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Background Spherical carbons have a porous structure and large surface area for adsorption of macromolecules in water-based adhesives. Supercritical fluid chromatography (SFC) can improve selectivity and obtain better separation for phthalate esters (PAEs). Objective The aim of this study was to develop a simple and green method for the simultaneous determination of 10 PAEs in water-based adhesives using SFC–tandem mass spectrometry with dispersion solid-phase extraction by spherical carbons. Method Separation of PAEs on a Viridis HSS C18 SB column and the parameters affecting the extraction were evaluated. Results Good accuracy and precision were obtained with the recoveries at 0.5, 2.0, and 10.0 mg/kg ranging from 82.9 to 99.5% and the intra- and inter-day precision less than 7%. The method had excellent sensitivity with limits of detection in the range of 0.015–0.029 mg/kg. In the 10–500 ng/mL concentration range, the linear correlation coefficients of all compounds were between 0.9975 and 0.9995. Conclusions The method was applied to the determination of 10 PAEs in actual samples. This method is simple and rapid with low solvent consumption and high extraction efficiency. When applied to the determination of PAEs in actual samples, the method is sensitive and accurate and can meet the batch processing requirements for trace PAEs in water-based adhesives. Highlights PAEs in water-based adhesives can be determined using inexpensive materials and simple procedures with SFC.

In this study, cetyltrimethylammonium bromide and zeolitic imidazolate framework-8 (ZIF-8) were first assembled via the chemical co-precipitation, and high-quality carbon-based metal-free nanomaterials were synthesized using a heat-treatment process. The internal and morphological characteristics of hexagonal Star ZIF-8 were investigated using scanning electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. The electrochemical sensor with a good response to Cd(II) was prepared via square-wave anodic stripping voltammetry (SWASV) with Star ZIF-8 nanomaterial-modified glassy carbon electrodes. The main parameters were adjusted to obtain the optimal stripping response and a wide linear range. Concurrently, under the calculation of SWASV, the sensitivity of Star ZIF-8-Nafion/GCE to Cd(II) was increased by five orders of magnitude (0.5-230 μg/L), and the determination level was even low to 0.48 μg/L. Based on the high anti-interference ability and stability of the sensor, the application potential of Star ZIF-8 carbon-based metal-free nanomaterials for the detection of trace Cd(II) in was confirmed.

In this study, a molecularly imprinted electrochemical sensor based on graphene/Au nanoparticles (G@AuNPs) compound materials and molecularly imprinted membrane (MIM) modified glassy carbon electrodes (GCEs) was developed for the sensitive detection of colchicine in pharmaceuticals and serum (MIM/G@AuNPs/GCE). The film was formed by the in situ polymerization of colchicine-imprinted membranes on the G@AuNPs-modified GCE using methacrylic acid as the functional monomer. The specific surface area, catalytic performance, and electrical conductivity of the electrode increased on account of the formation of G@AuNPs compound materials, thereby improving the sensitivity of the sensor. The MIM as a preconcentrator exhibited chemical selectivity. Under optimal conditions, the MIM/G@AuNPs/GCE sensor exhibited high selectivity and high anti-interference ability. Moreover, good linearity was obtained in the range of 1.2 × 10−8 to 1.2 × 10−6 mol L−1 and 1.2 × 10−6 to 1.0 × 10−4 mol L−1 of colchicine with a detection limit of 4.8 × 10−9 mol L−1. The sensor was successfully applied for the direct determination of colchicine in colchicine tablets and human serum samples, with a relative standard deviation of less than 3.1% (n = 5) and recoveries ranging from 97.5% to 110.0%.

To develop a convenient method for sensitive and selective determination of platinum in complicated matrices, an ion-imprinted electrode was studied by in situ polymerization of Pt(IV) ion-imprinted membranes (Pt(IV)-IIMs) on the surface of a glassy carbon electrode (GCE). After the experimental parameters for the preparation of Pt(IV)-IIMs such as functional monomer, molar ratio of template, monomer and cross-linking agent together with extraction condition were optimized, an electrode with good regeneration, high stability and specific recognition to Pt(IV) was obtained by modifying GCE with Pt(IV)-IIMs prepared in acetonitrile using allylurea (NAU) as functional monomer, ethylene glycol dimethacrylate (EGDMA) as cross-linking agent, azobisisobutyronitrile (AIBN) as initiator under the molar ratio of template (H2PtCl6), NAU and EGDMA as 1 : 4 : 40. The resulting electrode named as Pt(IV)-IIMs/GCE exhibits high response sensitivity to Pt(IV) in phosphate buffer (pH 5.29). The calibration graph for the determination of Pt(IV) by Pt(IV)-IIMs/GCE is linear in the range of 2.0 × 10−8 ∼ 2.5 × 10−4 mol L−1 with a detection limit of 4.0 × 10−9 mol L−1. No metal ions tested at a concentration 25 times higher than that of Pt(IV) interfered in the determination. The electrode was successfully applied to determine platinum in catalyst and plant samples with a relative standard deviation (RSD) of less than 3.0% (n = 5) and recoveries in the range of 97.8–103.6%.