Use of the Synthesized Titania Monolith to Determine Benzoic Acid and Vanillin in Foodstuffs by HPLC

Conductive phthalocyanine-based porous organic polymer as sensing platform for rapid determination of vanillin

Vanillin (Van) is widely utilized in processed foods and medicines for its appealing scent and multiple therapeutic benefits. However, its overconsumption poses a risk to public health, making its quantification essential for ensuring food and medicine safety and quality. This study introduces a stable and conductive phthalocyanine-based porous organic polymer (NiPc-CC POP), synthesized through a straightforward electrophilic substitution of nickel tetra-amine phthalocyanine (NiTAPc) with cyanuric chloride (CC). Appropriate characterization techniques were employed to determine the morphologies and structures of the synthesized materials. Furthermore, the NiPc-CC POP was applied to devise a sensitive Van detection method. Leveraging the high electrocatalytic activity of NiPc-CC POP toward Van oxidation, a linear response of 0.15-32 μmol L-1 was achieved, along with an exceptional detection limit of 0.10 μmol L-1. The sensor demonstrated high selectivity and stability. Samples of human serum and tablets spiked with Van were analyzed, yielding satisfactory recoveries. Consequently, this work contributes to the advancement of sensitive detection platforms for Van at minimal concentrations.

Nano solid phase micro membrane tip and electrochemical methods for vanillin analysis in chocolate samples

A polymer-based nanosensor and electrochemical methods were developed for the quantitative analysis of vanillin. The sample preparation was done using nano solid phase micro membrane tip extraction (NSPMMTE). A novel poly(phenylalanine)/TiO2/CPE sensor was built as the working electrode for the first time for the analysis of the vanillin substance. The electrochemical behavior and analytical performance of vanillin were examined in detail by cyclic voltammetry (CV) and differential pulse stripping voltammetry (DPSV) techniques via the oxidation process. The optimized modules of the DPSV technique that affected the vanillin peak current and peak potential were pH, pulse amplitude, step potential, and deposition time. The electroactive surface areas of bare CPE, TiO2/CPE, and poly(phenylalanine)/TiO2/CPE electrodes were found to be 0.135 cm2, 0.155 cm2, and 0.221 cm2, respectively. The limit of detection (LOD) was 32.6 μg/L in the 0.25-15.0 mg/L working range at pH 7.0. The selectivity of the proposed DPSV method for the determination of vanillin on the modified electrode was investigated in the presence of various organic and inorganic substances, and the determination of vanillin with high recovery was achieved with less than 5% relative error. The analytical application was applied in chocolate samples and the DPSV method was found highly efficient, reproducible, and selective.