Covalent immobilization of ionic liquid-based porous polymer onto poly(ether ether ketone) for stir bar sorptive extraction and its application in analysis of chlorophenoxy acid herbicides in soil

Deep Eutectic Solvent Stir Bar Sorptive Extraction: A Rapid Microextraction Technique for the Determination of Vitamin D3 by Spectrophotometry

In this paper, a new microextraction method, named deep eutectic solvent stir bar sorptive extraction (DES-SBSE), is described that utilizes a hydrophobic DES (hDES) as a coating for SBSE. As a model, vitamin D₃ was extracted efficiently by this technique from different real samples before its spectrophotometric determination. A conventional magnet was encapsulated inside a glass bar (1.0 cm × 2 mm) and coated by the hDES consisting of tetrabutylammonium chloride and heptadecanoic acid (mole ratio 1:2). Parameters affecting microextraction were studied and optimized by one-variable-at-a-time, central composite design, and Box-Behnken design methods. Under the optimum conditions, the detection limit of 0.08 μg L^-1 could be reached. The linear range of the method was between 0.5 and 1000.0 μg L^-1 for the analyte. Precision for intraday repeatability and interday reproducibility of the method was better than 3.1 and 4.2, respectively. A single stir bar could be used for at least 50 successive extractions and the batch-to-batch reproducibility of SB coated with hDES was 4.5%.

Fabrication of stable multivariate metal-organic frameworks with excellent adsorption performance toward bisphenols from environmental samples

As a type of environmental endocrine disrupting chemicals, bisphenols (BPs) have a certain embryonic toxicity and teratogenicity, which can significantly increase the risks of breast cancer, prostate cancer, leukemia and other cancers. In this work, stable multivariate metal-organic frameworks (UiO-66-NH₂/TCPP_x) were synthesized via in situ one-pot method and used as miniaturized dispersive solid-phase extraction (dμSPE) sorbents for extraction of trace BPs from environmental samples. The phase purity, crystal morphology and physical properties of UiO-66-NH₂/TCPP_x samples were varied by adjusting the mass ratio of TCPP. The extraction performance of UiO-66-NH₂/TCPP_x samples were investigated and UiO-66-NH₂/TCPP_1.0 exhibited the highest adsorption efficiency. Besides, UiO-66-NH₂/TCPP_1.0 possessed excellent recycling stability for the adsorption and desorption of BPs more than 20 cycles. The experimental parameters including amount of adsorbent, adsorption time, sample solution pH, temperature, desorption time and desorption solvents which affecting the efficiency of dμSPE were studied, respectively. Good linearity (R² > 0.9992) in range of 0.1-200 ng mL^-1 was obtained. The detection limits (S/N = 3) and quantification limits (S/N = 10) were achieved at 0.03-0.08 ng mL^-1 and 0.1-0.5 ng mL^-1, respectively. The relative standard deviations (RSDs) of intra-day and inter-day ranged from 2.5 to 5.5% and 1.1-6.8%. Enrichment factors were calculated in the range of 303-338. The obtained recoveries of bisphenol F (BPF), bisphenol A (BPA), bisphenol B (BPB) and bisphenol AF (BPAF) were 81.26-91.03% (RSDs = 0.96-6.47%), 82.2-97.27% (RSDs = 0.45-6.15%), 87.56-97.26% (RSDs = 1.1-6.22%) and 82.2-100.8% (RSDs = 0.46-4.07%). The UiO-66-NH₂/TCPP_1.0 can be employed as potential dμSPE sorbents for the enrichment of trace BPs in the environmental samples.

Enrichment and Quantitative Determination of Free 3,5- Diiodothyronine, 3',5'-Diiodothyronine, and 3,5-Diiodothyronamine in Human Serum of Thyroid Cancer by Covalent Organic Hyper Cross-linked Poly-ionic Liquid

The incidence of thyroid cancer is increasing worldwide. So far, still no non-invasive clinical test biomarkers were developed for the diagnosis of thyroid cancer. The diiodothyronines (T2s) are precursors and metabolites of thyroid hormone (T4). Some reports predict that T2s may be associated with several thyroid diseases, especially the thyroid cancer. Detecting free T2s in human serum may help the diagnosis of thyroid cancer. However, few works have reported the detection of T2s due to their trace amounts. Here we developed a novel hyper organic cross-linked poly ionic liquid (PIL) material for the enrichment of three main compounds in T2s family, including 3,5- diiodothyronine (3,5-T2), 3',5'-diiodothyronine (3',5'-T2), and 3,5-diiodothyronamine (3,5-T2AM). This PIL material provided specific enrichment superiority for three T2s. After enrichment, the signal intensity of 3,5-T2, 3',5'-T2, and 3,5-T2AM increased 14, 132 and 1.6 folds, respectively, with LOQ of 76, 87, and 107 fM, respectively. Finally, we successfully applied PIL material coupled with HPLC-ESI-MS/MS in enrichment and quantitative determination of free 3,5-T2, 3',5'-T2, and 3,5-T2AM in human serum of 45 thyroid cancer patients and 15 healthy people. We also used free thyroid hormone (FT4) as the calibration reference to eliminate individual differences. We found that the levels of 3,5-T2 (P < 0.001), and 3',5'-T2 (P = 0.001) in patients with thyroid cancer were significantly higher than those in healthy people. Additionally, we further investigated the power of different T2 thyroid hormones divided FT4 to classify thyroid cancer patients and healthy people. And 3,5-T2/FT4 had the highest classification performance for discriminating thyroid cancer patients from healthy people at certain threshold, indicating that 3,5-T2/FT4 in human serum can act as potential biomarkers for "non-invasive" clinical diagnosis of thyroid cancer.

Stir bar sorptive extraction and its application

Recent progress of stir bar sorptive extraction (SBSE) in the past six years is reviewed. The preparation methods including electrodeposition, self-assembly, solvent exchange, physical magnetic adsorption and electrostatic spinning, for the coated stir bar are summarized and compared, specifically for a specific material for coatings fabrication, e.g., carbon-based materials and metal organic frameworks. The emerging materials (e.g., graphene, graphene oxide, carbon nanotubes, monolith, metal-organic frameworks and porous organic polymers) applied for coated stir bar fabrication are one of the focus of this review, along with their respective advantages in extraction process and application in trace analysis. The development and application of extraction apparatus of SBSE are also involved. Based on these information, the development status and prospects of SBSE as an efficient sample pretreatment technique in real sample analysis are discussed.

A banana peel/silicon glue coated stir bar for extraction of aspirin, diclofenac, ibuprofen and mefenamic acid followed by high performance liquid chromatography-UV detection

In the current study, a green, cost-effective, and bio-degradable additive was used for the preparation of a highly efficient sorbent based on silicon glue. Here, a banana peel was pretreated and mixed with silicon glue. It was proved that the prepared banana peel-silicon glue bar is a reliable sorbent for stir bar sorptive extraction of nonsteroidal anti-inflammatory drugs (NSAIDs) including aspirin, diclofenac, ibuprofen and mefenamic acid in human urine and plasma. Compared to the lab-made sorbents, the prepared sorbent showed high extraction performance, high stability, and satisfactory reproducibility and involved easy preparation. In order to optimize the effective factors, different parameters such as (stirring rate, pH, extraction time, desorption time and elution solvent volume) were optimized using response surface methodology (RSM) through applying Central-Composite Design (CCD). Under the optimum conditions, the linear dynamic ranges of the target analytes were investigated in the range of 0.2-200 μg L^-1 with r² higher than 0.9929. Limits of detection (LODs) and limits of quantification (LOQs) of analytes were in the ranges of 0.04-0.5 and 0.15-1.65, respectively. The reproducibility of the method was also investigated by calculating the relative standard deviation. The RSD was measured to be lower than 4.9%. Bar-to-bar reproducibility at a 100 μg L^-1 concentration level was also evaluated to be lower than 5.3% (n = 3). Also, each prepared film can be used up to 64 times without any reduction in extraction performance. Finally, the method was successfully applied for the determination of selected drugs in different biological fluids including urine and plasma samples. The calculated relative recovery in real sample analysis was higher than 90%.