论文部分内容阅读
目的建立适合于检测酸奶中微量苯及其同系物的顶空固相微萃取-气质联用检测方法。方法采用顶空固相微萃取进行目标物分离富集,用萃取头进行固相微萃取后上机测定,顶空固相微萃取条件为样品装液量10 mL,NaCl添加量2.0 g,转子设定转速为5000 r/min,萃取时间20 min,萃取温度60℃。采用相对校正因子内标法对苯系物进行定量分析。结果以氯苯为内标物,苯、甲苯、对(间)二甲苯、邻二甲苯、苯乙酮的相对校正因子依次为:10.87、3.07、0.34、0.55、4.867,检出限依次为:2、0.05、0.01、0.01、0.05μg/L(信噪比S/N≥3),定量限依次为:5、0.12、0.05、0.06、0.15μg/L(信噪比S/N≥10)。苯系物的加标回收率为82%~104%,相对标准偏差(RSD)均小于4%。采用此方法对6种酸奶样品进行检测,苯系物的含量在4~24μg/L范围之间。结论该方法灵敏度高,准确性好,能够很好的检测酸奶中的苯系物含量。
Objective To establish a suitable GC-MS method for the determination of trace benzene and its homologues in yoghurt. Methods The headspace solid-phase microextraction was used to separate and enrich the target. The headspace solid-phase microextraction was performed on the headspace. The headspace solid-phase microextraction conditions were as follows: 10 mL sample volume, 2.0 g NaCl addition, Set the speed of 5000 r / min, extraction time 20 min, extraction temperature 60 ℃. The relative calibration factor internal standard method for quantitative analysis of benzene series. Results The relative correction factors of benzene, toluene, p-xylene, o-xylene and acetophenone were 10.87, 3.07, 0.34, 0.55 and 4.867, respectively. The detection limits were as follows: (S / N≥3). The quantitative limits were as follows: 5,0.12,0.05,0.06,0.15μg / L (signal to noise ratio S / N≥10) . The spiked recoveries of benzene series compounds ranged from 82% to 104% with relative standard deviations (RSDs) less than 4%. Six kinds of yogurt samples were tested by this method. The content of benzene series was between 4 ~ 24μg / L. Conclusion The method has high sensitivity, good accuracy and good detection of benzene compounds in yogurt.