This research investigates the potential of near infrared spectroscopy (NIRS) for the detection and quantification of pesticides in aqueous solution. Standard solutions of Alachlor and Atrazine (ranging in concentrati...This research investigates the potential of near infrared spectroscopy (NIRS) for the detection and quantification of pesticides in aqueous solution. Standard solutions of Alachlor and Atrazine (ranging in concentration from 1.25 - 100 ppm) were prepared by dilution in a Methanol/water solvent (1:1 methanol/water (v/v)). Near infrared transmission spectra were obtained in the wavelength region 400 - 2500 nm;however, the wavelength regions below 1300 nm and above 1900 nm were omitted in subsequent analysis due to the poor signal repeatability in these regions. Partial least squares analysis was applied for discrimination between pesticide and solvent and for prediction of pesticide concentration. Limits of detection of 12.6 ppm for Alachlor and 46.4 ppm for Atrazine were obtained.展开更多
Temperature-dependent near-infrared(NIR) spectroscopy is a new technique for measuring the NIR spectra of a sample at different temperatures. Taking the advantage of the temperature effect, the technique has shown its...Temperature-dependent near-infrared(NIR) spectroscopy is a new technique for measuring the NIR spectra of a sample at different temperatures. Taking the advantage of the temperature effect, the technique has shown its potential in both quantitative and qualitative analysis. The technique has been proved to be powerful in determination of the analytes in complex samples,particularly in studying the functions of water in aqueous systems due to the significant effect of temperature on the NIR spectra of water. Because of the complicated interactions in the samples and the overlapping of the broad peaks in NIR spectra, it is difficult to extract the temperature-dependent information from the spectra. Chemometric methods, therefore, have been developed for improving the spectral resolution and extracting the temperature-induced spectral information. In this review, recent advances in the studies of chemometric methods and the applications in resolution, quantitative and structural analysis of temperature-dependent NIR spectra were summarized.展开更多
Water quality assessment is currently based on time-consuming and costly laboratory pro-cedures and numerous expensive physicochemical sensors deployment.In response to the trend of device minimization and reduced out...Water quality assessment is currently based on time-consuming and costly laboratory pro-cedures and numerous expensive physicochemical sensors deployment.In response to the trend of device minimization and reduced outlays in sustainable aquaponic water monitoring,the integration of aquaphotomics and computational intelligence is presented in this paper.This study used the combination of temperature,pH,and electrical conductivity sensors in predicting crop growth primary macronutrient concentration(nitrate,phos-phate,and potassium(NPK)),thus,limiting the number of deployed sensors.A total of 220 water samples collected from an outdoor artificial aquaponic pond were temperature perturbed from 16 to 36℃ with 2℃ increments to mimic ambient range,which varies water compositional structure.Aquaphotomics was applied on ultraviolet,visible light,and near-infrared spectral regions,100 to 1000 nm,to determine NPK compounds.Princi-pal component analysis emphasized nutrient dynamics through selecting the highly corre-lated water absorption bands resulting in 250 nm,840 nm,and 765 nm for nitrate,phosphate,and potassium respectively.These activated water bands were used as wave-length protocols to spectrophotometrically measure macronutrient concentrations.Exper-iments have shown that multigene symbolic regression genetic programming(MSRGP)obtained the optimal performance in parameterizing and predicting nitrate,phosphate,and potassium concentrations based on water physical properties with an accuracy of 87.63%,88.73%,and 99.91%,respectively.The results have shown the established 4-dimensional nutrient dynamics map reveals that temperature significantly strengthens nitrate and potassium above 30℃ and phosphate below 25℃ with pH and electrical con-ductivity ranging between 7 and 8 and 0.1 to 0.2 mS cm^(-1) respectively.This novel approach of developing a physicochemical estimation model predicted macronutrient concentra-tions in real-time using physical limnological sensors with a 50%reduction of energy consumption.This展开更多
文摘This research investigates the potential of near infrared spectroscopy (NIRS) for the detection and quantification of pesticides in aqueous solution. Standard solutions of Alachlor and Atrazine (ranging in concentration from 1.25 - 100 ppm) were prepared by dilution in a Methanol/water solvent (1:1 methanol/water (v/v)). Near infrared transmission spectra were obtained in the wavelength region 400 - 2500 nm;however, the wavelength regions below 1300 nm and above 1900 nm were omitted in subsequent analysis due to the poor signal repeatability in these regions. Partial least squares analysis was applied for discrimination between pesticide and solvent and for prediction of pesticide concentration. Limits of detection of 12.6 ppm for Alachlor and 46.4 ppm for Atrazine were obtained.
基金supported by the National Natural Science Foundation of China(21475068,21775076)
文摘Temperature-dependent near-infrared(NIR) spectroscopy is a new technique for measuring the NIR spectra of a sample at different temperatures. Taking the advantage of the temperature effect, the technique has shown its potential in both quantitative and qualitative analysis. The technique has been proved to be powerful in determination of the analytes in complex samples,particularly in studying the functions of water in aqueous systems due to the significant effect of temperature on the NIR spectra of water. Because of the complicated interactions in the samples and the overlapping of the broad peaks in NIR spectra, it is difficult to extract the temperature-dependent information from the spectra. Chemometric methods, therefore, have been developed for improving the spectral resolution and extracting the temperature-induced spectral information. In this review, recent advances in the studies of chemometric methods and the applications in resolution, quantitative and structural analysis of temperature-dependent NIR spectra were summarized.
文摘Water quality assessment is currently based on time-consuming and costly laboratory pro-cedures and numerous expensive physicochemical sensors deployment.In response to the trend of device minimization and reduced outlays in sustainable aquaponic water monitoring,the integration of aquaphotomics and computational intelligence is presented in this paper.This study used the combination of temperature,pH,and electrical conductivity sensors in predicting crop growth primary macronutrient concentration(nitrate,phos-phate,and potassium(NPK)),thus,limiting the number of deployed sensors.A total of 220 water samples collected from an outdoor artificial aquaponic pond were temperature perturbed from 16 to 36℃ with 2℃ increments to mimic ambient range,which varies water compositional structure.Aquaphotomics was applied on ultraviolet,visible light,and near-infrared spectral regions,100 to 1000 nm,to determine NPK compounds.Princi-pal component analysis emphasized nutrient dynamics through selecting the highly corre-lated water absorption bands resulting in 250 nm,840 nm,and 765 nm for nitrate,phosphate,and potassium respectively.These activated water bands were used as wave-length protocols to spectrophotometrically measure macronutrient concentrations.Exper-iments have shown that multigene symbolic regression genetic programming(MSRGP)obtained the optimal performance in parameterizing and predicting nitrate,phosphate,and potassium concentrations based on water physical properties with an accuracy of 87.63%,88.73%,and 99.91%,respectively.The results have shown the established 4-dimensional nutrient dynamics map reveals that temperature significantly strengthens nitrate and potassium above 30℃ and phosphate below 25℃ with pH and electrical con-ductivity ranging between 7 and 8 and 0.1 to 0.2 mS cm^(-1) respectively.This novel approach of developing a physicochemical estimation model predicted macronutrient concentra-tions in real-time using physical limnological sensors with a 50%reduction of energy consumption.This
