研究如何应用自动质谱退卷积定性系统(automated mass spectral deconvolution&identification system,AMDIS)拆分中药挥发油总离子流谱图中的重叠峰。通过水蒸气蒸馏法提取挥发油,GC-MS测定得到总离子流谱图,AMDIS对重叠峰进行解析...研究如何应用自动质谱退卷积定性系统(automated mass spectral deconvolution&identification system,AMDIS)拆分中药挥发油总离子流谱图中的重叠峰。通过水蒸气蒸馏法提取挥发油,GC-MS测定得到总离子流谱图,AMDIS对重叠峰进行解析。AMDIS能够初步分析总离子流谱图中大约含有多少化合物。而后,通过分析待鉴定化合物对应扫描点的提纯质谱图及该处原始质谱图与参考谱库中的各匹配项,可准确的对化合物进行定性或否定某些实际并不存在的化合物。进一步分析各化合物特征性碎片离子峰的变化规律,可确认之前的结果。研究结果表明AMDIS通过对待鉴定化合物对应扫描点谱图的提纯,可以有效的对重叠峰进行拆分,进而准确的定性。展开更多
The proposed method of spline wavelet overlapped peaks analysis is based on the model of wavelet multifrequency channel decomposition. If the suitable optimal wavelet basis and frequency scale value are selected, the ...The proposed method of spline wavelet overlapped peaks analysis is based on the model of wavelet multifrequency channel decomposition. If the suitable optimal wavelet basis and frequency scale value are selected, the useful information can be extracted from noised overlapped signal. Then, according to the linear relationship between individual components in blurred version, multiple linear regression in low frequency domain is employed to resolve highly overlapped peaks. The results show that even signal-to-noise (S/N) decreases to 0.2, relative errors of peak intensity are less than 12% and the sum of square deviations Q is less than 0.展开更多
A 2nd-order spline wavelet convolution method in resolving overlapped peaks is developed. It determines the number of peaks, peak positions and width through wavelet? convolution, then uses spline function to construc...A 2nd-order spline wavelet convolution method in resolving overlapped peaks is developed. It determines the number of peaks, peak positions and width through wavelet? convolution, then uses spline function to construct the resoluter, which is used to resolve overlapped peaks. Theoretical proof is given, and the selections of wavelets and parameters are discussed. It is proven that baseline separation can be achieved after processed, the relative errors of peak position and area are less than 0.2% and 4.0% respectively. It can be directly applied to seriously overlapped signals, noisy signals and multi-component signals, and the results are satisfactory. It is a novel effective method for resolution.展开更多
Currently, the analysis of acetone-butanol-ethanol (ABE) broths is performed using both High Performance Liquid Chromatography (HPLC) and Gas Chromatography (GC) for each sample since GC cannot be used in quantifying ...Currently, the analysis of acetone-butanol-ethanol (ABE) broths is performed using both High Performance Liquid Chromatography (HPLC) and Gas Chromatography (GC) for each sample since GC cannot be used in quantifying sugars and HPLC methods are not yet efficient enough to detect all components separately. In this study, a novel method was developed to quantify all main components present in ABE model solutions (acetone, butanol, ethanol, butyric acid, acetic acid, glucose and xylose) using only HPLC. Although the HPLC operating conditions were optimized to obtain the best possible resolution in HPLC chromatograms, it was observed that the peaks for butyric acid, acetone and ethanol overlapped. The same trend was observed for glucose and xylose. Using the asymmetric Gaussian fit, a program was written in MATLAB to detect the overlapped peaks, deconvolute them and calculate the area of each separated peak. The concentrations of each component were then calculated using the areas and the calibration curves for each component. Experimental results show that this method works well for the ABE model solutions and can be used to quantify all components in the solution when there are some overlapped peaks in the HPLC chromatograms.展开更多
Using a wavelet function as the filter function of Fourier self-deconvolution, a new method of resolving overlapped peaks, wavelet-Fourier self-deconvolution, is founded. The properties of different wavelet deconvolut...Using a wavelet function as the filter function of Fourier self-deconvolution, a new method of resolving overlapped peaks, wavelet-Fourier self-deconvolution, is founded. The properties of different wavelet deconvolution functions are studied. In addition, a cutoff value coefficient method of eliminating artificial peaks and wavelet method of removing shoulder peaks using the ratio of maximum peak to minimum peak is established. As a result, some problems in classical Fourier self-deconvolution are solved, such as the bad result of denoising, complicated processing, as well as usual appearance of artificial and shoulder peaks. Wavelet-Fourier self-deconvolution is applied to determination of multi-components in oscillographic chronopotentiometry. Experimental results show that the method has characteristics of simpler process and better effect of processing.展开更多
文摘研究如何应用自动质谱退卷积定性系统(automated mass spectral deconvolution&identification system,AMDIS)拆分中药挥发油总离子流谱图中的重叠峰。通过水蒸气蒸馏法提取挥发油,GC-MS测定得到总离子流谱图,AMDIS对重叠峰进行解析。AMDIS能够初步分析总离子流谱图中大约含有多少化合物。而后,通过分析待鉴定化合物对应扫描点的提纯质谱图及该处原始质谱图与参考谱库中的各匹配项,可准确的对化合物进行定性或否定某些实际并不存在的化合物。进一步分析各化合物特征性碎片离子峰的变化规律,可确认之前的结果。研究结果表明AMDIS通过对待鉴定化合物对应扫描点谱图的提纯,可以有效的对重叠峰进行拆分,进而准确的定性。
文摘The proposed method of spline wavelet overlapped peaks analysis is based on the model of wavelet multifrequency channel decomposition. If the suitable optimal wavelet basis and frequency scale value are selected, the useful information can be extracted from noised overlapped signal. Then, according to the linear relationship between individual components in blurred version, multiple linear regression in low frequency domain is employed to resolve highly overlapped peaks. The results show that even signal-to-noise (S/N) decreases to 0.2, relative errors of peak intensity are less than 12% and the sum of square deviations Q is less than 0.
基金This work was supported by the National Natural Science Foundation of China(Grant No.29975033)the Natural Science Foundation of Guangdong Province(Grant Nos.980340 and 001237).
文摘A 2nd-order spline wavelet convolution method in resolving overlapped peaks is developed. It determines the number of peaks, peak positions and width through wavelet? convolution, then uses spline function to construct the resoluter, which is used to resolve overlapped peaks. Theoretical proof is given, and the selections of wavelets and parameters are discussed. It is proven that baseline separation can be achieved after processed, the relative errors of peak position and area are less than 0.2% and 4.0% respectively. It can be directly applied to seriously overlapped signals, noisy signals and multi-component signals, and the results are satisfactory. It is a novel effective method for resolution.
文摘Currently, the analysis of acetone-butanol-ethanol (ABE) broths is performed using both High Performance Liquid Chromatography (HPLC) and Gas Chromatography (GC) for each sample since GC cannot be used in quantifying sugars and HPLC methods are not yet efficient enough to detect all components separately. In this study, a novel method was developed to quantify all main components present in ABE model solutions (acetone, butanol, ethanol, butyric acid, acetic acid, glucose and xylose) using only HPLC. Although the HPLC operating conditions were optimized to obtain the best possible resolution in HPLC chromatograms, it was observed that the peaks for butyric acid, acetone and ethanol overlapped. The same trend was observed for glucose and xylose. Using the asymmetric Gaussian fit, a program was written in MATLAB to detect the overlapped peaks, deconvolute them and calculate the area of each separated peak. The concentrations of each component were then calculated using the areas and the calibration curves for each component. Experimental results show that this method works well for the ABE model solutions and can be used to quantify all components in the solution when there are some overlapped peaks in the HPLC chromatograms.
文摘Using a wavelet function as the filter function of Fourier self-deconvolution, a new method of resolving overlapped peaks, wavelet-Fourier self-deconvolution, is founded. The properties of different wavelet deconvolution functions are studied. In addition, a cutoff value coefficient method of eliminating artificial peaks and wavelet method of removing shoulder peaks using the ratio of maximum peak to minimum peak is established. As a result, some problems in classical Fourier self-deconvolution are solved, such as the bad result of denoising, complicated processing, as well as usual appearance of artificial and shoulder peaks. Wavelet-Fourier self-deconvolution is applied to determination of multi-components in oscillographic chronopotentiometry. Experimental results show that the method has characteristics of simpler process and better effect of processing.
