Novel Lightpipes for Infrared Spectroscopy

1992 ◽  
Vol 46 (7) ◽  
pp. 1194-1197 ◽  
Author(s):  
S. J. Saggese ◽  
J. A. Harrington ◽  
G. H. Sigel ◽  
R. Altkorn ◽  
R. Haidle
Keyword(s):  
Infrared Spectroscopy ◽  
High Temperature ◽  
Low Cost ◽  
Infrared Transmission ◽  
Transmission Characteristics ◽  
Temperature Dependent ◽  
Low Loss ◽  
Mid Infrared ◽  
Temperature Performance ◽  
Ft Ir

The fabrication and temperature-dependent mid-infrared transmission characteristics of gold-on-nickel, silver-on-nickel, silica, and sapphire hollow lightpipes are discussed. The metal tubes offer improved low-temperature transmission and more versatile fabrication methods than do conventional FT-IR lightpipes. The dielectric tubes offer extremely low loss in certain spectral regions, outstanding high-temperature performance, and, in some cases, sufficiently low cost to be considered disposable.

scholarly journals New method for faecal fat determination by mid-infrared spectroscopy, using a transmission cell: an improvement in standardization

2000 ◽  
Vol 37 (3) ◽  
pp. 343-349 ◽  
Author(s):  
B S Jakobs ◽  
M Volmer ◽  
D W Swinkels ◽  
M T W Hofs ◽  
S Donkervoort ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Infrared Spectroscopy ◽  
Near Infrared ◽  
University Hospital ◽  
Infrared Transmission ◽  
Mid Infrared ◽  
Mid Infrared Spectroscopy ◽  
Faecal Samples ◽  
Significant Difference ◽  
Ft Ir

Current techniques used in clinical laboratories for faecal fat determination, such as the Van de Kamer method, are not very accurate or precise. This became apparent when results obtained by different laboratories were compared, and could explain the disappointing performance of near-infrared and mid-infrared spectroscopy since the accuracy of these techniques depends upon the accuracy of the calibration used (i.e. inaccurate wet chemical analysis). In order to improve standardization, we developed and tested a new quantitative method in three laboratories, based on Fourier transform infrared (FT-IR) spectroscopy. Fatty acids were extracted from faecal samples with acidified petroleum ether-ethanol and the extracts were dried and dissolved in chloroform. An infrared spectrum of the extracts was recorded in the range 4000-650 cmx1, using an infrared transmission cell. Standard mixtures of stearic and palmitic acids (65:35) were used for calibration. Quantification was based on the absorbance band of the CH 2 group (2855 cmx1) of free fatty acids and fatty acid glycerol esters. The calibration curve showed excellent linearity. The correlation coefficient between the titrimetric Van de Kamer and FT-IR methods was 0·96 ( y=1⋅12 x 0⋅02, standard error of prediction=0⋅89 g% fat). No significant difference was found when the FT-IR results of 28 faecal samples from patients were compared between two different university hospital laboratories. The new FT-IR method, using primary standards, is simple and rapid, and provides satisfactory intra- and inter-laboratory precision for the diagnosis and monitoring of steatorrhoea.

Milk acetone determination by the photometrical method after microdiffusion and via FT infra-red spectroscopy

2011 ◽  
Vol 28 (1) ◽  
pp. 33-48 ◽  
Author(s):  
Oto Hanuš ◽  
Václava Genčurová ◽  
Yunhai Zhang ◽  
Pavel Hering ◽  
Jaroslav Kopecký ◽  
...  
Keyword(s):  
Infrared Spectroscopy ◽  
Indirect Method ◽  
Geometric Mean ◽  
Mid Infrared ◽  
Subclinical Ketosis ◽  
Infra Red ◽  
Variation Range ◽  
Ft Ir ◽  
Infrared Method ◽  
Photometrical Method

Milk acetone determination by the photometrical method after microdiffusion and via FT infra-red spectroscopyMilk acetone (AC) and betahydroxybutyrate (BHB) are important indicators of the energy metabolism of cows (ketosis occurrence) and an effective method for their determination, with reliable results, is of great importance. The goal of this work was to investigate the infrared method MIR-FT in terms of its calibration for milk AC and to develop a usable procedure. The microdiffusion photometric (485 nm; Spekol 11) method was used with salicylaldehyde as a reference (Re) and mid infrared spectroscopy FT (MIR-FT: Lactoscope FT-IR, Delta; MilkoScan FT 6000, M-Sc) as an indirect method. The acetone addition to milk had no recovery using MIR-FT (Delta). The reference AC set must have acceptable statistics for good MIR-FT calibration (M-Sc) and they were: 10.1 ± 9.74 at a geometric mean of 7.26 mg l-1, and a variation range from 1.98 to 33.66 mg l-1. The AC correlation between Re and MIR-FT (Delta) was low at 0.32 (P>0.05 but the Log AC relationship between Re and MIR-FT (M-Sc) was markedly better at 0.80 (P<0.01). The conversion of >10 mg l-1 as an AC subclinical ketosis limit could be > -0.80 (feedback 0.158 mmol l-1 = 9.25 mg l-1) and > -1.66. This could be important for ketosis monitoring (using M-Sc).

scholarly journals Quantification and Classification of Diclofenac Sodium Content in Dispersed Commercially Available Tablets by Attenuated Total Reflection Infrared Spectroscopy and Multivariate Data Analysis

2021 ◽  
Vol 14 (5) ◽  
pp. 440
Author(s):  
Eirini Siozou ◽  
Vasilios Sakkas ◽  
Nikolaos Kourkoumelis
Keyword(s):  
Infrared Spectroscopy ◽  
Low Cost ◽  
Diclofenac Sodium ◽  
Reference Method ◽  
Sodium Content ◽  
Attenuated Total Reflection ◽  
Accuracy And Precision ◽  
Significant Difference ◽  
Ft Ir

A new methodology, based on Fourier transform infrared spectroscopy equipped with an attenuated total reflectance accessory (ATR FT-IR), was developed for the determination of diclofenac sodium (DS) in dispersed commercially available tablets using chemometric tools such as partial least squares (PLS) coupled with discriminant analysis (PLS-DA). The results of PLS-DA depicted a perfect classification of the tablets into three different groups based on their DS concentrations, while the developed model with PLS had a sufficiently low root mean square error (RMSE) for the prediction of the samples’ concentration (~5%) and therefore can be practically used for any tablet with an unknown concentration of DS. Comparison with ultraviolet/visible (UV/Vis) spectrophotometry as the reference method revealed no significant difference between the two methods. The proposed methodology exhibited satisfactory results in terms of both accuracy and precision while being rapid, simple and of low cost.

scholarly journals Study on Performance Damage and Mechanism Analysis of Asphalt under Action of Chloride Salt Erosion

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3089
Author(s):  
Peilei Zhou ◽  
Wensheng Wang ◽  
Lili Zhu ◽  
Haoyun Wang ◽  
Yongming Ai
Keyword(s):  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
High Temperature ◽  
Low Temperature ◽  
Temperature Sensitivity ◽  
Salt Solution ◽  
Solution Concentration ◽  
Chloride Salt ◽  
Temperature Performance ◽  
Low Temperature Performance

This study aims to investigate the performance evolution and mechanism of asphalt under action of chloride salt erosion. Asphalt samples soaked with five different snow melting chloride salt concentrations were taken as the research object. Then, the high-temperature performance, low-temperature performance, temperature sensitivity and asphalt–aggregate adhesion property of asphalt samples were carried out. Additionally, Fourier transform infrared spectroscopy (FTIR) was used to explore the mechanism of chloride salt erosion on asphalt. Test results showed the linear variation relationships of high-temperature performance, low-temperature performance and temperature sensitivity with chloride salt concentrations. The high-temperature performance of asphalt would be improved by chloride snowmelt salt. With the increase in the chloride salt solution concentration, the low-temperature performance of asphalt became worse, and the temperature sensitivity increased. Moreover, after the effect of the chloride salt solution, the asphalt–aggregate adhesion property decreased with the increase in the chloride salt solution concentration. It is necessary to control the amount of chloride snowmelt salt in the actual snow removal projects. Finally, based on Fourier transform infrared spectroscopy, the mechanism of chloride salt erosion on asphalt was preliminarily explored. With the increase in the chloride salt solution concentration, the proportion of light components (saturated fraction, aromatic fraction) in asphalt decreased, and the proportion of heavy components (resin and asphaltene) with good thermal stability increased.

Near- and Mid-Infrared Transmission Cells for the Study of Reverse Micelle Phases in Supercritical Fluids

1989 ◽  
Vol 43 (5) ◽  
pp. 812-816 ◽  
Author(s):  
J. P. Blitz ◽  
J. L. Fulton ◽  
R. D. Smith
Keyword(s):  
Ir Spectroscopy ◽  
Supercritical Fluids ◽  
Reverse Micelle ◽  
Infrared Range ◽  
Infrared Transmission ◽  
Mid Infrared ◽  
Elevated Pressures ◽  
Fluid Systems ◽  
Ft Ir ◽  
Ft Ir Spectroscopy

The design and construction of near- and mid-infrared transmission cells for the study of liquid, gaseous, and fluid systems at elevated pressures and temperatures are described. The cells can be used to pressures as high as 800 bar and temperatures exceeding 100°C. Typical spectra of reverse micelle phases in liquid propane and supercritical xenon through the near- and mid-infrared range are presented. The utility of applying FT-IR spectroscopy, and the transmission cells described here, to study reverse micelle and microemulsion phases in supercritical fluids is clearly demonstrated.

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