ANALYSIS of Soil Fourier Transform Infrared/Attenuated Total Reflection Spectral Data using Wavelet Analysis to Determine Soil Nitrate Content

2005 ◽  
Author(s):  
Bernie R. Jahn ◽  
Raphael Linker ◽  
Shrini K. Upadhyaya
Keyword(s):  
Fourier Transform ◽  
Wavelet Analysis ◽  
Spectral Data ◽  
Fourier Transform Infrared ◽  
Total Reflection ◽  
Attenuated Total Reflection ◽  
Nitrate Content ◽  
Soil Nitrate

scholarly journals Distinguishing active from quiescent disease in ANCA-associated vasculitis using attenuated total reflection Fourier-transform infrared spectroscopy

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Adam D. Morris ◽  
Camilo L. M. Morais ◽  
Kássio M. G. Lima ◽  
Daniel L. D. Freitas ◽  
Mark E. Brady ◽  
...  
Keyword(s):  
Fourier Transform ◽  
Unmet Need ◽  
Fourier Transform Infrared ◽  
Total Reflection ◽  
Attenuated Total Reflection ◽  
Remission Induction ◽  
Disease Remission ◽  
Anca Associated Vasculitis ◽  
Active Disease ◽  
Quiescent Disease

AbstractThe current lack of a reliable biomarker of disease activity in anti-neutrophil cytoplasmic autoantibody (ANCA) associated vasculitis poses a significant clinical unmet need when determining relapsing or persisting disease. In this study, we demonstrate for the first time that attenuated total reflection Fourier-transform infrared (ATR-FTIR) spectroscopy offers a novel and functional candidate biomarker, distinguishing active from quiescent disease with a high degree of accuracy. Paired blood and urine samples were collected within a single UK centre from patients with active disease, disease remission, disease controls and healthy controls. Three key biofluids were evaluated; plasma, serum and urine, with subsequent chemometric analysis and blind predictive model validation. Spectrochemical interrogation proved plasma to be the most conducive biofluid, with excellent separation between the two categories on PC2 direction (AUC 0.901) and 100% sensitivity (F-score 92.3%) for disease remission and 85.7% specificity (F-score 92.3%) for active disease on blind predictive modelling. This was independent of organ system involvement and current ANCA status, with similar findings observed on comparative analysis following successful remission-induction therapy (AUC > 0.9, 100% sensitivity for disease remission, F-score 75%). This promising technique is clinically translatable and warrants future larger study with longitudinal data, potentially aiding earlier intervention and individualisation of treatment.

Analysis of Captan on Nitrile Glove Surfaces Using a Portable Attenuated Total Reflection Fourier Transform Infrared Spectrometer

2005 ◽  
Vol 59 (6) ◽  
pp. 724-731 ◽  
Author(s):  
R. N. Phalen ◽  
Shane S. Que Hee
Keyword(s):  
Fourier Transform ◽  
Fourier Transform Infrared ◽  
Total Reflection ◽  
Attenuated Total Reflection ◽  
Surface Films ◽  
Airflow Rate ◽  
Infrared Spectrometer ◽  
Ftir Spectrometer ◽  
Selection Of ◽  
Solvent Volume

This study developed a method to produce uniform captan surface films on a disposable nitrile glove for quantitation with a portable attenuated total reflection Fourier transform infrared (ATR-FTIR) spectrometer. A permeation test was performed using aqueous captan formulation. Uniform captan surface films were produced using solvent casting with 2-propanol and a 25 mm filter holder connected to a vacuum manifold to control solvent evaporation. The coefficient of variation of the reflectance at 1735 ± 5 cm−1 was minimized by selection of the optimum solvent volume, airflow rate, and evaporation time. At room temperature, the lower to upper quantifiable limits were 0.31–20.7 μg/cm2 ( r = 0.9967; p ≤ 0.05) for the outer glove surface and 0.55–17.5 μg/cm2 ( r = 0.9409; p ≤ 0.05) for the inner surface. Relative humidity and temperature did not affect the uncoated gloves at the wavelength of captan analysis. Glove screening using ATR-FTIR was necessary as a control for between-glove variation. Captan permeation, after 8 hours exposure to an aqueous concentration of 217 mg/mL of Captan 50-WP, was detected at 0.8 ± 0.3 μg/cm2 on the inner glove surface. ATR-FTIR can detect captan permeation and can determine the protectiveness of this glove in the field.

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