电感耦合等离子体原子发射光谱法测定天然气中微量金属元素分析系统研究

摘要

An effective analysis system based on sampling with solution absorption device is studied for the determination of trace metals in natural gas by inductively coupled plasma atomic emission spectrometry (ICP‐AES) .The quartz absorption device with diameter of 80 mm and height of 130 mm shows a lower interference and high absorption . The storing sample bottle after soaking overnight with 10% nitric acid solution has a lower impact on the measurement results .The sampling flow of 0 .5 L/min displays a better absorption effect and good representative sample . Under the optimized experimental conditions of ICP‐AES ,such as the pump speed ,RF power ,nebulizer gas flow ,auxiliary gas flow ,integration time and rinsing time ,as well as characteristic wavelength ,the analysis system exhibits high sensitivity (the detection limits of 22 elements from 0 .1-31 .4 μg/L) . T he calibration curve is a good linearity in the range of 50 .0 -1 000 .0 μg/L . T he features of the developed system include high absorption efficiency ,simple structure ,small size ,easy operation , wide measurement range ,and low detection limit with a potential for determination of trace metals in natural gas .%研究了用溶液吸收装置对天然气中微量金属元素进行取样，采用电感耦合等离子体（ICP）原子发射光谱法测定其浓度的分析系统。石英材质溶液吸收装置的直径为80mm、高为130mm，具有较低的干扰和良好的吸收效果。用10％（φ）硝酸溶液浸泡过夜处理后的样品储存瓶对测定结果具有较低的影响。采样流量为0．5L／min时，具有较好的吸收效果和样品代表性。研究优化了ICP发射光谱仪泵速、RF功率、雾化器气体流量、辅助气气体流量、积分时间和冲洗时间等分析条件，以及特征波长。分析系统在此优化条件下显示出高的灵敏度（22种元素检出限从0．1～31．4μg／L）。校准曲线在50．0～1000．0μg／L范围内显示出良好的线性。该分析系统吸收效率高、结构简单、尺寸小、操作简便、测定范围宽、检出限低，是一种有潜力的天然气中微量金属元素测定系统。