Preparation of nickel-titanium alloy fiber/organosilicone-polyurethane solid phase microextraction head and its application to the determination of seven substituted benzenes in water

Abstract

Toluene-2,4-diisocyanate, polyester polyol, and hydroxy silicone oil were used as raw materials; stannous octoate was used as the catalyst; and cyclohexanone was used as the solvent to synthesize organosilicone-polyurethane (SP). The polymer was coated on the surface of a nickel-titanium alloy fiber treated hydrothermally with potassium hydroxide. It was the prepared for headspace solid phase microextraction (HS-SPME). The polymer structure was analyzed by infrared spectroscopy, the highest temperature of the coating was determined by thermogravimetric analysis, and the surface morphology of the extraction head was observed by scanning electron microscopy. The benzene series of toluene, xylene, m-dichlorobenzene, o-dichlorobenzene, ethyl benzoate, nitrobenzene and benzyl alcohol in water were determined by HS-SPME-gas chromatography (GC) method. There was a good linear relationship between the chromatographic peak area and mass concentration of each measured object. The correlation coefficients (R2) were 0.9926-0.9998. The limits of detection were 0.08-0.24 μg/L. The recoveries of the spiked samples were 95.9%-105.4%, and the relative standard deviations were 1.4%-5.0%. The coating of SPME head adhered more firmly, and had a better adsorption performance for the substituted benzenes in water.