Application And Research Of Spectrum Interference Correction Methods In Emission Spectrometer

Inductively Coupled Plasma Optical Emission Spectrometer is a kind of lab analysis instruments, which is mainly used to precisely test some corresponding parameters, such as concentration of samples, using the principle and methods of emission spectroscopy. The original usage of ICP-OES is in metallurgy, geology, mine and petrifaction, to detect trace elements'concentrations in mineral or its productions, and to make sure their physical and chemical characteristics and aftertreatment. Nowadays, its usage has been extended to life science, environmental detection, food safety, organic analysis, and so on, because of its higher detecting sensitivity and lower detecting limit.Under the consideration of this instrument, the long term task is to improve detection sensitiveness, farther reduce detecting limit, and improve its stability. The main restrictions to accomplish the tasks above are spectrum interferences and non-spectrum interferences, because those interferences make the lines which could be recognized originally cannot be identified or the spectrum intensity cannot be made sure. Lots of ameliorations in sampling methods, RF power supplies, plasma intercepting device, optical systems and detectors can revise or weaken the non-spectrum interferences, but spectrum interferences still exist and such problems as background interferences, lines superposing and lines excursion are obvious, so amelioration in spectrum analyzing methods is indispensable. The traditional and common spectrum analyzing methods nowadays are summed up and it was found that Kalman Filtering method is so useful that it can solve all spectrum problems ever found, and lots of methods are complex in computing and line fitting method can be ameliorated further in correcting precision. So it is necessary to research on the methods of Kalman Filtering, Fast Spectrum Analyzing and Gaussian curvefitting after enhancing spectrum data.The main contents of the thesis are: Firstly, this paper analyzes spectrum interferences and non-spectrum interferences in ICP-OES, and the key point of problem locates on spectrum analyzing arithmetic methods. The traditional and common spectrum analyzing methods nowadays are summed up and compared with one another in characteristics and performances. Secondly, Kalman Filtering method is adopted to analyze and revise spectrums. It has been used to revise Gaussian white noises, background interferences, lines superposing and lines excursion. Thirdly, Fast Spectrum Analyzing method is adopted to analyze and revise spectrums. It has been used to fast revise background interferences and lines superposing when Gaussian white noise has been ignored and lines excursion has already been revised. Emulation proves that this method can compute in higher speed, and at the same time can give precise results. Lastly, Gaussian curvefitting with spectrum data enhancing method is adopted to analyze and revise spectrums. Spectrum data enhancing method is used to enrich original emission spectrum data, improve lines'data resolution, so lines can be identified and separated more easily. Gaussian curvefitting method is used to separate and fit two peaks and three peaks, and the fitting error is in the range of permission. Results prove that the method is effective and feasible.In this paper, three spectrum analyzing methods are adopted to revise spectrum interferences in ICP-OES. Kalman Filtering method can correct all spectrum interferences ever found, and Fast Spectrum Analyzing method can revise background interferences and lines overlapping in shorter time, and Gaussian curvefitting with spectrum data enhancing method performs better in multi-line separation, meanwhile, its computing speed and precision have been improved.