气相色谱–火焰光度法测定进口天然气中4种形态硫

Determination of Four Forms of Sulfur in Imported Natural Gas by Gas Chromatography with Flame Photometric Detection

建立气相色谱–火焰光度法测定进口液化天然气中4种形态硫的方法。探讨了色谱柱、进样口温度、分流比、柱流速、升温程序和FPD检测器等对测定结果的影响。在优化的实验条件下,评价了方法的可靠性。4种形态硫化物的质量浓度在10.0~200.0μg/L范围内,其对数与峰面积对数呈良好的线性关系,线性相关系数r在0.983 3~0.999 2之间,检出限为1.7~7.7μg/L,测定结果的相对标准偏差为0.56%~0.68%(n=5)。用该法测定天然气形态硫标准气体,测定值与标准值相比,相对误差为–1.6%~–1.2%。该方法具有较高的准确度,可应用于进口天然气中4种形态硫的分析。

A method for the determination of four forms of sulfur in imported natural gas was developed by gas chromatography with pulsed fl ame photometric detection. The factors relevant to the lab results including the choice of column,the temperature of injection,the fl ow split ratio,the program of temperature,the FPD detection and the control of column speed were investigated and optimized. Under the optimized conditions,the proposed method showed that the logarithmic value of chromatographic peak had a linear relationship with the logarithmic value of four sulfur compounds ranging from 10.0 to 200.0 μg/L with correlation coefficient of 0.983 3–0.999 2,the detection limits were 1.7~7.7 μg/L. The relative standard deviations of determination results were 0.56% – 0.68%(n=5). Natural gas form sulfur standard gas was detected by this method, the relative error of measured value compared with the standard values was from –1.6% to –1.2%. The method has good accuracy and it can be used for the analysis of four forms of sulfur in imported natural gas.