Ionic Liquid Modified Porous Polymer as a Dispersive Filter Extraction Adsorbent for Simple, Sensitive, and Efficient Determination of Chlorotriazine Herbicides in Irrigation Water

Molecularly imprinted resin modified with ionic liquid for dispersive filter extraction and determination of perfluoroalkyl acids in eggs

Perfluoroalkyl acids (PFAAs) are emerging pollutants that endangers food safety. Developing methods for the selective determination of trace PFAAs in complex samples remains challenging. Herein, an ionic liquid modified porous imprinted phenolic resin-dispersive filter extraction-liquid chromatography-tandem mass spectrometry (IL-PIPR-DFE-LC-MS/MS) method was developed for the determination of perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) in eggs. The new IL-PIPR adsorbent was prepared at room temperature, which avoids the disorder and instability of the template at high temperatures. The imprinting factor of IL-PIPR for PFOA and PFOS exceeded 7.3. DFE, combined with IL-PIPR (15 mg), was used to extract PFOA and PFOS from eggs within 15 min. The established method exhibits low limits of detection (0.01-0.02 ng/g) and high recoveries (84.7%-104.7%), which surpass those of previously reported methods. This work offers a new approach to explore advanced imprinted adsorbents for PFAAs, efficient sample pretreatment technique, and analytical method for pollutants in foods.

Development of a three-dimensional porous ionic liquid-chitosan-graphene oxide aerogel for efficient extraction and detection of polyhalogenated carbazoles in sediment samples

The three-dimensional porous ionic liquid-chitosan-graphene oxide aerogel (IL-CS-GOA) monolithic adsorbent with a through-hole structure was prepared using natural chitosan (CS) as the skeletal framework, graphene oxide (GO) as the support to provide mechanical strength, and ionic liquid (IL) as the porogen and modifier. The resulting IL-CS-GOA demonstrated a fluffy and porous structure with various pore sizes and excellent regeneration capability (over six cycles). Its specific surface area exceeded that of CS-GOA and IL-GOA by more than 7 times, enhancing its polyhalogenated carbazoles (PHCZs) adsorption capacity. Within 5 min, IL-CS-GOA (1.0 mg) exhibited adsorption amounts of 539 ng mg-1 for 3-bromocarbazole (3-BCZ), 716 ng mg-1 for 2,7-dibromocarbazole (2,7-BCZ), and 798 ng mg-1 for 1,3,6,8-tetrabromocarbazole (1,3,6,8-BCZ), showcasing its rapid mass transfer and high adsorption capabilities. IL-CS-GOA was utilized as the adsorbent for glass dropper extraction (GDE) in conjunction with gas chromatography-mass spectrometry (GC-MS/MS), to develop a highly efficient and accurate method for determining PHCZs in sediments. Under optimal conditions, the established method exhibited a wide linear range (0.4-250 ng g-1, r ≥ 0.9990), low detection limits (0.04-0.24 ng g-1), and satisfactory recoveries (80.5 %-93.8 %), enabling the accurate and rapid detection of PHCZs in sediment samples. This study presents a novel approach for creating three-dimensional porous aerogels, introduces a new form of sample pretreatment using GDE with a monolithic adsorbent, and offers a new method for the determination of PHCZs in environmental matrices.

A Carboxyl Group-Functionalized Ionic Liquid Hybrid Adsorbent for Solid-Phase Extraction and Determination of Trace Diclofenac Sodium in Milk Samples

A simple and efficient sample pretreatment technology is very important for the accurate determination of trace drug residues in foods to ensure food safety. Herein, we report a new carboxyl group-functionalized ionic liquid hybrid solid- phase adsorbent (PS-IL-COOH) for the highly efficient extraction and quantitative determination of diclofenac sodium (DS) residue in milk samples. It was found that the adsorption efficiency of PS-IL-COOH for the ppb level of DS was greater than 93.0%, the adsorption capacity was 934.1 mg/g, and the enrichment factor was 620.0, which surpass most of the previously reported values for DS adsorbents. The high concentration of salts did not interfere with the adsorption of DS. Importantly, the recovery of DS was above 90% after 16 adsorption--regeneration cycles. The synergistic effect of the multiple interactions was found to be the main factor for the high efficiency of DS adsorption. The proposed method was applied to the extraction and detection of DS in milk samples, with the relative recovery ranging from 88.2 to 103.0%.

Dual-template hydrophilic imprinted resin as an adsorbent for highly selective simultaneous extraction and determination of multiple trace plant growth regulators in red wine samples

In recent years, numerous plant growth regulators have been found in foods and have a toxicity to human health, so its simultaneous multiple monitoring is urgently. For the first time, a rapid, accurate, and high-selective method was established to extract and determine multiple plant growth regulators simultaneously in red wines using a new dual-template hydrophilic molecularly imprinted resin (DHMIR) as an adsorbent of pipette tip solid-phase extraction coupled with HPLC. The as-prepared DHMIR combined the advantages of the hydrophilicity of hydrophilic resin and multi-imprinted recognition of dual-template molecular imprinting, overcoming the poor imprinted recognition ability of traditional imprinting materials in water and low extraction efficiency to multiple targets. Under the optimized conditions, the proposed method exhibited high sensitivity (2.29-3.94 ng mL^-1) and recoveries (80.9-109.0 %) using only 15 mg DHMIR. This study provides an effective strategy for rapid, accurate, low-cost, and high-selective determination of the multiple analytes in food samples.

Ant nest-like hierarchical porous imprinted resin-dispersive solid-phase extraction for selective extraction and determination of polychlorinated biphenyls in milk

Polychlorinated biphenyls (PCBs) are persistent toxic, organic chemicals that tend to accumulate in the food chain. This study reports the rapid and selective extraction and determination of PCBs (PCB81, 153, 105, 126, and 157) in milk samples by a dispersive solid-phase extraction (DSPE) coupled with gas chromatography-tandem mass spectrometry (GC-MS/MS). An ionic liquid-molecularly imprinted porous resin (IL-MIPPR) as a DSPE adsorbent was synthesized from m-aminophenol, formaldehyde, and 2,2'-benzidinedisulfonic acid as the monomer, crosslinker, and virtual template, respectively. The IL-MIPPR had a fast mass transfer (1.0 min) and good selectivity (imprinting factors of 1.8-3.0). The IL-MIPPR - DSPE - GC-MS/MS method exhibited good linearity (R² ≥ 0.9995), the limit of detections (LODs) < 0.6 pg/g, and the recoveries ranged from 82.8 % to 106 % with relative standard deviations ≤ 6.6 %. This method is thus better than previously reported methods in terms of the LOD, the adsorbent dosage, and the extraction time.

Identifying unusual human exposures to pesticides: Qilu Lake Basin as an overlooked source

Although common exposure pathways of pesticides (e.g., crop consumption) have been intensively studied, we noticed that some unusual occupational exposures to pesticides were overlooked and could lead to unacceptable health risks. In this study, we presented information on the occurrence of 5 triazine pesticides (TRIs) and 3 neonicotine pesticides (NEOs) detected in water samples of Qilu Lake Basin in China. We identified the unusual occupational exposure scenarios as (i) adult females washing the harvested vegetables, and (ii) adult males catching fish in Qilu Lake; next, the health risk assessment was conducted using collected data. The results showed that the mean Σ5 TRI concentrations ranged from 505.87 ng/L in spring to 864.04 ng/L in summer, and the river water samples around Qilu Lake had the highest concentrations. The mean concentrations of Σ3 NEOs ranged from 885.86 ng/L in winter to 2593.04 ng/L in summer. Occupational exposed populations were bearing one to two orders of magnitude higher exposure doses than local adults. Although the carcinogenic risks caused by atrazine in water were at acceptable levels for local residents, all the occupational exposed males were at moderate risks, and 15.78 %-43.50 % of occupational exposed females in different seasons were even at high risks. The non-carcinogenic risks caused by pesticides in water were all at negligible levels, but the occupational exposed population were facing up to two orders of magnitude higher risks than local residents. This study established a sound basis for further decision-making to take necessary action on protection of sensitive population groups.

Molecularly imprinted monolith-based portable in-tip microextraction device for field specific extraction of triazine herbicides in aqueous samples followed by chromatographic quantification

Field selective extraction is crucial for accurate monitoring of triazine herbicides (TAHs) in aqueous samples. For this purpose, using atrazine as template and 3-acrylamido phenylboronic acid as functional monomer which was quickly screened with calculation simulation technology, a new molecularly imprinted monolith-based adsorbent (MBA) was fabricated and utilized as the extraction phase of laboratory-made multichannel in-tip microextraction device (MIMD). A series of techniques were adopted to characterize the physical and chemical properties of the synthesized MBA. Under the optimized preparation conditions, the recognition factor and capture capacity of MBA towards atrazine were as high as 2.9 and 23.4 mg/g, respectively, and the enrichment factors towards TAHs located in the range of 276-359. The study about adsorption isotherm evidenced the adsorption of MBA towards atrazine was fit for Freundlich adsorption model. Under the beneficial extraction parameters, the introduced MBA/MIMD was utilized to on-site extract TAHs in a variety of aqueous samples prior to HPLC determination. High sensitivity (limit of detection: 0.25-0.64 ng/L), good precision (relative standard deviation: 1.4-9.5%) and satisfying recovery (81.0-113%) were achieved. Accuracy and reliability of the introduced method were inspected through confirmation experiments. Owing to the good results and outstanding merits, the established MBA/MIMD technique is appropriate for field sample preparation of TAHs and the developed method can be utilized to monitor TAHs residuals in various aqueous samples.

Green synthesis of phloroglucinol-urotropine porous polymer: Ingenious miniaturized solid phase extraction for efficient purification and determination of polycyclic aromatic hydrocarbons in lotus roots

Polycyclic aromatic hydrocarbons (PAHs) posed a serious threat to food safety and human health due to long-term emission. In this work, a new method was established using phloroglucinol-urotropine porous polymer (PU-PP) in a pipette tip for solid phase extraction (PT-SPE) for the first time and used prior to determination of four PAHs (phenanthrene, anthracene, fluoranthene, and pyrene) in lotus roots. Synthesis of the PU-PP adsorbent was green compared with alternatives; urotropine was used as a cross-linker and ethanol-water as the solvent. PU-PP-based PT-SPE had the advantages of low solvent consumption, good purification, practicability, stability, and low-cost. The proposed pre-purification method offered low limits of detection (0.09-0.28 ng/g) and good recoveries (84.6-114.3 %, RSDs ≤ 5.6 %) for determination of the four PAHs, which were detected at trace concentrations in samples. This new method provides an alternative for monitoring trace pollutants in aquatic plant ingredients.

Magnetic phenolic resin core-shell structure derived carbon microspheres for ultrafast magnetic solid-phase extraction of triazine herbicides

In this study, monodisperse magnetic carbon microspheres were successfully synthesized through the carbonization of phenolic resin encapsulated Fe₃ O₄ core-shell structures. The magnetic carbon microspheres showed high performance in ultrafast extraction and separation of trace triazine herbicides from environmental water samples. Under optimized conditions, both the adsorption and desorption processes could be achieved in 2 min, and the maximum adsorption capacity for simazine and prometryn were 387.6 and 448.5 μg/g. Coupled with HPLC-UV detection technology, the detection limit of triazine herbicides was in the range of 0.30-0.41 ng/mL. The mean recoveries ranged from 81.44 to 91.03% with relative standard deviations lower than 7.47%. The excellent magnetic solid phase extraction performance indicates that magnetic carbon microspheres are promising candidate adsorbent for the fast analysis of environmental contaminants. This article is protected by copyright. All rights reserved.