On-line monitoring of multiple component parameters during ethanol fermentation by near-infrared spectroscopy / 生物工程学报

The quantity of biomass, glucose concentration and ethanol concentration are important parameters in ethanol fermentation. Traditional methods are usually based on samples for off-line measurement, which not only requires multiple instruments for test and analysis but also consumes notable time and effort, and therefore is inconvenient for real-time process control and optimization. In this study, an in-situ detection method based on the near-infrared (NIR) spectroscopy is proposed for measuring the above process parameters in real time. The in-situ measurement is carried out by using an immersion type NIR spectroscopy. A multi-output prediction model for simultaneously estimating the quantity of glucose, biomass and ethanol is established based on a multi-output least-squares support vector regression algorithm. The experimental results show that the proposed method can precisely measure the quantity of glucose, biomass and ethanol during the ethanol fermentation process. Compared to the existing partial-least-squares method for modeling and prediction of individual components, the proposed method could evidently improve the measurement accuracy and reliability.

Development of Dipolar Proton Transfer Reaction Mass Spectrometer for Real-time Monitoring of Volatile Organic Compounds in Ambient Air / 分析化学

Volatile organic compounds (VOCs) in ambient air can participate in photochemical reactions, which lead to the generation of secondary pollutants such as ozone and aerosol. So real-time and accurate monitoring of atmospheric VOCs plays an important role in the study of the causes of air pollution. On the basis of proton transfer reaction mass spectrometry (PTR-MS) research, a novel dipolar proton transfer reaction mass spectrometer (DP-PTR-MS) for real-time and on-line monitoring atmospheric VOCs was developed. Compared with the conventional PTR-MS with one kind of reagent ion H3O+, DP-PTR-MS had three kinds of reagent ions H3O+, OH-, (CH)2COH+, which could be switched according to the actual detection need. So DP-PTR-MS can improve the qualitative ability and expand the detection range effectively. The reagent ion H3O+can be used for detecting VOCs whose proton affinities are greater than that of H2O. The reagent ion OH-can be used to identify VOCs cooperating with the reagent ion H3O+,and can also be used for detecting some inorganic substances such as CO2. The reagent ion (CH3)2COH+can be used for accurately detecting NH3under interference elimination circumstances. The limit of detection (LOD) and sensitivity of DP-PTR-MS were measured by using six kinds of standard gases. The results showed that the LOD for detecting toluene was 7×10-12(V/V) and the sensitivity for detecting ammonia has reached 126 cps/10-9 (V/V). The ambient air in Hefei city was on-line and real-time monitored for continuous 78 hours with DP-PTR-MS. The results showed that the newly developed DP-PTR-MS could be used for long-term and real-time monitoring atmospheric VOCs with the concentration of 10-12(V/V) level. DP-PTR-MS is an important tool for the study of the causes of atmospheric pollution and the monitoring of trace VOCs emissions.

On-line monitoring of biomass in 1,3-propanediol fermentation by Fourier-transformed near-infrared spectra analysis / 生物工程学报

Biomass is an important parameter reflecting the fermentation dynamics. Real-time monitoring of biomass can be used to control and optimize a fermentation process. To overcome the deficiencies of measurement delay and manual errors from offline measurement, we designed an experimental platform for online monitoring the biomass during a 1,3-propanediol fermentation process, based on using the fourier-transformed near-infrared (FT-NIR) spectra analysis. By pre-processing the real-time sampled spectra and analyzing the sensitive spectra bands, a partial least-squares algorithm was proposed to establish a dynamic prediction model for the biomass change during a 1,3-propanediol fermentation process. The fermentation processes with substrate glycerol concentrations of 60 g/L and 40 g/L were used as the external validation experiments. The root mean square error of prediction (RMSEP) obtained by analyzing experimental data was 0.341 6 and 0.274 3, respectively. These results showed that the established model gave good prediction and could be effectively used for on-line monitoring the biomass during a 1,3-propanediol fermentation process.

Establishment of near-infrared on-line monitoring model and determination of endpoint in frying process of Hordei Fructus Germinatus / 中国中药杂志

Hordei Fructus Germinatus has been always used by "stir-frying" as a traditional medicine and the endpoint judgment of "fragrant" and "yellow" has been the focus and difficulty in frying process research. In this study, a quantitative calibration model between index components and NIRS was established in order to rapidly detect the contents of reducing sugar, total amino acids, total flavonoids, A420 and moisture; besides, an endpoint judgment method of frying process was put forward based on the "component change rate". Near-infrared spectra of samples with different frying time were collected, and a quantitative analysis model based on near-infrared spectroscopy was established to optimize the parameters such as spectral pretreatment and modeling band. HCA and PLS-DA were used to study the relationship between component and "stir-frying", and the endpoint of frying process was determined. The established calibration model had a good performance that the correlation coefficients between the predicted results and the actual measured values were both more than 0.9, with predicted relative deviations less than 10%. Hordei Fructus Germinatus with different frying time was divided into 4 categories by HCA analysis. PLS-DA analysis showed that total reducing sugar had a significant contribution to distinguishing the Hordei Fructus Germinatus of different frying time. When the change rate of total reducing sugar was 80%, it could judge that the endpoint of frying had been obtained. Results showed that NIRS could not only quickly and accurately determine the contents of reducing sugar, total amino acid, total flavonoid, A420 and moisture in Hordei Fructus Germinatus samples of different frying time, but also judge the endpoint of frying in the process. This study provided a new method for the evaluation and endpoint judgment of "stir-frying" process in research of traditional Chinese medicine.

Research progress of on-line monitoring technology for drug powder blending process / 中国药学杂志

Blending process is one of the key links of the pharmaceutical process, since the uniformity of drug products not only affects the appearance but also influences homogeneity and stability of the intrinsic quality, and then affects the efficacy of the products. Therefore, to ensure the safety and effectiveness of drugs, it is necessary to analyze and control the uniformity of the drug powder in the process of blending. Compared with the traditional method for the end point determination of the blending process, online monitoring technology has obvious advantages and broad application prospects. This paper summarized the research progress of online monitoring technologies for blending process in the pharmaceutical industry. Firstly, four kinds of online monitoring technologies were introduced and compared, which were the near infrared spectroscopy, thermal sensing technology, Raman spectroscopy and chemical imaging technology. Then the methods and principles of on-line monitoring algorithms were summarized and expounded. After that, a brief introduction of the application of near infrared monitoring equipment for pharmaceutical blending process was given. And then the research progress of the online monitoring of the blending process in the domestic pharmaceutical industry was summarized. Finally, the development trend of online monitoring technology of blending process was looked into the future.

On-line monitoring of extraction of coldrine by near-infrared spectrum / 中国中药杂志

Extraction of the four Chinese herbals is the beginning step of the production process of coldrine granules and influences on drug quality significantly. In this paper, the on-line near infrared spectrum was collected during the extraction process of coldrine and then pre-processed by the first derivative. Partial least square regression (PLSR) model was developed for the quantity indicators of linarin, chlorogenic acid and solid content, according to results of both HPLC and weight-loss as reference methods. The correlation coefficient, root mean square error of cross-validation (RMSECV), root mean square error of calibration (RMSEC) and root mean square error of prediction (RMSEP) were used to optimize model parameters and confirm their performance. Correlation coefficients of three quality control indicator models reached more than 0.95.Values of RMSEC of linarin, chloroenic acid and solid content were 0.010 4, 0.009 34 and 0.055 5, respectively. And the values of RMSEP were 0.009 47, 0.142 and 0.008 42, respectively. The models, built on-line analyze data, revealed that the correlation coefficients of predicted values and measured values were greater than 0.97 and values of RSEP of linarin, chloroenic acid and solid content were 8.14%, 8.17% and 9.86%, respectively. The results showed that the NIR method could achieve the on-line detection and real-time monitoring of multi-indexes during the extraction process of coldrine. The technology could be used for drug quality control in the process of practical production, reducing the batch differences and ensuring pharmaceutical quality stability. In addition, it could provide real-time production data for subsequent product quality backtracking.

Design of automatic reverse osmosis water system / 中国医学装备

Objective:To design automatic reverse osmosis water system with new design idea of reverse osmosis water system, to make sure of the procedure. Methods:During the design, using microcomputer technology to control water preparation and disinfection. Results:Using MCU to control preparation of water and disinfection, in order to monitor water quality. If water quality exceeds the standard, the system will alarm and generate records. Conclusion: Using microcomputer technology to design Reverse osmosis water system, not only reducing artificial, but also to improve the safety and controllability, even the quality control of reverse osmosis water system.

On-line monitoring of traditional Chinese medicinal powder blending process by using near-infrared spectroscopy / 中国药学杂志

OBJECTIVE: To establish a rapid method based on near-infrared diffuse reflectance spectroscopy (NIR) to monitor the blending process of traditional Chinese medicinal powder on-line. METHODS: NIR spectra were collected during the blending processes of mixtures consisting of Red Peony Root powder and defatted Spine Date Seed powder. Multivariate calibration models based on PLS regression were developed to correlate the collected spectra with the content of Red Peony Root powder. The optimal calibration model was applied to monitor the blending process in real time with noninterference. RESULTS: After spectral pretreatment using multiplicative signal correction (MSC), first derivative and Savitzky-Golay filter, Red Peony Root powder contents were quantified using PLS algorithm in the spectral ranges of 5900-5950 cm-1, 6700-6750 cm-1 and 6950-7100 cm-1. The correlation coefficient of the calibration model was 0.9990. The RMSEC, RMSEP and RMSECV were 1.14, 1.16 and 1.26, respectively. CONCLUSION: It was demonstrated that a miniature near-infrared analyzer could be used to monitor the contents of the constituents and the blending homogeneity of traditional Chinese medicinal powder in real time, and to rapidly determine the end-point of blending process. In addition, it can be used to judge whether the physical state of powder mixture conforms to the standard. Therefore, NIR spectroscopy is considered to be an appropriate PAT tool for end-point control of blending process of traditional Chinese medicinal powder.

On-line detecting of transformer winding deformation based on parameter identification of leakage inductance / 药物分析学报

Transformers are required to demonstrate the ability to withstand short circuit currents. Over currents caused by short circuit can give rise to windings deformation. In this paper, a novel method is proposed to monitor the state of transformer windings, which is achieved through on-line detecting the leakage inductance of the windings. Specifically, the mathematical model is established for on-line identifying the leakage inductance of the windings by applying least square algorithm (LSA) to the equivalent circuit equations. The effect of measurement and model inaccuracy on the identification error is analyzed, and the corrected model is also given to decrease these adverse effect on the results. Finally, dynamic test is carried out to verify our method. The test results clearly show that our method is very accurate even under the fluctuation of load or power factor. Therefore, our method can be effectively used to on-line detect the windings deformation.

On-line detecting of transformer winding deformation based on parameter identification of leakage inductance / 西安交通大学学报·英文版

Transformers are required to demonstrate the ability to withstand short circuit currents. Over currents caused by short circuit can give rise to windings deformation. In this paper, a novel method is proposed to monitor the state of transformer windings, which is achieved through on-line detecting the leakage inductance of the windings. Specifically, the mathematical model is established for on-line identifying the leakage inductance of the windings by applying least square algorithm (LSA) to the equivalent circuit equations. The effect of measurement and model inaccuracy on the identification error is analyzed, and the corrected model is also given to decrease these adverse effect on the results. Finally, dynamic test is carried out to verify our method. The test results clearly show that our method is very accurate even under the fluctuation of load or power factor. Therefore, our method can be effectively used to on-line detect the windings deformation.