辉光放电质谱法相对灵敏度因子影响因素研究

Study on Impact Basics of Relative Sensitivity Factors of Glow Discharge Mass Spectrometry

本工作研究了辉光放电气体流速、放电电压和放电电流3个主要因素对辉光放电质谱法(GDMS)相对灵敏度因子(RSF)的影响。结果显示,在恒定的放电电流或放电电压下,重元素的RSF随放电气体流速的增大而增大,轻元素的RSF随放电气体流速的增加略微减小或不变;在恒定的放电气体流速下,多数元素的RSF基本不随放电电流和放电电压改变。在400mL/min放电气体流速下,分别测定了Fe、Co、Ti、Ni、Zn、Sn、Pb 7种不同基体标准物质部分元素的RSF,结果显示,同一元素在不同基体条件下RSF的差异较小,基体效应不明显。将进一步得到的不同基体下的平均RSF应用于2种铜锌合金标准物质元素组分的测定,其主要元素的测定值与标准值的相对百分差均不超过30%。

Three impact basics of the relative sensitivity factors（RSF）and the ion intensity of glow discharge mass spectrometry（GDMS）,including discharge current,voltage and gas flow rate,were investigated.The results showed that under constant discharge current or voltage conditions,the RSF of heavy elements increases while the gas flow rate increases,and the RSF of light elements decreases slightly or stabilizes.Under constant discharge current conditions,the ion intensity increases while the gas flow rate is from 300 mL/min to 400 mL/min,and the ion intensity decreases while the gas flow rate is from 400mL/min to 500mL/min.Under constant discharge voltage conditions,the ion intensity increases while the gas flow rate is from 300mL/min to 500mL/min.Under constant gas flow rate conditions,the RSF of most elements is stabilized while the discharge current and voltage are changed,and the ion intensity increases while thedischarge current and voltage increase.This means that the gas flow rate is the most important impact basic.The RSF of some elements was determined using the CRM of Fe,Co,Ti,Ni,Zn,Sn and Pb under the gas flow rate of 400mL/min.It was found that the RSF difference of the same element at different matrixes is tiny,and matrix effect isn＇t distinct. This helps to achieve accurate measurement using non matrix-matched RSF while the matrix-matched standards are lacking.The mean RSF at different matrixes was calculated to calibrate the measured values of a few elements of two Cu-Zn alloys.The relative difference of the corrected values and the standard values is under 30%.