Rapid detection of sulfamethoxazole in plasma and food samples with in-syringe membrane SPE coupled with solid-phase fluorescence spectrometry

One-pot derivatization/magnetic solid-phase extraction coupled with liquid chromatography-fluorescence detection for the rapid determination of sulfonamide residues in honey

Consuming foods with excess sulfonamide residues threatens human health, underscoring the importance of their detection in food. This study presents an innovative one-pot derivatization/magnetic solid-phase extraction (OPD/MSPE) method for sulfonamides analysis. This approach integrates the derivatization and extraction steps into a single process. The sample solution, along with the derivatization reagent fluorescamine and the sorbent magnetic hydroxyl multi-walled carbon nanotubes, is mixed and vortexed for 3 min. This procedure simultaneously conducts derivatization and extraction, with easy phase separation using an external magnet. This streamlined sample preparation method is completed in only 5 min and, when combined with liquid chromatography-fluorescence detection (LC-FLD), demonstrates excellent linearity (R2 > 0.99) and satisfactory detection limits (0.004-0.04 ng/g) for the quantification of nine sulfonamides in honey samples. The proposed OPD/MSPE-LC-FLD method is distinguished by its simplicity, rapidity, high sensitivity, and specificity, making it an outstanding advancement in the field of food safety analysis.

Fluoranthene determination based on a rapid and sensitive syringe extraction and solid-phase fluorescence technique

A rapid and sensitive strategy was proposed for the detection of fluoranthene (FL), which is a polycyclic aromatic hydrocarbon (PAH), in water samples. In this work, syringe solid-phase extraction (SPE) combined with solid-phase fluorescence spectrometry was used to determine FL in PAHs polluted environmental samples. The fluorescence signals were directly monitored on the membrane surface after FL was enriched by syringe SPE. Under the optimal conditions, the proposed method showed a linear relationship in the concentration range 2-50 μg/L with a correlation coefficient (R2 ) of 0.998, and the limit of detection was 0.143 μg/L. The recoveries varied from 93.47% to 109.81% in the actual samples, with the relative standard deviations (n = 3) ranging from 2.06% to 6.32%. According to the results, the established method can be applied in the field of rapid detection as it is fast, simple, portable, and highly sensitive, and has strong anti-interference.

Biochar/sodium alginate mixed matrix membrane as adsorbent for in-syringe solid-phase extraction towards trace nitroimidazoles in water samples prior to ultra-high-performance liquid chromatography-tandem mass spectrometry analysis

In the present work, the herb (Poria cocos (Schw.) Wolf) residue, as an environmentally friendly and renewable biomass source, was converted into novel biochar. Biochar/sodium alginate mixed matrix membrane was fabricated. On this basis, a biochar/sodium alginate mixed matrix membrane-based in-syringe solid-phase extraction was developed combined with ultra-high performance liquid chromatography-tandem mass spectrometry to determine nitroimidazoles in water samples. The factors including times of exaction, type, and volume of elution solvent, and sample solution pH were thoroughly optimized. Then the correlation coefficient was 0.9995-0.9997. The limit of detection of four analytes was between 0.006 and 0.014 ng/mL, and the recovery was between 79.02% and 99.1%. Consequently, the established method would provide a new perspective on monitoring nitroimidazoles in water samples.

In-syringe solid phase extraction and in-syringe vortex-assisted solidified floating organic drop microextraction of Sb(III) and Sb(V) in rice wines with determination by graphite furnace atomic absorption spectrometry

The current non-chromatographic speciation methods generally involve the conversion of different species by oxidation/reduction reactions, which may cause inherent problems such as contamination risk, time consumption and complex operations. In this work, in-syringe solid phase extraction (IS-SPE) was combined with in-syringe vortex-assisted solidified floating organic drop microextraction (IS-VA-SFODME) for the detection of Sb(V) and Sb(III) in rice wines by graphite furnace atomic absorption spectrometry. Firstly, IS-SPE involved the use of ZnFe₂O₄ nanotubes as the sorbent for the isolation and enrichment of Sb(V) and removal of the matrix components such as ethanol, pigment, sugars and carbohydrates. Then, IS-VA-SFODME was used for enriching Sb(III) in the original sample solution after IS-SPE. This technique exhibited good anti-interference ability and high enrichment efficiency without tedious pre-oxidation/pre-reduction and centrifugation/filtration operations, which may cause the contamination of samples. Under the selected conditions, the detection limits were 4.5 ng L^-1 and 3.2 ng L^-1 for Sb(III) and Sb(V) with relative standard deviations of 7.3% and 5.1%, respectively. This procedure was used with satisfactory results for the detection of Sb(III) and Sb(V) in rice wine samples and a certified reference material of water sample. Recoveries of spiked experiments ranged from 91.0 to 107%.

Rapid determination of trace Cu2+ by an in-syringe membrane SPE and membrane solid-phase spectral technique

A new in-syringe membrane SPE and solid-phase visible spectral method was proposed for the rapid extraction and visible spectral determination of trace Cu²⁺. The chelation and membrane SPE can be accomplished in a syringe. The yellow Cu(DDTC)₂ complex was separated using a polyethersulfone membrane from the sample solution. Then, the complex can be detected directly on the polyethersulfone membrane utilizing solid-phase visible absorbance spectra without elution. The proposed method simplified the experimental procedure and improved the sensitivity to the μg L^-1 level. Furthermore, this method is environmentally friendly since it avoids the use of organic solvents. After the investigation of the influence of different variables on the membrane SPE procedure, water and blood plasma were analyzed to validate the proposed method. A LOD of 0.04 μg L^-1 and recoveries of 96.0-103.7% confirmed that the present work can be applied for the determination of trace Cu²⁺ in water and blood plasma samples.