Laboratory for Spectrochemistry, Indiana University, Bloomington, IN 47405, USA; Analytical Chemistry, Institute of Hydrochemistry, Technische Universität München, Marchioninistrasse 17, 81377 Munich, Germany.
Laboratory for Spectrochemistry, Indiana University, Bloomington, IN 47405, USA.
Talanta. 2018 Apr 1;180:25-31. doi: 10.1016/j.talanta.2017.12.021. Epub 2017 Dec 11.
Matrix effects caused by Na and Al in the nitrogen Microwave-sustained, Inductively Coupled, Atmospheric-pressure Plasma (MICAP) were investigated. Easily ionizable elements, such as Na, can suppress or enhance the analyte signal; Al is shown here to produce a similar effect. The influence of these matrices was examined for 18 emission lines of 8 analyte atoms and ions having a wide range of excitation and ionization energies. The plasma operating conditions were fixed during all experiments at a total nitrogen flow of 19.4Lmin and a microwave power of 1.5kW. An Fe solution was used to determine the excitation temperature of the plasma by the Boltzmann plot method at selected matrix concentrations. In addition, vertical emission profiles of the plasma were measured. The matrix effect becomes worse at higher concentrations of an easily ionizable element. The effect is caused not only by a shift in ionization equilibrium but also by a possible change in plasma ionization temperature. Correction methods to reduce the matrix effects were tested and are discussed.
研究了氮微波持续感应耦合常压等离子体（MICAP）中 Na 和 Al 引起的基质效应。易电离元素，如 Na，可以抑制或增强分析物信号；Al 在此显示出类似的效果。研究了这些基质对具有广泛激发和电离能的 8 种分析物原子和离子的 18 条发射线的影响。在所有实验中，等离子体操作条件固定在总氮流量为 19.4Lmin 和微波功率为 1.5kW。使用 Fe 溶液在选定的基质浓度下通过玻尔兹曼图法确定等离子体的激发温度。此外，还测量了等离子体的垂直发射轮廓。在易电离元素的浓度较高时，基质效应变得更糟。这种影响不仅是由电离平衡的移动引起的，还可能是由等离子体电离温度的变化引起的。测试并讨论了用于减少基质效应的校正方法。
