摘要：
It is not necessary to digest a sample if it is determined by Arc Direct Reading Emission Spectrometry, and multiple elements can be simultaneously determined by solid injection.Currently used geochemical solid buffers, such as potassium persulfate and sodium fluoride have a low temperature arc flame, and can only analyze silver, boron, tin, molybdenum, lead, copper and other volatile elements but cannot analyze chromium, manganese, titanium and other high boiling point elements.Alkali metal was used to control the low arc temperature, and a solid buffer composed of aluminum fluoride, PCTFE and other high efficiency fluorination compounds was prepared based on the fact that the reaction between difficult volatile elements and fluorine ion under high temperature would have lower excitation energy.By optimizing the choice of line pairs, exposure time, electrode shape and other analysis conditions, 14 volatile and non-volatile elements in the geochemical samples can be simultaneously analyzed.The detection limit of the method ranges from 0.016 to 46.93 μg/g, and the relative standard deviation is 4.1% to 12.3%.The accuracy was verified by national standard material.The results were in accordance with the standard values, and the parameters meet the requirements of geochemical census.The method has high analysis efficiency and is practical in geochemical analysis.%应用电弧直读发射光谱法测定化探样品,样品无需消解,采用固体进样的方式可以同时测定多个元素.但目前化探分析中常采用的固体缓冲剂(如焦硫酸钾、氟化钠)的电弧温度较低,只能分析银、硼、锡、铅、钼、铜等易挥发元素,而不能分析铬、锰、钛等沸点较高的难挥发性元素.本文通过碱金属控制较低的电弧温度,并利用难挥发元素能在高温条件下与氟离子发生化学反应降低其激发温度,配制了一种以氟化铝、聚三氟氯乙烯等氟化效率较高的化合物为主要成分的固体缓冲剂,通过优化分析线对的选择、曝光时间、电极形状等分析条件,实现了一次制样可同时分析地球化学样品中14种易挥发和难挥发元素.方法检出限为0.016~46.93 μg/g,相对标准偏差为4.1%~12.3%,通过国家标准物质验证了准确度,测定值与标准值相符,各项参数都能满足地球化学普查规范要求.本方法分析效率高,在化探分析中具有一定的实用性.
