The coating sorbent material determines the sensitivity and selectivity of solid-phase microextraction (SPME). Metal organic frameworks (MOFs) are an emerging class of organic-inorganic hybrid super-molecular materials which are know to have remarkable properties, such as good thermal and chemical stability, superior mechanical properties, and good extraction ability. In this study we adhered porous metal azolate framework ([Zn[(eim)2] (MAF-5, Heim = 2-ethylimidazole acid) onto a stainless steel wire to obtain a novel SPME coating based on a simple and low-cost silicon sealant method. The new fiber possessed a homogeneous, porous surface and showed excellent thermal and solvent stability. Under the optimized conditions, its extraction efficiencies for seven organochlorine pesticides (OCPs) were higher than the commercial fiber (PA 75 �m). Using the self-made silicon sealant@MAF-5 SPME fiber, the limits of detection for seven OCPs were found to range from 0.19 ng/L (o,p-DDT) to 18.3 ng/L (heptachlor). The reproducibility for each single fiber was evaluated and the relative standard deviations (RSDs) ranged from 0.7% to 5.7%. The reproducibility of fiber-to-fiber was 5.5�13.0%. The developed method was successfully applied to the determination of OCPs in the Pearl River water in Guangzhou, China. Hexachlorobenzene (10.8 ng/L), heptachlor (9.1 ng/L), trans-chlordance (5.4 ng/L), endrin (62.5 ng/L), o,p-DDT (19.7 ng/L) and p,p-DDT (11.1 ng/L) were detected. The relative recoveries ranged from 89.4% to 108.6%.

Novel solid phase microextraction (SPME) fiber based on MAF-5 for the determination of organochlorine pesticides in aqueous samples

248th National Meeting (2014)

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