Shang Chuang1, Yang Gengliang1, 2 , Wei Chunliang1, Li
Li1 Abstract Objective To develop a capillary gas chromatography method for the determination of nitrobenzene in milk slice. Method Nitrobenzene was extracted by benzene. The analysis was performed on a SE-54 capillary column. The detector is FID. The temperature was elevated from 70-120º C,10.00ºC·min-1,120ºC maintains 3min, 120℃-220ºC, 20.00ºC·min-1,220ºC maintains 3min. The carrier gas was N2. The flow rate was 2.0 mL·min-1. Result Nitrobenzene was linear within the range from 0.2976 to 0.7737mg·mL-1. The standard regression equation: Y = 30395x - 303.1, r=0.9994. The average recovery was 99.3%. Conclusion This method has high sensitivity, good reproducibility and convenient for operation. The result is reliable and it provides nitrobenzene was accurate detected qualitatively and quantitatively by this method.Keywords Gas chromatography; Nitrobenzene; Benzene 奶片中硝基苯残留的气相色谱检测 商闯1, 杨更亮1,2,魏春亮1,李莉1 摘要 目的 建立一种方便、快速、灵敏的毛细管气相色谱检测奶片中硝基苯的方法。方法
用苯做萃取剂提取硝基苯;采用毛细管色谱柱SE-54;FID检测器;程序升温:70-120℃,10.00℃·min-1,120℃保持3min,120℃-220℃,20.00℃·min-1,220℃保持3min;载气:氮气;流速:2.0mL·min-1。结果
硝基苯的线性范围02976~0.77370μg·mL-1;标准回归方程:Y
= 30395x - 303.1,r=0.9994,平均加样回收率99.3%。结论 该方法灵敏度高,重现性好,操作方便,结果可靠,能够准确地对奶片中的硝基苯进行定性和定量检测。
1 材料与方法 1.5 样品的处理 将50g奶片溶于在100 mL超静水中,取溶液5 mL于25 mL容量瓶中,加入0.1mol·L-1盐酸5 mL,115℃高压灭菌20 min。冷却后用醋酸钠溶液调至pH 4.5,加入淀粉酶和蛋白酶各0.1 g,37℃酶解2 h.,然后定容至25ml,过滤后取滤液5 mL于10 mL离心管中,加入2.5 mL色谱纯苯,超声震荡后于40℃水浴锅中静置分层。吸取上层清液1.5 mL于试管中,用0.5 g无水碳酸钠除水,4000 r·min-1离心5 min,取上清液1 mL于2 mL EP管中,用色谱纯苯定容到2 mL,用于气相色谱检测。 1.6 回收率与精密度的测定 分取5ml奶片溶液5份,分别加入10mL、20mL、40mL和80mL硝基苯储备液,得到浓度分别为0.1240mg·mL-1、0.2480mg·mL-1、0.4960mg·mL-1和0.9920 mg·mL-1奶样,按照奶样处理方法处理后用气相色谱检测,计算回收率。 1.7 最低检测限与最低定量限的确定 以信噪比3(S/N=3)测量最低检测限,以信噪比6(S/N=6)测量最低定量限。 1.8 气相色谱条件 色谱柱:SE-54;长度:50.0m;膜厚:0.33um;直径:320um;进样口温: 200℃;检测器温度: 300℃;初始温度: 70 ℃; 初始时间:2.00 min;平衡时间:1.00 min;程序升温:70-120℃,10.00℃·min-1,120℃保持3min;120℃-220℃,20.00℃·min-1,220℃保持3min;载气:氮气;流速:2.0mL·min-1。 2 结果与讨论 1:苯 2:硝基苯 Fig.1 Chromatogram of nitrobenzene and benzene 1: benzene 2: nitrobenzene 2.2 线性范围和检出限
图2 苯中标准品的标准曲线 Fig.2 Standard curve of standard preparation in benzene 2.3 回收率 Table 1 Results of recovery
由表1可以得到,该方法样品回收率均大于98.5%以上,具有高准确度。 2.4 最低检出限 3 结论 REFERENCES
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