采用纳米碳纤维(CNF)作为固相涂层制备了固相微萃取探头(SPME)并进行了评价。该涂层对苯系物(BTX)富集能力强,最高使用温度可达260℃,250℃解析条件下使用50次以上涂层无脱落现象。与活性碳涂层相比,尽管萃取量略小,但其解析时间仅为活性炭的60%,具有更高的精密度和准确度。对BTX固相微萃取-气相色谱分析结果表明,样品质量浓度在0.1-38.7μg/L范围内与色谱峰面积呈良好线性关系(r=0.9891~0.9940),相对标准偏差为3.9%-5.3%,方法的检出限为2.5×10^-3μg/L。
A new solid-phase microextraction (SPME) probe coated with carbon nanofiber was prepared and applied to the analysis of benzene, toluene and dimethylbenzene (BTX) in gas. The results showed that the coating fiber has high concentration ability and high thermal stability of up to 260℃, and it can be used for over 50 times at 250 ℃. SPME/GC measurements showed that the time required to attain to equilibrium of desorption for carbon nanofiber coated extractor was about 60% or less than that required in case of active carbon coating, and the carbon nanofiber coated extractor showed higher precision and accuracy than the active carbon coating extractor. The good linear relationship between the contents of the standard samples in the range of 0.1 - 38.7μg/L and their areas was obtained, and the correlation coefficients(r) were in the range of 0.9891 - 0.9940. The detection limits were 2.5 ng/L for BTX, with relative standard deviations (RSD) ranging from 3.9% to 5.3 %.