GBT 30053-2013 粗苯中三苯含量的測(cè)定方法(氣相色譜法)
【前言介紹】
粗苯含有多種有機(jī)化工原料，經(jīng)加氫處理后可作為動(dòng)力苯，也可蒸餾分離出苯、甲苯、二甲苯等重要的基本有機(jī)化工原料。近幾年，出口粗苯的數(shù)量逐年增多。對(duì)其主要成份苯、甲苯、二甲苯含量的測(cè)定成為商品的主要檢驗(yàn)內(nèi)容。
【測(cè)定原理】粗苯樣品被載氣（N2）帶入色譜柱，用交聯(lián)鍵合聚乙二醇（PEG-20M）石英彈性毛細(xì)管色譜柱對(duì)組分進(jìn)行分離，氫火焰離子化檢測(cè)器（FID）分析苯、甲苯、二甲苯（對(duì)二甲苯、間二甲苯、鄰二甲苯）的含量。用色譜工作站將樣品組分與標(biāo)準(zhǔn)樣品中各組分的色譜峰對(duì)比，根據(jù)爆料時(shí)間對(duì)各組分定性，按面積歸一法對(duì)各組分定量。
【儀器配置】
產(chǎn)品名稱          型號(hào)     規(guī)格及說(shuō)明
氣相色譜儀       GC2020  FID檢測(cè)器、分流進(jìn)樣口共同組成
色譜工作站       N2000    雙通道（電腦、打印機(jī)自配）
色譜柱           毛細(xì)管柱  30m*0.25mm
高純氫氣發(fā)生器   HK-300  氫氣流量300ml/min
高純氧氣鋼瓶     40L    氧氣流量300ml/min
高純氮?dú)怃撈?    40L    氮?dú)饬髁?00ml/min
標(biāo)準(zhǔn)樣品         苯、甲苯、鄰二甲苯 對(duì)二甲苯 間二甲苯: 分析純; 
微量注射器       10uL
【色譜條件】
進(jìn)樣口溫度180℃ 
載氣流速( N2) 60mL/min 
柱箱溫度70℃
FID 溫度250℃ 
氫氣流速75mL/min
空氣流速100mL/min 

峰號(hào)     峰名           保留時(shí)間     峰高           峰面積          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       甲基環(huán)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       環(huán)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       甲基環(huán)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       間對(duì)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       鄰二甲苯       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】
在上述條件下，通用微量注射器每次分別吸取苯、甲苯各1.0uL，進(jìn)行氣相色譜分析，記錄色譜圖，準(zhǔn)確測(cè)量各組分的保留時(shí)間（tr）及峰高或峰面積。
3.樣品的保留值及含量的測(cè)定
取混合樣品1.0uL，在與純?cè)噭┫嗤臈l件下進(jìn)行色譜分析，準(zhǔn)確測(cè)量各組分的保留值及峰高或峰面積，開(kāi)展定性定量分析，求出各組分的百分含量
【注意事項(xiàng)】
1.注射器使用前應(yīng)先用丙酮或無(wú)水乙醇抽洗6-8次左右，然后再用所要分析的樣品抽洗6-8次左右。
2.氫氣是一種危險(xiǎn)氣體，實(shí)驗(yàn)過(guò)程中一定要按要求規(guī)范操作，而且色譜實(shí)驗(yàn)室一定要有良好的通風(fēng)設(shè)備。
3.氫焰檢測(cè)器的溫度要大于100℃C，以防止水蒸氣在檢測(cè)器中冷凝