等离子体发射光谱法中微量雾化器的应用

Application of Microflow Nebulizer in Inductive Coupled Plasma Atomic Emission Spectrometry

应用电感耦合等离子体发射光谱法测定环境或生物样品如悬浮颗粒物、浮游植物和沉积物提取物中金属元素时常面临试样较少的问题。在等离子体发射光谱仪上使用微量雾化器,利用金属元素标准溶液对仪器工作条件如雾化器压力、射频功率、输出泵速、辅助气流量进行了实验,获得最优工作条件为:雾化器压力0.2MPa,射频功率1 150W,输出泵速25r/min,辅助气流量0.5L·min-1。在该工作条件下,与常量雾化器的信号强度、背景值、方法检出限进行比较,信号强度略有降低,背景值明显降低,检出限与常量雾化器相当。应用微量雾化器对海洋沉积物提取样、浮游植物消解样、悬浮颗粒物消解样中的Al、Fe、Mg、Mn、Ti、Ba、Sr、Co、Cu、Ni进行了测定,结果与常量雾化器所测值进行了对比,发现无明显差异,且其背景值降低,减小了元素测定的背景干扰。样品消耗量仅为常量雾化器的1/3或更少,分析效率得以提高,是解决少量环境样品测试的有效方法。

A microflow nebulizer was applied in an inductive coupled plasma atomic emission spectrometer （ICP-AES） to minimize the consumption of samples for environmental analyses. Experiments with metal element standard solutions were carried out on the related instrumental parameters, i. e. , the nebulizer gas pressure, the radio frequency （RF） generator power, the peristaltic pump rotary speed, and the auxiliary gas flow rate. The optimal working conditions were obtained as follows： the nebulizer gas pressure was 0. 2 MPa, the RF power was 1 150 W, the peristaltic pump rotary speed was 25 r/min, and the auxiliary gas flow rate was 0. 5 L. min -1. The response intensities,the background values and the detection limits using the microflow nebulizer were compared with those using a normal nebulizer under their optimal working conditions. Response intensity using the microflow nebulizer was slightly lower than that using the normal nebulizer, while the background value using the microflow nebulizer was decreased significantly comparing with that using the normal nebulizer. Detection limits and the standard deviation of the elements measured by the both nebulizer were comparable. Analytical results of Al , Fe, Mg, Mn, Ti, Ba, Sr, Co, Cu and Ni of an extract of a marine sediment sample, a digested phytoplankton sample, and a digested suspended particle sample determined with the microflow nebulizer were consistent with those determined with the normal nebulizer. The background interferences were reduced when the microflow nebulizer were used. Sample consumption was just a third of that using the normal nebulizer or much less. The analytical efficiency was thus improved after the microflow nebulizer applied in ICP-AES.