Metal/heteroatom-doped carbon-based hybrid material as the matrix for rapid and high-throughput identification of phthalate esters in complex samples by laser desorption/ionization.

A novel matrix of metal particles and metal oxides modified N-doped multi-walled carbon nanotubes (N-MWCNTs/AuNPs/CoO) is introduced for the rapid detection of phthalate esters (PAEs) using surface-assisted laser desorption/ionization mass spectrometry (SALDI-MS). By leveraging the synergistic effects of metal/heteroatom-doped carbon-based components, this innovative hybrid material demonstrated exceptional ionization efficiency for PAEs. Specifically, it enables the detection of bis(2-ethylhexyl) phthalate (DEHP) at concentrations as low as of 1 µg·mL⁻. Moreover, the N-MWCNTs/AuNPs/CoO composite not only surpassed conventional organic matrices in terms of ionization efficiency and reproducibility, but also facilitated the effective enrichment of PAEs, achieving an enrichment efficiency range from 94.1% ± 5.8% to 98.2% ± 2.3%. Furthermore, this method was successfully applied to detect DEHP in human serum and urine samples, with urinary DEHP concentrations estimated ranging from 29.2 to 38.4 ng·mL⁻. This approach represents a promising strategy for high-throughput PAE detection, offering significant potential for applications in environmental and biomedical analysis.