Application of cobalt-cerium-iron ternary layered double hydroxide for extraction of perfluorooctane sulfonate followed by HPLC-MS/MS analysis.

Herein, Ce-doped CoFe layered double hydroxide (LDH), noted as CoCeFe ternary LDH, was prepared using the co-precipitation route. Prosperous synthesis of CoFe LDH and successful partial replacement of iron cations with cerium cations in CoCeFe ternary LDH were confirmed by X-ray diffraction patterns, energy-dispersive X-ray spectroscopy, and elemental dot-mapping images. Nanosheet morphology was recognized for both CoFe LDH and CoCeFe ternary LDH from scanning electron microscopy and transmission electron microscopy micrographs. In the following, a dispersive solid phase extraction (DSPE) method was developed using the synthesized CoCeFe ternary LDH as a sorbent for extracting perfluorooctanesulfonic acid (PFOS) from wastewater samples. For the selective analysis of PFOS, high-performance liquid chromatography-tandem mass spectroscopy (HPLC-MS/MS) in multiple reaction monitoring mode was used. Analytical parameters such as the limit of detection equal to 0.02 µg/L, with a linear range of 0.05-300 µg/L, the limit of quantification equal to 0.05 µg/L, and an enrichment factor equal to 23.3 were achieved for PFOS at the optimized condition (sorbent: 5 mg of CoCeFe ternary LDH, eluent type and volume: 150 µL mobile phase, pH: 3, adsorption time: 3 min, and desorption time: 5 min). The developed strategy for the analysis of PFOS was tested in real wastewater samples, including copper mine and petrochemical wastewater. The amount of analytes in real samples was calculated using the standard addition method, and good relative recovery in the range of 86%-105% was obtained. The main novelty of this research is the application of CoCeFe ternary LDH to extract the PFOS from wastewater using the DSPE method for determination by HPLC-MS/MS.

Electrochemical-Based Sensing Platforms for Detection of Glucose and H2O2 by Porous Metal-Organic Frameworks: A Review of Status and Prospects.

Establishing enzyme-free sensing assays with great selectivity and sensitivity for glucose and H2O2 detection has been highly required in biological science. In particular, the exploitation of nanomaterials by using noble metals of high conductivity and surface area has been widely investigated to act as selective catalytic agents for molecular recognition in sensing platforms. Several approaches for a straightforward, speedy, selective, and sensitive recognition of glucose and H2O2 were requested. This paper reviews the current progress in electrochemical detection using metal-organic frameworks (MOFs) for H2O2 and glucose recognition. We have reviewed the latest electrochemical sensing assays for in-place detection with priorities including straightforward procedure and manipulation, high sensitivity, varied linear range, and economic prospects. The mentioned sensing assays apply electrochemical systems through a rapid detection time that enables real-time recognition. In profitable fields, the obstacles that have been associated with sample preparation and tool expense can be solved by applying these sensing means. Some parameters, including the impedance, intensity, and potential difference measurement methods have permitted low limit of detections (LODs) and noticeable durations in agricultural, water, and foodstuff samples with high levels of glucose and H2O2.