盐卤是铷(Rb)的主要资源之一， 针对盐卤中Rb的分析存在基体效应的问题， 研究了石墨炉中盐卤氯化物(NaCl， CaCl2， KCl和MgCl2)的基体效应对Rb的前向简并四波混频(Forward phase-matching degenerate four-wave mixing， FDFWM)信号的影响特性。 通过研究FDFWM信号随Rb浓度、 盐卤氯化物浓度的变化特性， 发现FDFWM信号随着Rb样品浓度的增大， 先增大后减少， 在80 ng·mL-1时， 达到最大； 在Rb的浓度较低时， 盐卤氯化物对FDFWM信号存在明显抑制作用； 在Rb浓度较高时， 盐卤氯化物对信号先增强后抑制， 当其浓度约为Rb浓度的10倍时， 信号达到最大。 根据石墨炉中Cl离子的气相干扰和Rb原子的电离两方面对实验结果进行了很好的解释。 本研究结果对使用FDFWM方法在盐卤中提取和分析Rb有重要的意义。

Rb is mainly extracted from brine. The authors studied the matrix effect of chloride brine (NaCl,CaCl2,KCl and MgCl2) on FDFWM (Forward phase-matching degenerate four-wave mixing) of Rb in the graphite furnace. The Rb and other chloride brine concentrations dependences of FDFWM were investigated respectively. The results indicate that with the increase in Rb concentration, FDFWM increases and reaches the highest at 80 ng·mL-1. With the concentration of Rb sample further increasing, the FDFWM intensity drops. It was also found that when the Rb concentration is low, FDFWM signal is suppressed by the chloride brine, and the suppressing effect gets stronger with the increase in the chloride brine concentration. However, when the Rb concentration is high, FDFWM signal is first enhanced and then suppressed with the increase in the chloride brine concentration. The Cl- interference and Rb ionization in the graphite furnace were employed to explain the experimental results. This work is of important meaning in extracting and analyzing Rb in brine.