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 ◽  
...  

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).

1992 ◽  
Vol 46 (7) ◽  
pp. 1194-1197 ◽  
Author(s):  
S. J. Saggese ◽  
J. A. Harrington ◽  
G. H. Sigel ◽  
R. Altkorn ◽  
R. Haidle

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.


Author(s):  
B S Jakobs ◽  
M Volmer ◽  
D W Swinkels ◽  
M T W Hofs ◽  
S Donkervoort ◽  
...  

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.


2021 ◽  
Vol 164 ◽  
pp. 106029
Author(s):  
Diego Maciel Gerônimo ◽  
Sheila Catarina de Oliveira ◽  
Frederico Luis Felipe Soares ◽  
Patricio Peralta-Zamora ◽  
Noemi Nagata

Author(s):  
Erdoğan Karip ◽  
Mehtap Muratoğlu

People are exposed to different kinds of diseases or various accidents in life. Hydroxyapatite (HA) has been widely employed for bone treatment applications. In this study, HA was extracted from sheep bones. Bio-composites were doped with 1, 5, and 10 wt.% of expanded perlite and 5 wt.% of ZrO2–MgO-P2O5. The bio-composites were prepared by the cold isostatic pressing method (250 MPa) and sintered at 900°C for 1 h. In order to evaluate the characteristics of the bio-composites, microhardness, density, X-ray diffraction (XRD), Fourier transform infra-red spectroscopy (FT-IR), scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS) analyses were carried out on them. Additionally, the specimens whose characteristics were determined were kept in synthetic body fluid (SBF), and their in vitro behavior was examined. As a result, it was observed that microhardness increased as both the weight and the grain size of the expanded perlite were increased. Calcium silicate, tri-calcium phosphate, and hydroxyapatite were observed in the XRD analysis of all samples, and the formation of apatite structures was increased by addition of ZrO2–MgO–P2O5.


2021 ◽  
Vol 14 (5) ◽  
pp. 440
Author(s):  
Eirini Siozou ◽  
Vasilios Sakkas ◽  
Nikolaos Kourkoumelis

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.


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