扫描式电感耦合等离子体光谱仪谱线峰位移的机理研究

通过对扫描式电感耦合等离子体原子发射光谱仪(ICP-AES)出射光谱线峰位移(Δλ)的机理研究,发现温度的变化、波长的变化以及光谱仪机械的系统误差是产生谱线峰位移的主要因素,首次测量了谱线峰位移与波长变化之间的非线性函数关系曲线Δλ-λ,以及谱线峰位移与温度变化之间的非线性函数关系曲线Δλ-T,并用多项式方程表达了这些函数关系。本研究还发现,不同的光栅单色仪有近似相同的Δλ-λ函数关系曲线,但是Δλ-T的函数关系曲线却很不相同。利用这些非线性函数方程式,设计开发了扫描式ICP-AES光谱仪的智能波长校正装置(IWC),用它取代传统的局部恒温系统及谱线描迹法进行样品分析的结果表明,智能波长校正的ICP光谱仪(ICP-IWC)谱线峰定位精度高,具有省时、安全、结构简单的特点,有广阔的应用前景。

Machanistic investigation of peak drift of a sequential inductively coupled plasma spectrometers

Peak drifts of emission spectral lines recorded on a sequential ICP- AES spectrometer are the main factor that seriously decreases the precision and accuracy of sample determinations. The functional relationships between peak drift Δλ, and wavelength λ, temperautre T are found in this paper. The functional relationship curves Δλ-λ, and Δλ-T were determined and expressed in the form of polynomial equations. The present study indicates that the curves Δλ-λ for different monochromators are similar, but the curves Δλ-T for different monochromators are quite different. Based on the above- mentioned polynomial equations, an intelligent wavelength calibrating device (IWC) is developed for the sequential ICP spectrometer, which can replace a local thermostat of the sequential ICP-AES or the traditional line-profile method. The applications of the sequential ICP-IWC illustrate that the IWC device can significantly improve the precision of peak determination and have widespread prospects.