Near infrared spectroscopy, a diverse analytical tool with unlimited potential for discoveries! (original) (raw)

n Data treatment in near infrared spectroscopy

2016

m e a s u rements of liquids can be done using standard s cuvettes and, reflectance measurements of powders can be realised using fiber optics. NIR spectro s c o py is thus a method that re q u i re few or no sample prep a rat i o n. Absorption bands observed in NIR spectra are due to over-tones of, mainly, hydrogenic stretching vibrations or combi-nation involving stretching and bending modes of vibration. Those bands are thus broader than in middle infrared and spectra are considerably more complex. Due to this com-p l ex i t y, NIR spectro s c o py has soon taken adva n t age of sophisticated calibration techniques and is now using state of the art data treatment. This article will illustrate, first the spectral transformation and then the two current uses of NIR spectroscopy: quali-tative discriminant analysis and quantitative applications.

NIR spectroscopy: a rapid-response analytical tool

In recent years, near-infrared (NIR) spectroscopy has gained wide acceptance in different fields by virtue of its advantages over other analytical techniques, the most salient of which is its ability to record spectra for solid and liquid samples with no prior manipulation. Also, developments in instrumentation have resulted in the manufacture of spectrophotometers capable of quickly providing spectra that are flexible enough for use in different situations; thus, portable equipment can record spectra on site or even at production lines. This article discusses the features of NIR spectroscopy that have driven forward its dramatic development in a wide range of analytical fields in the last few years. #

Influence of Sample Temperature for Measurement Accuracy with FT-NIR Spectroscopy

Journal of AOAC International, 2017

This study monitored the influence of milk samples temperature on the measuring accuracy of FT-NIR spectroscopy in milk content analysis. Reference methods were used to determine dry matter, fat, protein, and lactose content in cow's milk. Milk samples were measured in reflectance mode on an integrating sphere with the use ofa compression cuvette and a transflectance cuvette, ensuring a beam trajectory length of h = 0.2 mm. The samples were measured at 18, 20, 22, 24, and 40°C, and analyses were performed at 100 scansat a resolution of 8 cm−1. The measurements were influenced by the temperatures of the samples during the evaluation of all analyzed constituents (P < 0.05). Our results confirmed that the accurate determination of milk constituents requires maintaining, during analysis, the temperature conditions of the samples and the conditions for which the spectrophotometer calibration was designed.

149 - 2000 - Trans determination of edible oils by Fourier transform near-infrared spectroscopy.

JAOCS 77 (10) 1061-1067.

A generalized partial-least-squares calibration for determination of the trans content of edible fats and oils by Fourier transform near-infrared (FT-NIR) spectroscopy using 8-mm disposable glass vials for sample handling and measurement was developed. The trans contents of a broad range of oils were determined using the American Oil Chemists' Society single-bounce horizontal attenuated total reflectance (SB-HATR) mid-infrared spectroscopic procedure, these trans reference data were used in the development of the generalized FT-NIR calibration. Additional refined and product-specific calibrations were also developed, and all the calibrations were assessed for their predictive capabilities using two sets of validation samples, one comprising a broad range of oil types and the other restricted to oils with specific characteristics. The FT-NIR trans predictions obtained using the generalized calibration were in good agreement with the SB-HATR results; the values were accurate and reproducible to within ±1.1 and ±0.5% trans, respectively, compared to a reproducibility of ±0.40% trans obtained for the SB-HATR method. The accuracy of the predictions obtained from the generalized FT-NIR calibration for particular oil types was not significantly improved by supplementing the base training set with samples of these specific types. Calibrating only these oil types did, however, produce a substantial improvement in predictive accuracy, approaching that of the SB-HATR method. These product specific calibrations produced serious predictive errors when nonrepresentative samples were analyzed. The incorporation of a supplementary discriminate analysis routine was found to be a powerful safeguard in flagging nonrepresentative samples as outliers and could also be used to select the calibration most appropriate for the characteristics of the sample being analyzed. Overall, it was concluded that FT-NIR spectroscopy provides a viable alternative to the SB-HATR/mid-Fourier transform infrared method for trans determination, making use of more industrially robust instrumentation and equipped with a simpler sample handling system.

NIR Spectroscopy and Its Applications

—Near-infrared Spectroscopy (NIRS) is a spectroscopic method that uses the near infrared region of the electromagnetic spectrum (from about 800 nm to 2500 nm). Typical applications include pharmaceutical, medical diagnostics (including blood sugar and oximetery),food and agrochemical quality control, as well combustion research.

NIR SPECTROSCOPY: TECHNOLOGY READY FOR FOOD INDUSTRIES APPLICATIONS

Recently, NIR spectroscopy has gained wide acceptance in different fields like drug and pharmaceutics, petroleums and food industries. NIR technology is going to bethe substitute technology over conventional chemical test methods due to advancements in instrumentation technology, availability of open source tools, and developments in photonics components. The ability of the spectrophotometers to record spectra in almost no time makes this technology most suitable for online analysis. Genetically Modified Organism (GMO) being the most serious concern these days can be addressed and dealt with using NIR spectroscopy. This article focuses on the potential capabilities of this technology in food industries

Near-Infrared Spectroscopy as a Process Analytical Tool Part I: Laboratory Applications

Spectroscopy

ear-infrared (NIR) spectroscopy has been used for qualita-tive and quantitative measurements in the agricul-tural, food, and chemical indus-tries for several decades. It has also been effectively used in nu-merous pharmaceutical applica-tions, from the inspection of in-coming raw materials to the final testing of manufactured products. Improving product quality and lowering cost are drivers in decision making for many in-dustries. Ensuring product quality throughout the manu-facturing process can be time-consuming, with materials and product quarantined until test results are generated. Rapid testing by NIR spectroscopy, at all stages of the manufactur-ing process, can reduce manu-facturing time and provide