ABSTRACT
Preprocess method of multiplicative scatter correction (MSC) was used to reject noises in the original spectra produced by the environmental physical factor effectively, then the principal components of near-infrared spectroscopy were calculated by nonlinear iterative partial least squares (NIPALS) before building the back propagation artificial neural networks method (BP-ANN), and the numbers of principal components were calculated by the method of cross validation. The calculated principal components were used as the inputs of the artificial neural networks model, and the artificial neural networks model was used to find the relation between chlorophyll in winter wheat and reflective spectrum, which can predict the content of chlorophyll in winter wheat. The correlation coefficient (r) of calibration set was 0.9604, while the standard deviation (SD) and relative standard deviation (RSD) was 0.187 and 5.18% respectively. The correlation coefficient (r) of predicted set was 0.9600, and the standard deviation (SD) and relative standard deviation (RSD) was 0.145 and 4.21% respectively. It means that the MSC-ANN algorithm can reject noises in the original spectra produced by the environmental physical factor effectively and set up an exact model to predict the contents of chlorophyll in living leaves veraciously to replace the classical method and meet the needs of fast analysis of agricultural products.
Subject(s)
Chlorophyll/chemistry , Spectroscopy, Near-Infrared , Triticum/chemistry , Algorithms , Neural Networks, ComputerABSTRACT
Interaction modes of carbaryl and DNA were studied by resonance light scattering (RLS) spectra and absorption spectra. Experiments show that at pH 1.97, there are two interaction modes between carbaryl and ctDNA, namely surface assembly mode and intercalative mode. Interaction mode has a relation with the concentration ratio of carbaryl to ctDNA. Under this condition, the RLS intensity o f carbaryl and ctDNA is proportional to the concentration of ctDNA. According to this, one new simple and rapid method of determining ctDNA was set up. The linear ranges of the concentration of ctDNA were 0.02-3 microg x mL(-1), the linear regression equation was I = 200.77c (microg x mL(-1)) + 118.91, and the correlation coefficient was r = 0.998 9. This method has successfully been used to determine the synthetic samples.
Subject(s)
Carbaryl/analysis , DNA/analysis , Spectrum Analysis/methods , Animals , Carbaryl/chemistry , Cattle , DNA/chemistry , Hydrogen-Ion ConcentrationABSTRACT
The resonance light scattering (RLS) technique and UV-Vis absorption spectra were applied to the investigation of the interaction between atrazine and bovine serum albumin(BSA). Under acidic conditions, the formation of atrazine-BSA supermolecule by Van der Waals force and N/O--H...pi hydrogen bonds leads to a red shift of absorption band and strong RLS enhancement of atrazine. The characteristics and intensity of RLS were related to the pH, the concentration of atrazine, and temperature. Under the optimum conditions, the enhanced RLS intensities are in proportion to the concentration of BSA in the range of 0.05-100 microg x mL(-1). Based on the enhancement of the RLS, a simple and sensitive method for the determination of BSA was established. The detection limit (3sigma) is 12 ng x mL(-1). Synthesis samples were determined with satisfactory results.
Subject(s)
Atrazine/chemistry , Serum Albumin, Bovine/chemistry , Spectrometry, Fluorescence/methods , Spectrophotometry/methods , Animals , Cattle , Protein BindingABSTRACT
The calibration model for simultaneous determination of glucose, fructose and sucrose in aqueous solution was built by partial least squares and short-wavelength near infrared spectroscopy (800-1,100 nm). Twenty five samples in calibration set and 9 samples in prediction set were designed by orthogonal design. Building models from calibration set and validation for prediction set obtained the better results. For concentrations of glucose, fructose and sucrose in the ranges of 12.23-61.14 mg x mL(-1), 12.50-62.50 mg x mL(-1) and 12.09-60.44 mg x mL(-1), the relative standard deviations in the calibration set are 1.43%, 4.51% and 1.59% respectively, and the relative standard deviations in the prediction set are 3.40%, 3.73% and 2.80% respectively. The advantages of the method are simple and effective, with low cost for the simultaneous determination of multi-component system. It may be applied in practice easily.
ABSTRACT
The resonance light scattering (RLS) spectra of benzidine with deoxyribonucleic acid (ctDNA) in the presence of Sodium Dodecyl Sulfate had been studied. RLS intensity of SDS-benzidine system was enhanced by trace ctDNA and was proportional to the concentrationof ctDNA. Under optima conditions, the linear ranges of the calibration were 0.3-4 mg x L(-1), the linear regression equation was I = 37.17c (ctDNA, mg x L(-1)) + 208.9, r = 0.9992. The limit of detection were 0.17 mg x L(-1) (3delta), RSD% = 3.5%. The method had been applied to the determination of DNA in synthetic samples and gene tobacco sample, and the results were satisfactory.
Subject(s)
Benzidines/chemistry , DNA/analysis , Scattering, Radiation , Sodium Dodecyl Sulfate/chemistry , Spectrometry, Fluorescence/methods , Light , Limit of DetectionABSTRACT
The Resonance Light Scattering (RLS) spectra of atrazine with yeast ribonucleic acid (yRNA) had been studied. At pH 1.50, the enhanced RLS of atrazine-yRNA system is characterized by the maximum scattering peaks at 320 nm and the RLS intensity is proportional to the concentration of yRNA. Under optimal conditions, the linear ranges of the calibration were 0.6-5.0 microg x mL(-1), the linear regression equation was I = 25.88 + 140.0 c(yRNA, microg x mL(-1)), r = 0.9975, with the limit of detection 20.7 ng x mL(-1) (3delta). The method was applied to the determination of yRNA in synthetic samples and RNA in salt cress (Thellungiella halophila) sample satisfactorily. Mechanism studies show that there are two interaction modes between atrazine and RNA: electrostatic mode and intercalative mode.
