Determination of Acidolysis Hydrocarbons in Oil/Gas Geochemical Exploration Samples by Gas Chromatography
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摘要:
本文通过改进传统制备酸解烃样品的单套脱气装置, 采用多套酸解烃脱气装置, 建立了自动进样-毛细管柱气相色谱法测定油气化探样品中酸解烃的分析方法, 并对主要仪器分析条件及质量监控方法进行了讨论。结果表明, 样品在真空40℃水浴条件下酸解反应10 min, 酸解烃脱出气储存于密封瓶中供气相色谱检测, 方法检出限为0.007~0.057μL/kg, 精密度(RSD, n=12) 为0.8%~1.1%。对105件样品2次独立测试结果的相对偏差为0.01%~19.66%, 平均值为7.81%(以甲烷计算)。该方法能够满足油气化探酸解烃样品分析的质量要求, 并在天然气水合物勘查中取得了较好的应用效果。
Abstract:A method for the determination of acidolysis hydrocarbons in oil/gas geochemical exploration samples by autosampler-GC-FID using multiple acidolysis devices was developed based on the improvement of traditional single set acidolysis equipment. The optimization of the main analytical conditions and quality control are also discussed in detail in this paper. The acidolysis of samples was carried out in vacuum in a 40℃ water bath for 10 min. The emitted gases of acidolysis hydrocarbons were stored in sealed bottles for gas chromatography determination. The detection limit of this developed method was 0.007-0.057μL/kg with relative standard deviation(RSD) of 0.8%-1.1%. The relative deviation(RD) of two independent tests for 105 samples varied from 0.01% to 19.66% with an average of 7.81%(calculated by methane). This proposed method is suitable for the determination of acidolysis hydrocarbons in oil/gas geochemical exploration samples and has been successfully used in natural gas hydrate prospecting.
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表 1 不同称样质量酸解烃分析结果
Table 1. Analytical results on the determination of acidolysis hydrocarbons at different sample weight
样品
编号质量
(g)酸解烃含量(μL/kg) 甲烷相对偏差
(%)CH4 C2H6 C2H4 C3H8 C3H6 iC4H10 nC4H10 iC5H12 nC5H12 ΣC2+ 787 2.0 146.22 6.74 0.10 3.64 0.11 0.32 0.33 0.37 0.17 11.79 7.19 5.0 146.52 9.28 0.16 3.48 0.13 1.12 1.27 0.82 0.23 16.49 7.00 10.0 152.12 9.29 0.19 4.45 0.14 1.33 1.28 0.59 0.20 17.45 3.44 20.0 163.81 9.82 0.08 4.26 0.10 1.21 1.21 0.73 0.24 17.65 3.97 40.0 179.05 10.88 0.08 4.90 0.09 1.29 1.21 0.88 0.62 19.94 13.65 666 2.0 525.97 36.68 0.20 17.06 0.11 5.07 4.52 1.97 1.07 66.66 12.18 5.0 564.78 41.03 0.14 18.75 0.10 5.24 6.20 4.45 2.00 77.91 5.70 10.0 609.31 43.32 0.13 21.17 0.11 6.53 6.14 4.81 1.74 83.95 1.73 20.0 636.13 45.85 0.13 21.64 0.07 6.52 6.55 5.09 1.81 87.65 6.21 40.0 658.47 48.42 0.17 22.77 0.07 6.23 6.49 5.09 1.92 91.14 9.94 727 2.0 1235.61 96.82 0.37 53.15 0.27 17.64 13.36 13.33 3.95 198.87 8.68 5.0 1276.29 102.45 0.30 57.24 0.24 19.83 17.16 14.76 5.62 217.60 5.67 10.0 1386.73 115.07 0.23 65.02 0.17 20.38 18.15 18.69 6.84 244.56 2.49 20.0 1432.70 122.20 0.16 69.06 0.14 21.13 19.28 17.85 6.41 256.22 5.89 40.0 1433.75 125.79 0.16 70.96 0.17 21.46 19.75 18.30 6.55 263.14 5.97 表 2 不同反应温度酸解烃分析结果
Table 2. Analytical results on the determination of acidolysis hydrocarbons at different reaction temperature
样品
编号温度
(℃)酸解烃含量(μL/kg) 甲烷相对偏差
(%)CH4 C2H6 C2H4 C3H8 C3H6 iC4H10 nC4H10 iC5H12 nC5H12 ΣC2+ 819 20 60.55 10.10 0.29 4.26 0.20 0.61 1.41 0.49 0.54 17.92 5.07 30 63.19 10.13 0.27 4.22 0.23 0.63 1.45 0.49 0.53 17.95 0.94 40 63.95 10.27 0.31 4.33 0.24 0.57 1.41 0.45 0.55 18.12 0.25 50 67.46 11.07 0.38 4.69 0.25 0.60 1.59 0.50 0.58 19.67 5.76 35 20 216.51 13.25 0.26 4.84 0.13 1.29 1.27 1.14 0.46 22.65 8.06 30 234.62 13.92 0.28 5.05 0.22 1.19 1.35 3.16 0.38 25.53 0.37 40 240.45 14.22 0.28 5.15 0.21 1.07 1.26 4.42 0.44 27.05 2.10 50 250.42 14.69 0.33 5.30 0.19 1.19 1.35 3.73 0.41 27.18 6.34 33 20 953.57 78.00 0.17 28.54 0.13 8.40 8.25 5.90 3.20 132.594 5.72 30 1020.38 80.51 0.25 29.30 0.19 8.31 8.69 5.30 2.48 135.039 0.89 40 1033.13 81.89 0.28 30.67 0.15 8.44 10.12 6.63 3.40 141.587 2.15 50 1038.51 82.73 0.36 30.88 0.20 9.09 9.91 7.29 3.66 144.129 2.68 表 3 不同反应时间酸解烃分析结果
Table 3. Analytical results on the determination of acidolysis hydrocarbons at different reaction time
样品
编号时间
(min)酸解烃含量(μL/kg) 甲烷相对偏差
(%)CH4 C2H6 C2H4 C3H8 C3H6 iC4H10 nC4H10 iC5H12 nC5H12 ΣC2+ 374 5 959.49 30.70 0.11 11.38 0.14 2.72 3.51 1.76 0.99 51.31 1.12 10 966.95 32.46 0.26 11.26 0.16 3.39 3.61 1.97 1.02 54.14 0.35 15 982.46 32.01 0.53 11.88 0.16 3.39 3.50 1.80 1.06 54.34 1.25 30 972.62 32.02 0.24 12.43 0.14 3.51 3.19 2.02 1.40 54.94 0.23 2 5 2113.93 38.94 0.22 12.97 0.16 2.53 3.67 1.63 1.36 61.48 3.21 10 2209.69 40.72 0.19 12.95 0.20 2.50 3.68 1.73 1.40 63.36 1.17 15 2245.27 41.25 0.24 12.85 0.21 2.54 3.77 1.60 1.40 63.85 2.80 30 2167.66 40.23 0.50 12.26 0.29 2.90 3.76 1.59 1.24 62.76 0.75 11 5 131.18 10.45 0.05 4.80 0.05 1.28 1.18 1.03 0.46 19.30 2.01 10 134.37 10.64 0.07 4.86 0.08 1.28 1.28 0.91 0.40 19.52 0.37 15 135.61 10.89 0.06 5.33 0.08 1.25 1.36 1.14 0.55 20.67 1.30 30 134.34 11.88 0.09 4.93 0.08 1.59 1.67 1.13 0.44 21.81 0.35 表 4 测定酸解烃C1~C5的准确度、精密度和检出限
Table 4. The accuracy, precision and detection limits of the method for acidolysis hydrocarbons C1~C5
组分 浓度
(μL/L)相对误差
(%)RSD
(%)检出限
(μL/kg)CH4 99.52 0.02 0.8 0.057 C2H6 9.87 -1.31 0.9 0.021 C2H4 9.53 -0.74 0.9 0.022 C3H8 10.2 -1.94 1.0 0.017 C3H6 9.83 -1.73 1.0 0.017 iC4H10 10.25 -1.41 0.9 0.012 nC4H10 10.6 0.02 0.9 0.012 iC5H12 9.91 -1.91 1.1 0.008 nC5H12 10.86 -2.12 1.1 0.007 表 5 13434批酸解烃样品质量控制结果
Table 5. Analytical results on quality control of 13434 batch acidolysis hydrocarbon samples
组分 标准气体管理样 重复样 标准值
(μL/L)平均值
(μL/L)相对误差
(%)RSD
(%)合格率
(%)相对偏差
(%)平均值
(%)合格率
(%)CH4 99.5 99.59 0.09 1.5 100 0.01~19.66 7.81 100 C2H6 10.0 9.79 -2.05 4.5 100 0.12~29.14 4.94 100 C2H4 9.6 9.52 -0.88 5.3 100 0.00~0.46① 0.09① 100 C3H8 10.4 10.43 0.27 2.6 100 0.00~32.01 5.04 99 C3H6 10.0 9.89 -1.12 5.1 100 0.00~0.33① 0.06① 100 iC4H10 10.4 10.29 -1.10 3.5 100 0.07~42.29 13.91 90 nC4H10 10.6 10.66 0.53 4.9 100 0.09~38.50 13.17 92 iC5H12 10.1 10.17 0.71 2.9 100 0.15~23.22 7.65 100 nC5H12 11.1 11.15 0.47 2.7 100 0.19~34.97 11.98 97 注:标注① 的单位为μL/kg(样品中C2H4、C3H6含量均 < 1.0 μL/kg)。 -
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