酸奶中苯及苯同系物气相色谱-质谱检测 方法的建立

Detection of benzene and benzologue in yogurt by gas chromatography-mass spectrometry

中文关键词:  酸奶  苯  苯同系物  气相色谱-质谱法

英文关键词:yogurt  benzene  benzologue  gas chromatography-mass spectrometry

中文摘要:

      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、0.05 μg/L(信噪比S/N≥3), 定量限依次为: 5、0.12、0.05、0.06、0.15 μg/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4~24 μg/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。

英文摘要:

      Objective To establish a qualitative and quantitative method for the determination of BTEX (benzene, toluene, xylene, acetophenone) in yogurt by headspace solid-phase microextraction and gas chromatography mass spectrometry technology. Methods The headspace solid-phase microextraction conditions were as follows: sample volume 10 mL, amount of NaCl 2.0 g, extraction time 20 min, and extraction temperature 60 ℃. Relative correction factor was used for the quantitative analysis of BTEX. Results Chlorobenzene was used as the internal standard substance and the relative correction factors of benzene, toluene, p(m)-xylene, o-xylene and acetophenone were 10.87, 3.07, 0.34, 0.55 and 4.867, respectively. The limits of detection (LODs) of benzene, toluene, p(m)-xylene, o-xylene and acetophenone were 2, 0.05, 0.01, 0.01, 0.05 μg/L(S/N≥3), respectively, and the limits of quantification were 5, 0.12, 0.05, 0.06, 0.15 μg/L(S/N≥10), respectively. The recoveries of BTEX were 82%~104% and RSD were less than 4%. The content of BTEX in 6 kinds of yogurt samples was in the range of 4~24 μg/L detected by this method. Conclusion The established method has excellent accuracy and sensitivity, which can be used to detect the trace BTEX in yogurt.