Peak conversion method of three-dimensional spectroscopic data under different photomultiplier tube voltages

Abstract

The invention discloses a peak conversion method of three-dimensional fluorescence spectra under different photomultiplier tube voltages. The method includes two steps of numerical correction and peak conversion. Numerical correction includes: setting the determination conditions; respectively determining three-dimensional three-dimensional fluorescence spectra of deionized water and a calibration reagent quinine sulfate; reading a Rayleigh scattering value in the three-dimensional fluorescence spectrum of deionized water at the excitation wavelength Ex equal to emission wavelength Em of 350 nm and the peak of the quinine sulfate solution under the same conditions (PMT voltage, excitation-emission scanned area); and conducting linear fitting of the two values, and determining the accuracy of the three-dimensional fluorescence data according to the results of the linear fitting. Peak conversion includes: conducting linear fitting of the peak of a sample under a known voltage and specific wavelength range and the Rayleigh scattering value in the three-dimensional fluorescence spectrum of deionized water at the excitation wavelength Ex equal to emission wavelength Em of 350 nm under corresponding voltage; and converting the peak of the sample into corresponding peaks under different voltages according to the obtained linear equation.

Description

technical field [0001] The invention relates to a method for peak conversion of three-dimensional spectral data under different voltages of photomultiplier tubes. The method includes two steps of numerical correction and peak conversion. The scattering value of water is skillfully used to quantitatively evaluate the power of different photoelectric multiplier tubes. innovative. The conversion of the peak value of the three-dimensional fluorescence spectrum under different photomultiplier tube voltages can be realized quickly, accurately and efficiently. Background technique [0002] Three-dimensional fluorescence spectroscopy (also known as total luminescence spectrum or excitation-emission diagram) is a new analysis technology developed on the basis of fluorescence spectroscopy analysis in the 1980s. It can not only improve measurement sensitivity and selectivity to molecular structure, Moreover, it can display the fluorescence information of the sample more comprehensivel...

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Problems solved by technology

[0003] For fluorescence data, there are generally related calibration steps before analysis. The first is to correct the spectral properties of the instrument. characteristics, not the real spectrum of the fluorescent substance itself; followed by the correction of the absorption properties of the sample (usually an internal filtering effect); but through the first two steps, the intensity of the fluorescent signal is not corrected, in the same case, the The position of the peak will be affected by the photomultiplier tube of the instrument, and the intensity of the fluorescent signal is also very dependent on the photomultiplier tube voltage

However, this last critical correction step is often overlooked

[0004] At present, there are very few studies on the calibration method of fluorescence intensity based on different photomultiplier tube voltages. Some literatures propose to use the Raman peak area of ​​water ( figure 1 The abscissa in the middle circle is the peak around 400nm) to correct (see the paper A.J.Lawaetz and C.A.Stedmon. J Applied Spectroscopy, 2009, 63(8) 936-940), figure 1 The small picture in the middle is the enlarged picture of the Raman peak. It can be seen that there are many interference noises at 400nm. The specific position of the Raman peak is difficult to accurately determine, and the spectrum is affected by the calculation method and the curve smoothing method when calculating the peak area. high error

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