrence and fate of aromatic amines (AAs), a group of environmental contaminants with possible carcinogenic and mutagenic effects. AAs are known to be partially responsible for the genotoxic traits of industrial wastewater (WW), and AA antioxidants are acutely toxic to some aquatic organisms. Still, there are gaps in the available data on sources, occurrence, transport, and fate in domestic WW and indoor environments, which complicate the prevention of adverse effects in aquatic ecosystems. We review key domestic sources of these compounds, including cigarette smoke and grilled protein-rich foods, and their presence indoors and in aquatic matrices. This provides a basis to evaluate the importance of nonindustrial sources to the overall environmental burden of AAs. Appropriate sampling techniques for AAs are described, including copper-phthalocyanine trisulfonate materials, XAD resins in solid-phase extraction, and solid-phase microextraction methods, which can offer insights into AA sources, transport, and fate. Further discussion is provided on potential progress in the research of AAs and their behavior in an aim to support the development of a more comprehensive understanding of their effects and potential environmental risks.

Synthesis of stable and efficient amide-based covalent organic frameworks fiber coatings for the improved solid-phase microextraction of polar aromatic amines

BACKGROUND

Developing facile and general functionalization strategies to improve the durability of covalent organic framework (COF) coatings and their affinity for polar targets is of great significance for solid-phase microextraction (SPME) technology.

RESULTS

In this work, a facile and general amidation strategy was developed for conversion from reversible (imine) to irreversible (amide) linkages in COF coatings. After the amidation, the durability of the obtained amide-linked covalent organic framework (Am-P-COF) coating was greatly improved, and the adsorption efficiency for polar aromatic amines (AAs) was also significantly increased. Moreover, this strategy is also applicable to the amidation of other two COF coatings, showing good general applicability. The obtained Am-P-COF coated fiber was used for SPME, and then coupled with gas chromatography tandem mass spectrometry (GC-MS/MS) to detect AAs. Under the optimal SPME conditions (extraction temperature: 50 °C, extraction time: 30 min, stirring rate: 600 rpm, pH: 8, NaCl concentration: 5.0 mg mL-1, desorption temperature: 290 °C and desorption time: 10 min), a detection method for trace AAs was established. The established method possess wide linear ranges (0.5-500.0 ng L-1), good correlation coefficients (0.9986-0.9993) and low detection limits (0.1-0.5 ng L-1). Moreover, the established method had also been successfully applied to detection of trace AAs in bottled tea beverage and plastic bags packed tea with satisfactory recoveries (83.5 %-116.8 %).

SIGNIFICANCE AND NOVELTY

This research provides a facile and general pathway for increasing the durability of COF coatings and affinity to the polar AAs. The detection method based on the obtained fibers possesses high sensitivity, satisfactory reproducibility and good precision.

Electrospun polyamide/graphene oxide/polypyrrole composite nanofibers: an efficient sorbent for headspace solid phase microextraction of methamphetamine in urine samples followed by GC-MS analysis

A novel polyamide/graphene oxide/polypyrrole nanofiber was fabricated with the aid of the electrospinning technique and applied in headspace solid phase microextraction.

Recent Applications and Newly Developed Strategies of Solid-Phase Microextraction in Contaminant Analysis: Through the Environment to Humans

The present review aims to describe the recent and most impactful applications in pollutant analysis using solid-phase microextraction (SPME) technology in environmental, food, and bio-clinical analysis. The covered papers were published in the last 5 years (2014–2019) thus providing the reader with information about the current state-of-the-art and the future potential directions of the research in pollutant monitoring using SPME. To this end, we revised the studies focused on the investigation of persistent organic pollutants (POPs), pesticides, and emerging pollutants (EPs) including personal care products (PPCPs), in different environmental, food, and bio-clinical matrices. We especially emphasized the role that SPME is having in contaminant surveys following the path that goes from the environment to humans passing through the food web. Besides, this review covers the last technological developments encompassing the use of novel extraction coatings (e.g., metal-organic frameworks, covalent organic frameworks, PDMS-overcoated fiber), geometries (e.g., Arrow-SPME, multiple monolithic fiber-SPME), approaches (e.g., vacuum and cold fiber SPME), and on-site devices. The applications of SPME hyphenated with ambient mass spectrometry have also been described.

Amphiphilic calix[4]arenes as a highly selective gas chromatographic stationary phase for aromatic amine isomers

Efficient separation of aromatic amine isomers is a challenging issue in chemical industry and environmental analysis. Here we report the use of p-amino-tetradecyloxy-calix[4]arene (C4A-NH₂) as a novel stationary phase for gas chromatographic (GC) separations. The statically coated C4A-NH₂ capillary column showed a high column efficiency of 4332 plates/m for a 0.25 mm ID column and medium polarity. The C4A-NH₂ stationary phase exhibited an excellent separation performance both for aromatic amine isomers and a complex mixture of aliphatic analytes with a wide ranging polarity, showing distinct advantages over the commercial polysiloxane stationary phases via diversified molecular interactions covering H-bonding, π-π, van der Waals interactions and shape-fitting selectivity. The retention mechanisms of aromatic amine isomers on C4A-NH₂ column were further investigated by quantum chemistry calculations. In addition, the C4A-NH₂ column showed good column repeatability with relative standard deviation (RSD) values of 0.03%-0.07% for run-to-run, 0.10%-0.27% for day-to-day and 2.6%-5.7% for column-to-column, respectively, and thermal stability up to 240℃.

Determination of trace amounts of aromatic amines after magnetic solid-phase extraction using silver-modified Fe3 O4 /graphene nanocomposite

In this work, a fast and simple magnetic dispersive solid phase extraction methodology was developed utilizing Ag@magnetite nanoparticles@graphene nanocomposite as an efficient magnetic nanosorbent for preconcentration and determine of five aromatic amines in water samples. The sorbent was characterized by diverse characterization techniques. After the extraction, high-performance liquid chromatography with UV detection was utilized to analysis the aromatic amines. The effects of different factors on the extraction process were studied thoroughly via design of experiment and desirability function. Detection limits and linear dynamic ranges were obtained in the range of 0.10-0.20 and 0.3-300 μg/L, respectively. The relative standard deviations (n = 5) were in the range of 4.3-6.5%. Eventually, the method was employed for determination of target aromatic amines in various water samples.

Efficient enrichment of triazole fungicides from fruit and vegetable samples by a spherical porous aromatic framework

A porous aromatic framework was synthesized and utilized as a novel SPME coating for efficient enrichment of triazole fungicides.