原子发射光谱法中信背浓度比的推导与应用

基于原子发射光谱信号强度与CCD积分时间和样品浓度之间的线性关系, 推导并提出一种信背浓度比(SBCR)的新概念, 建立了检出限与SBCR之间的关系. 基于合理假设推导出最大积分时间、 最大信背比和最大信背浓度比等表达式, 并通过实验对模型进行了验证. 最后使用SBCR表征了低功率ArMPT对Cu元素的激发能力, 使其检出限由13.1 ng/mL降低至2.8 ng/mL.

Derivation and Application of Signal-to-background-to-concentration Ratio for Atomic Emission Spectrometry†

The concept of signal-to-background-concentration ratio(SBCR) was derived and proposed to be a useful tool for judgement of the excitation power of an atomic excitation source(e.g., MPT) for atomic spectrometry based on the linear relationship between signal intensity, CCD integration period and sample concentration. The relationship between detection limit and SBCR was derived according to the definition of detection limit. The predicted expressions of maximum integration period, maximum signal-to-background ratio, and maximum SBCR were derived based on reasonable assumptions. The above model was verified by experiments. Finally, the excitation capability of low-power ArMPT for copper was characterized by this SBCR method, and the detection limit of Cu was improved from 13.1 ng/mL to 2.8 ng/mL.