TATP and TNT detection by mid-infrared transmission spectroscopy

2009 ◽  
Author(s):  
Johannes Herbst ◽  
Jürgen Hildenbrand ◽  
Jürgen Wöllenstein ◽  
Armin Lambrecht
Keyword(s):  
Infrared Transmission ◽  
Mid Infrared ◽  
Transmission Spectroscopy ◽  
Tnt Detection

Mid-Infrared Transmission Spectroscopy of Sugar Solutions: Instrumentation and Analysis

1986 ◽  
Vol 19 (3) ◽  
pp. 277-291 ◽  
Author(s):  
Bernice L. Mills ◽  
E. C. Alyea ◽  
F. R. van de Voort
Keyword(s):  
Infrared Transmission ◽  
Mid Infrared ◽  
Transmission Spectroscopy

scholarly journals Proximate Analysis of Fish Tissue by Mid-Infrared Transmission Spectroscopy

1989 ◽  
Vol 46 (4) ◽  
pp. 644-649 ◽  
Author(s):  
G. S. Darwish ◽  
F. R. van de Voort ◽  
J. P. Smith
Keyword(s):  
Well Being ◽  
Fish Tissue ◽  
Proximate Analysis ◽  
Absolute Methanol ◽  
Compositional Variation ◽  
Milk Analysis ◽  
Infrared Transmission ◽  
Vacuum Oven ◽  
Mid Infrared ◽  
Transmission Spectroscopy

Mid-infrared spectroscopy was assessed as a means for rapidly determining the fat, protein, and moisture content of fish tissues. For fat and protein, a sample preparation protocol was developed for the conversion of fish tissue into a milk-like emulsion for analysis by a Multispec MK I infrared milk analyser. Fish (cod, tuna, and mackerel) were minced, dissolved, and emulsified in 0.2 M NaOH using a polytron and analysed for fat and protein using the conventional fat and protein wavelengths used for milk analysis. Instrument calibration for fat and protein was based on the Mojonnier and Kjeldahl procedures, respectively. Moisture was determined separately by extracting the water from the minced tissue using absolute methanol and measuring the absorbance of the resulting solution using a 5.56/6.02-μm filter pair. The instrument was calibrated using standardized water–methanol mixtures and the results compared with the standard vacuum oven method. Rapid analyses of fat and protein were possible giving individual results to within 1% of the standard chemical determinations. Moisture analysis, also worked well, being more accurate and rapid than the vacuum oven procedure. The limiting factor in its use for proximate analysis appears to be a combination of sample compositional variation and/or the general reproducibility of the standard methods. We conclude that the analysis of fish by mid-infrared transmission spectroscopy could serve as a means of rapidly carrying out the proximate analysis of fish and fish products for quality control purposes.

scholarly journals Estimation of composition of quinoa ( Chenopodium quinoa Willd.) grains by Near-Infrared Transmission spectroscopy

LWT ◽  
2017 ◽  
Vol 79 ◽  
pp. 126-134 ◽  
Author(s):  
Christian Encina-Zelada ◽  
Vasco Cadavez ◽  
Jorge Pereda ◽  
Luz Gómez-Pando ◽  
Bettit Salvá-Ruíz ◽  
...  
Keyword(s):  
Near Infrared ◽  
Chenopodium Quinoa ◽  
Infrared Transmission ◽  
Transmission Spectroscopy

Application of near Infrared Transmission Spectroscopy for the Determination of Some Quality Parameters of Apples

1994 ◽  
Vol 2 (4) ◽  
pp. 213-221 ◽  
Author(s):  
T. Lovász ◽  
P. Merész ◽  
A. Salgó
Keyword(s):  
Dry Matter ◽  
Near Infrared ◽  
Matter Content ◽  
Dry Matter Content ◽  
Quality Factors ◽  
Infrared Transmission ◽  
Transmission Method ◽  
Titratable Acid ◽  
Transmission Spectroscopy ◽  
Relative Standard

The acceptability of near infrared (NIR) transmission spectroscopy for the prediction of six quality factors of apples (firmness, refractive index, pH, titratable acid, dry matter and alcohol insoluble solids content) was investigated. The effects of storage conditions, cultivars and season on the accuracy of the NIR transmission method were also studied during the experiment. The accuracy of the calibration of all investigated parameters decreased during storage. The alteration of the characteristics of the spectra is possibly due to changes in the chemical composition and structure of apples between September and April. The calibration method was improved by developing a separate calibration for each cultivar per year. The calibrations of the different parameters are season-dependent except for the dry matter content. Using outlier diagnostics, the prediction accuracy can be generally improved by about 10%. The coefficient of variation for each parameter is compatible with the relative standard deviation for the reference methods except for the titratable acid content, showing the applicability of NIR transmission techniques. A relationship seems to exist between the maturity and the NIR transmission spectra of the apple.

Determination of Wavelength Accuracy in the Near-Infrared Spectral Region Based on NIST's Infrared Transmission Wavelength Standard SRM 1921

2000 ◽  
Vol 54 (3) ◽  
pp. 450-455 ◽  
Author(s):  
Stephen R. Lowry ◽  
Jim Hyatt ◽  
William J. McCarthy
Keyword(s):  
Reference Material ◽  
Standard Reference Material ◽  
Spectral Region ◽  
Near Infrared ◽  
Cost Effective ◽  
Infrared Transmission ◽  
Internal Reference ◽  
Mid Infrared ◽  
Infrared Spectral Region ◽  
Infrared Spectral

A major concern with the use of near-infrared (NIR) spectroscopy in many QA/QC laboratories is the need for a simple reliable method of verifying the wavelength accuracy of the instrument. This requirement is particularly important in near-infrared spectroscopy because of the heavy reliance on sophisticated statistical vector analysis techniques to extract the desired information from the spectra. These techniques require precise alignment of the data points between the vectors corresponding to the standard and sample spectra. The National Institute of Standards and Technology (NIST) offers a Standard Reference Material (SRM 1921) for the verification and calibration of mid-infrared spectrometers in the transmittance mode. This standard consists of a 38 μm-thick film of polystyrene plastic. While SRM 1921 works well as a mid-infrared standard, a thicker sample is required for use as a routine standard in the near-infrared spectral region. The general acceptance and proven reliability of polystyrene as a standard reference material make it a very good candidate for a cost-effective NIR standard that could be offered as an internal reference for every instrument. In this paper we discuss a number of the parameters in a Fourier transform (FT)-NIR instrument that can affect wavelength accuracy. We also report a number of experiments designed to determine the effects of resolution, sample position, and optics on the wavelength accuracy of the system. In almost all cases the spectral reproducibility was better than one wavenumber of the values extrapolated from the NIST reference material. This finding suggests that a thicker sample of polystyrene plastic that has been validated with the SRM 1921 standard would make a cost-effective reference material for verifying wavelength accuracy in a medium-resolution FT-NIR spectrometer.

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