Ultrasensitive determination of organotin compounds in plastic food packaging and edible oils by sheathless capillary electrophoresis-electrospray ionization-mass spectrometry

An alternative silicone-based passive sampling device to derive organotin concentrations in the aqueous phase

Organotin compounds (OTs) are well studied in various environmental compartments, with a critical focus on the water column as their primary entry point into aquatic ecosystems. In this context, a method for the analysis of organotin (OTs) in water using silicone rubber-based passive sampling was optimized, validated, and field-tested. Validation covered crucial parameters, including the limit of detection (LOD), limit of quantification (LOQ), accuracy, precision, linearity, and matrix effect. The method was shown to be robust (R2 ≥ 0.99), with recoveries between 70.2 and 114.6%, and precise (CV < 12.8%) (N = 3). LODCw and LOQCw were ≤15 and ≤ 48 pg Sn L-1, respectively, for TBT and TPhT. The matrix effect showed to be low (>-20% ME < 20%) for all OTs but TPhT (69.4%). The silicone rubber-water partition coefficients (Log Ksr,w) were estimated at 3.37 for MBT, 3.77 for DBT, 4.17 for TBT, 3.49 for MPhT, 3.83 for DPhT, and 4.22 for TPhT. During the field study carried out between October 2021 and February 2022 at the entrance of the Port of Santos navigation channel (Southeastern Brazil), sampling rates ranged between 4.1 and 4.6 L d-1, and the equilibrium was achieved for MBT, DBT, MPhT, and DPhT after ∼45 days of deployment. The freely dissolved concentrations varied between 134 and 165 pg Sn L-1 for TBT, 388 and 610 pg Sn L-1 for DBT, and 1114 and 1509 pg Sn L-1 for MBT, while MPhT, DPhT, and TPhT were below the limit of detection. Results pointed out that J-FLEX® rubber-based passive sampling is a suitable and reliable alternative method for the continuous monitoring of OTs in the water column.

Advanced detection tools in food fraud: A systematic review for holistic and rational detection method based on research and patents

Modern food chain supply management necessitates the dire need for mitigating food fraud and adulterations. This holistic review addresses different advanced detection technologies coupled with chemometrics to identify various types of adulterated foods. The data on research, patent and systematic review analyses (2018-2023) revealed both destructive and non-destructive methods to demarcate a rational approach for food fraud detection in various countries. These intricate hygiene standards and AI-based technology are also summarized for further prospective research. Chemometrics or AI-based techniques for extensive food fraud detection are demanded. A systematic assessment reveals that various methods to detect food fraud involving multiple substances need to be simple, expeditious, precise, cost-effective, eco-friendly and non-intrusive. The scrutiny resulted in 39 relevant experimental data sets answering key questions. However, additional research is necessitated for an affirmative conclusion in food fraud detection system with modern AI and machine learning approaches.

Occupational exposure to organotin substances: Development of a liquid chromatographic separation method for 11 organotin compounds in workplace air samples via HPLC-ICP-MS

Organotin compounds (OTCs) are widely regulated but rank among the most used organometallic compounds in various industrial sectors. They are significantly more toxic than inorganic tin compounds. At workplaces, OTCs can be released as vapors or dust particles and can be absorbed by inhalation or skin contact. Occupational exposure thus represents a great risk for the absorption of OTCs for employees. Methods for OTCs speciation in workplace air monitoring currently do not exist. This study describes the development of a separation method for eleven in Germany regulated OTCs via HPLC-ICP-MS. The method allows a near baseline separation of MMT, MBT, MOT, MPhT, DMT, DBT, DPhT, TMT, TBT, TPhT and TTMT within 22 min on a C18 column and a ternary solvent and flow rate gradient using methanol, acetonitrile, and ultrapure water + 6% (v/v) acetic acid + 0.17% (m/v) α-tropolone. Ten analytes show linearity in the working range of 10 - 100 µg OTCs/L with R² > 0.999. Due to its high volatility the analyte TTMT showed a quadratic relationship between concentration and signal intensity with R² = 0.9998. The determination of the instrumental limits resulted in detection limits between 0.14 and 0.57 µg Sn/L and limits of quantification between 0.49 and 1.97 µg Sn/L. Over the course of this study thermal instability and cross reactivity of OTC in solution became apparent. Formation of two reaction products in mixed OTCs solutions have been observed. These effects will further be examined within development of appropriate sampling and sample preparation for workplace air to provide a suitable method for the determination of OTCs at workplaces according to normative references.

Recent progress and perspectives of metal organic frameworks (MOFs) for the detection of food contaminants

Over the past decades, increasing research in metal-organic frameworks (MOFs) being a large family of highly tunable porous materials with intrinsic physical properties, show propitious results for a wide range of applications in adsorption, separation, electrocatalysis, and electrochemical sensors. MOFs have received substantial attention in electrochemical sensors owing to their large surface area, active metal sites, high chemical and thermal stability, and tunable structure with adjustable pore diameters. Benefiting from the superior properties, MOFs and MOF-derived carbon materials act as promising electrode material for the detection of food contaminants. Although several reviews have been reported based on MOF and its nanocomposites for the detection of food contaminants using various analytical methods such as spectrometric, chromatographic, and capillary electrophoresis. But there no significant review has been devoted to MOF/and its derived carbon-based electrodes using electrochemical detection of food contaminants. Here we review and classify MOF-based electrodes over the period between 2017 and 2022, concerning synthetic procedures, electrode fabrication process, and the possible mechanism for detection of the food contaminants which include: heavy metals, antibiotics, mycotoxins, and pesticide residues. The merits and demerits of MOF as electrode material and the need for the fabrication of MOF and its composites/derivatives for the determination of food contaminants are discussed in detail. At last, the current opportunities, key challenges, and prospects in MOF for the development of smart sensing devices for future research in this field are envisioned.

Assessing the ecotoxicity of combined exposure to triphenyltin and norfloxacin at environmental levels: A case study of immunotoxicity and metabolic regulation in carp (Cyprinus carpio)

This paper evaluates the coexistence risks of triphenyltin (TPT) and norfloxacin (NOR) to aquatic organisms in the aquatic environment. Carp (Cyprinus carpio) was used as the test organism, the control and exposure groups (1 μg/L TPT), 1 mg/L (NOR), 1 μg/LTPT+1 mg/LNOR (TPT_NOR)) were set up according to the environmental concentration in the severely polluted area for 42 days. The single/combined toxic effects of TPT and NOR on aquatic organisms were evaluated by analyzing carp brain transcriptome sequencing, gut microbiota structure, and detection of biochemical indicators and RT-qPCR. Our results show that TPT and NOR induce lipid metabolism disorder in carp brain tissue, affecting the metabolism of cytochrome P450 to exogenous substances, and NOR also induces immunosuppression in carp. Long-term exposure to TPT combined with NOR amplifies the monotoxicity of TPT or NOR on lipid metabolism and immunosuppression in carp, induces immune dysfunction in brain tissue and changes in gut microbiota structure. However, TPT_NOR has no obvious neurotoxicity on the brain, but it can inhibit the level of intestinal MDA. This highlights that co-exposure of TPT and NOR amplifies metabolic disorders and immunosuppressive functions in carp.

Open Tubular Capillary Electrochromatography-Mass Spectrometry for Analysis of Underivatized Amino Acid Enantiomers with a Porous Layer-Gold Nanoparticle-Modified Chiral Column

By developing a novel chiral column, we integrate open tubular capillary electrochromatography into sheathless mass spectrometry (MS) for efficient analysis of underivatized amino acid enantiomers. The chiral column is easily fabricated by modifying the inner surface of a capillary with a three-dimensional porous layer (PL, thickness ∼ 90 nm, pore size ∼ 30 nm) and gold nanoparticles and by introducing a chiral selector, thiol β-cyclodextrin (SH-β-CD), onto the modified surface via Au-S bonds. This approach greatly enhances the specific surface area and thus the ratio of the stationary phase to mobile phase and interaction between the stationary phase and analytes. The proposed PLOT@Au@CD column is coupled to the sheathless CE-ESI-MS system for chiral analysis of amino acid enantiomers. No derivatization of amino acids is required for chiral analysis, and baseline separation of a total of 15 pairs of amino acid enantiomers is achieved within 17 min with high column efficiencies of 5.60 × 10⁴ to 1.82 × 10⁶ N/m, high resolutions of 1.51-10.0, and low limits of detection between 0.02 and 0.09 μg/mL. The separation efficiency and MS intensity are only slightly decreased over 60 runs or after usage for 15 days, showing excellent repeatability and stability of the PLOT@Au@CD column. The proposed method is successfully applied to the determination of amino acid enantiomers in vinegar samples with satisfactory accuracy. Our study provides a new approach for developing a chiral stationary phase in the chromatographic separation technique, which can be easily coupled to sensitive MS detection, thus it would be of value for various applications in the fields of chiral analysis.

Applications of capillary electrophoresis in the fields of environmental, pharmaceutical, clinical and food analysis (2019-2021)

So far, the potential of capillary electrophoresis (CE) in the application fields has been increasingly excavated due to the advantages of simple operation, short analysis time, high-resolution, less sample consumption and low cost. This review examines the implementations and advancements of CE in different application fields (environmental, pharmaceutical, clinical and food analysis) covering the literature from 2019 to 2021. In addition, ultrasmall sample injection volume (nanoliter range) and short optical path lead to relatively low concentration sensitivity of the most frequently used UV-absorption spectrophotometric detection, so the pretreatment technology being developed has been gradually utilized to overcome this problem. Despite the review is focused on the development of CE in the fields of environmental, pharmaceutical, clinical and food analysis, the new sample pretreatment techniques of microextraction and enrichment which fit excellently to CE in recent three years are also described briefly. This article is protected by copyright. All rights reserved.

Electrospun Coaxial Fibers to Optimize the Release of Poorly Water-Soluble Drug

In a drug delivery system, the physicochemical properties of the polymeric matrix have a positive impact on the bioavailability of poorly water-soluble drugs. In this work, monolithic F1 fibers and coaxial F2 fibers were successfully prepared using polyvinylpyrrolidone as the main polymer matrix for drug loading and the poorly water-soluble curcumin (Cur) as a model drug. The hydrophobic poly (3-hydroxybutyric acid-co-3-hydroxyvaleric acid) (PHBV) was designed as a blank layer to change the hydrophilicity of the fiber and restrain the drug dissolution rate. The curved linear morphology without beads of F1 fibers and the straight linear morphology with few spindles of F2 fibers were characterized using field-emission environmental scanning electron microscopy. The amorphous forms of the drug and its good compatibility with polymeric matrix were verified by X-ray diffraction and attenuated total reflectance Fourier transformed infrared spectroscopy. Surface wettability and drug dissolution data showed that the weaker hydrophilicity F2 fibers (31.42° ± 3.07°) had 24 h for Cur dissolution, which was much longer than the better hydrophilic F1 fibers (15.31° ± 2.79°) that dissolved the drug in 4 h.

The organotin contaminants in food: Sources and methods for detection: A systematic review and meta-analysis

Organotin compounds in low doses have toxic effects. These components may contaminate food. The aim of this systematic review was to determine the type and level of organotin in food that are mainly contaminated with these compounds, as well as common detection methods. The research studies with keywords Organotin, Tributyltin, TBT, Food, Detection, Contamination, and Pollution were searched in PubMed, Scopus, Science Direct, and Google Scholar databases, regardless of publication time. Two author independently investigated the publications. A number of 123 studies were obtained and only 9 articles were finally selected according to exclusion and inclusion criteria. Studies were selected which organotin components were detected in the food matrix. The important data were extracted. Meta-analysis was calculated for the amount of TBT in seafood. The most important of these compounds are TBT, TPhT, Dibutyltin (DBT) and di-n-octyltin (DOT). Surveys were conducted on three continents, Europe, America and Asia. Contaminated foods reportedly included seafood and edible oils, according to studies. TBT was investigated more than other tin components in food. The overall average estimate for TBT in seafood was estimated at 182.33 ng/g that This amount was more than maximum limit. Therefore, it is necessary to take measures to treat the wastewater so that these harmful compounds do not reach the water of sea.