一种基于正交试验的液化石油气检测方法研究

Liquefied petroleum gas detection method based on orthogonal experimental design

建立了液化石油气的毛细管柱气相色谱测定方法,用正交试验法筛选出优化试验条件。在优化条件下,液化石油气样品在10 min内完成分析,液化石油气3个主要成分丙烷、异丁烷及正丁烷的检出限(S/N=3)分别为0.428 2、0.488 6、0.639 3 ng,定量下限(S/N=10)分别为1.427、1.629、2.131 ng,分别在1.338×105～1.982×105、1.719×105～2.595×105 ng和1.776×105～2.595×105ng范围内线性关系良好(r分别为0.999 3、0.999 0、0.999 6)。该方法操作简便、灵敏度高、重复性好,可用于液化石油气的测定。

A method for the determination of liquefied petroleum gases （LPG） is established by capillary gas chromatography.The optimum experimental conditions are obtained by using orthogonal design.LPG samples are separated on a SE-30 at 35℃ and detected by a flame ionization detector （FID） at 200℃.Other experimental condition are as follows：nitrogen as carrier gas at a flow rate of 1.0 ml/min,30∶1 of split flow ratio,150℃ of the injector temperature.Under optimum conditions,a separation run of a LPG sample can be finished within 10 min.The proposed method allows the determination of the main components of LPG in the linear range are 1.338 × 105-1.982 × 105 ng （r =0.999 3） for propane,1.719 × 105-2.595 × 105 ng（r =0.999 0） for isobutane,1.776 × 105-2.594 × 105 ng （r =0.999 6） for n-butane.The detection limits are 0.428 2 ng for propane,0.488 6 ng for isobutane,0.639 3 ng （3σ） for n-butane.The minimum detection limits are 1.427 ng,1.629 ng and 2.131 ng.The method is simple,fast,accurate,and suitable for the determination of the major chemical components of LPG.