A hollow microporous organic network as a fiber coating for solid-phase microextraction of short-chain chlorinated...

A solid-phase microextraction (SPME) fiber coated with a hollow microporous organic network (H-MON) was fabricated for the analysis of short-chain chlorinated paraffins (SCCPs). The sorbent was prepared by reacting tetra(4-ethynylphenyl)methane and 1,4-diiodobenzene using bis-(triphenylphosphine) palladium(II) as the catalyst in the presence of silica sphere templates, which then were removed by hydrofluoric acid. The SCCPs were quantified by GC-MS working in the negative chemical ionization mode. The H-MON has a high specific surface (701 m²·g^-1) and microporosity (pore size <2 nm). Extraction temperature, extraction time, and ionic strength of the sample solutions were optimized by using the Box-Behnken design. The head-space SPME exhibits better extraction performance than the direct immersion mode. Under optimal working conditions, the detection limit (3 times of the standard deviation) is 0.03 ng·mL^-1 in the water samples. Response is linear in the 0.05-10 ng·mL^-1 concentration range. Repeatability and reproducibility, expressed as the relative standard deviations, ranged from 4.6 to 11.0%. The method was successfully applied in the analysis of SCCPs in water, sediments, organisms, and atmospheric particulate matter samples. Graphical abstract Schematic of the fabrication of a hollow microporous organic network (H-MON) on stainless steel fibers for use in SPME. The method was applied to the determination of short-chain chlorinated paraffins in biological, environmental water and atmospheric particulate matter (PM2.5) samples.