GBT 30053-2013 粗苯中三苯含量的测定方法(气相色谱法)
【前言介绍】
粗苯含有多种有机化工原料，经加氢处理后可作为动力苯，也可蒸馏分离出苯、甲苯、二甲苯等重要的基本有机化工原料。近几年，出口粗苯的数量逐年增多。对其主要成份苯、甲苯、二甲苯含量的测定成为商品的主要检验内容。
【测定原理】粗苯样品被载气（N2）带入色谱柱，用交联键合聚乙二醇（PEG-20M）石英弹性毛细管色谱柱对组分进行分离，氢火焰离子化检测器（FID）分析苯、甲苯、二甲苯（对二甲苯、间二甲苯、邻二甲苯）的含量。用色谱工作站将样品组分与标准样品中各组分的色谱峰对比，根据爆料时间对各组分定性，按面积归一法对各组分定量。
【仪器配置】
产品名称          型号     规格及说明
气相色谱仪       GC2020  FID检测器、分流进样口共同组成
色谱工作站       N2000    双通道（电脑、打印机自配）
色谱柱           毛细管柱  30m*0.25mm
高纯氢气发生器   HK-300  氢气流量300ml/min
高纯氧气钢瓶     40L    氧气流量300ml/min
高纯氮气钢瓶     40L    氮气流量300ml/min
标准样品         苯、甲苯、邻二甲苯 对二甲苯 间二甲苯: 分析纯; 
微量注射器       10uL
【色谱条件】
进样口温度180℃ 
载气流速( N2) 60mL/min 
柱箱温度70℃
FID 温度250℃ 
氢气流速75mL/min
空气流速100mL/min 

峰号     峰名           保留时间     峰高           峰面积          含量        

1                        2.932       225.750        481.300         0.0105      

2                        3.082       1141.826       2413.950        0.0529      

3                        3.265       895.769        1553.962        0.0340      

4                        3.340       253.385        544.938         0.0119      

5                        3.490       538.615        1442.900        0.0316      

6                        3.590       172.769        397.038         0.0087      

7                        3.682       6885.539       10886.450       0.2384      

8                        3.840       347.500        820.100         0.0180      

9                        3.940       635.583        1553.179        0.0340      

10                       4.107       194.917        592.821         0.0130      

11                       4.282       510.222        942.500         0.0206      

12                       4.498       43.857         162.700         0.0036      

13       甲基环戊烷      4.698       566.219        1239.845        0.0272      

14                       4.807       34.875         83.755          0.0018      

15       苯              5.240       580758.250     3441723.000     75.3671     

16       环己烷          5.340       1895.889       3247.650        0.0711      

17                       5.640       53.913         254.150         0.0056      

18                       5.798       30.000         65.500          0.0014      

19                       5.873       46.000         97.300          0.0021      

20                       6.165       249.846        654.400         0.0143      

21       甲基环己烷      6.815       562.483        1486.300        0.0325      

22                       6.982       864.500        6646.100        0.1455      

23       甲苯            7.948       92803.813      544485.250      11.9232     

24                       8.132       497.481        1494.365        0.0327      

25                       8.540       72.857         187.200         0.0041      

26                       8.807       41.000         76.700          0.0017      

27                       9.240       170.105        582.850         0.0128      

28                       9.465       164.032        1556.300        0.0341      

29                      10.365       52.333         111.300         0.0024      

30                      10.540       443.813        1214.400        0.0266      

31       乙苯           10.940       1068.243       3120.900        0.0683      

32       间对二甲苯     11.282       22045.750      106737.953      2.3374      

33                      11.423       124.500        674.650         0.0148      

34       苯乙烯         11.848       16835.666      54033.617       1.1832      

35       邻二甲苯       11.998       6993.667       19280.033       0.4222      

36                      12.223       102.851        528.450         0.0116      

37                      12.582       103.133        279.100         0.0061      

38                      13.623       48.857         236.700         0.0052      

39                      14.148       1106.667       3832.778        0.0839      

40                      14.398       2388.000       7482.522        0.1639      

41                      14.598       68.348         174.883         0.0038      

42                      14.682       275.261        756.817         0.0166      

43                      15.032       3108.417       13452.523       0.2946      

44                      15.148       2658.500       9226.377        0.2020      

45                      15.582       75.737         223.850         0.0049     

【操作方法】
在上述条件下，通用微量注射器每次分别吸取苯、甲苯各1.0uL，进行气相色谱分析，记录色谱图，准确测量各组分的保留时间（tr）及峰高或峰面积。
3.样品的保留值及含量的测定
取混合样品1.0uL，在与纯试剂相同的条件下进行色谱分析，准确测量各组分的保留值及峰高或峰面积，开展定性定量分析，求出各组分的百分含量
【注意事项】
1.注射器使用前应先用丙酮或无水乙醇抽洗6-8次左右，然后再用所要分析的样品抽洗6-8次左右。
2.氢气是一种危险气体，实验过程中一定要按要求规范操作，而且色谱实验室一定要有良好的通风设备。
3.氢焰检测器的温度要大于100℃C，以防止水蒸气在检测器中冷凝