bluuebunny/crossref_metadata_2025 huggingface dataset:
A General Test Method for the Development, Validation and Routine Use of Disposable near Infrared Spectroscopic Libraries
Authors: Tso Cindy , Ritchie Gary E. , Gehrlein Lane , Ciurczak Emil W.
Published: May 2009

We have developed a novel approach for using near infrared (NIR) spectroscopy; this is to create and apply calibration models “on-the-fly”. We define a process to create, validate, implement and approve a disposable library for discriminating between active and placebo pharmaceutical dosage forms packaged for clinical studies. This approach is based on two concepts; one germane to the particular needs and requirements of the pharmaceutical industry and the second based on an observation of the proposed experimental parameters. The first is that validation, in the general sense, implies control over a method. The second is that each clinical trial is a unique event, consisting of a finite or closed population of samples. The essence of the idea behind our process is to use disposable libraries, that is, libraries of NIR spectra created for one-time use and then archived. The justification for this approach is that the population of samples used both to create the library and subsequently to be identified using that library consists of a finite set of samples. This paper describes the rationale of this approach, discusses in detail the requirements for suitable protocols for using this method of verifying the dosages used in clinical trials, and describes the application of this approach on two separate clinical trials. Many other examples exist in the authors' laboratory. We also provide formatted templates that can be used to document and report NIR analytical results for discriminating between drug product and placebo dosage forms packaged in patient kits for clinical studies. The use of these templates, carefully designed to ensure regulatory requirements for validation are met, makes the implementation of the technique both rapid and compliant with regulatory requirements.
Prediction of Tenderness and other Quality Attributes of Beef by near Infrared Reflectance Spectroscopy between 750 and 1100 nm; Further Studies
Authors: Venel Caroline , Mullen Anne Maria , Downey Gerard , Troy D.J.
Published: May 2009

A study into prediction of selected organoleptic properties (tenderness, juiciness, flavour, texture, chewiness and acceptability) of beef at 14 days post mortem using NIR spectroscopy (750–1100 nm) was performed. M. longissimus dorsi and semimembranosus were studied from a total of 75 animals. NIR was unable to predict satisfactorily the selected organoleptic properties of semimembranosus. For M. longissimus dorsi, best results were obtained for the prediction of tenderness (Warner–Bratzler shear force; R = 0.51). Predictive performance was improved if the sample set was segregated according to animal grade, sex, ultimate pH or day of bone out post mortem ( R = 0.54–0.72).
Prediction and Classification of Tenderness in Beef from Non-Invasive Diode Array Detected NIR Spectra
Authors: Rødbotten Rune , Mevik Bjørn-Helge , Hildrum Kjell Ivar
Published: May 2009

NIR absorbance spectra of 48 beef samples were recorded 2, 9 and 21 days post mortem in the wavelength range 950–1700 nm with a Zeiss MCS 511 instrument equipped with diode array detector. These spectra were used to predict tenderness of the meat samples when Warner–Bratzler (WB) shear force was used as the reference method. Two types of prediction models were made. The models were either based on NIR spectra alone or NIR spectra in combination with information about post slaughter treatments. Prediction models from NIR spectra alone gave correlation coefficients in the range 0.52–0.83, but when variables for post slaughter treatments were included in the models the correlation coefficients were in the range 0.71–0.85. The additional variables had no effect on the prediction results when tenderness was predicted at the same time as NIR spectra were acquired, but improvements were found when tenderness was forecast later than the spectral acquisition. Based on these prediction models the beef samples were classified into two or three tenderness groups. When the beef samples were classified into two groups, 73–98% of the samples were correctly classified, while there were 63–75% correct classified samples when they were allocated into three groups.
Investigation of Starch–Protein–Water Mixtures Using Dynamic near Infrared Spectroscopy
Authors: Wesley I.J. , Blakeney A.B.
Published: May 2009

Dynamic near infrared (NIR) spectroscopy has been applied to the process of starch gelatinisation. A Rapid Visco-Analyser (RVA) was modified to allow NIR spectra to be recorded in real time as samples are heated and sheared. Analysis of the three-dimensional data obtained shows a major absorbance change at 1160 nm assigned to the stretch–bend combination mode of water and associated with the bonding of water molecules. There is also a major change in the 1400 nm region of the spectrum consisting of a combination of an absorbance change and a wavelength shift. The absorbance change at 1160 nm is shown to be associated with the gelatinisation of the starch granules, a process that occurs before pasting and gelation. The changes in the absorbance at 1160 nm also provide information on the interactions that occur when protein–starch–water mixtures are heated. The results obtained suggest that in excess water conditions, there is a complex interaction between gliadin, glutenin, starch and water which involves the initial ordering of water, increased ordering on stirring and the subsequent disordering of the water on heating, related to the presence of smaller protein molecules, occurring simultaneously with starch gelatinisation.
Near Infrared Spectroscopic Prediction of Physical Properties of Aromatics-Rich Hydrocarbon Mixtures
Authors: Reboucas Marcio V. , de Barros Neto Benicio
Published: May 2009

Near infrared spectroscopy multivariate calibration models were used to predict physical properties of aromatics-rich hydrocarbon mixtures obtained from Pyrolysis Gasoline units at the Copene petrochemical plant in Brazil. Relative density and distillation parameters (10%, 50%, 90% and 100% evaporated) were estimated from FT-NIR spectra in the 1670–1800 nm and 2100–2500 nm regions. Principal component analysis was used for exploratory data analysis and cross-validated one-block and two-block partial least-squares models were employed for calibration. Root Mean Square Errors of Prediction, based on six to nine PLS factors, were close to the measured repeatability values and the limits defined by ASTM methods: relative density = 0.0005, 10% evaporated = 0.489, 50% evaporated = 0.350, 90% evaporated = 0.579, 100% evaporated = 3.276. The present work has also demonstrated the ability of chemometric techniques to differentiate between spectra of quite similar aromatic compounds mainly due to the nature and location of substituent groups in the aromatic ring.
Improvement of PLS Calibration for Brix Value and Dry Matter of Mango Using Information from MLR Calibration
Authors: Saranwong Innapa , Sornsrivichai Jinda , Kawano Sumio
Published: May 2009

The possibility of using NIR spectroscopy for quality evaluation of intact mango was investigated using the short wavelength region from 700 nm to 1100 nm and the long wavelength region from 1100 nm to 2500 nm. Multiple linear regression (MLR) and partial least squares regression (PLS) were used to make the calibration equations for Brix value and dry matter (DM). The results obtained are as follows. (i) The short wavelength region was suitable for quality determination of intact mango because its penetration depth in mango flesh was higher than that of the long wavelength region. (ii) PLS calibration and validation results would be improved if the appropriate wavelength region was selected. (iii) The appropriate wavelength region for PLS regression could be estimated by using the wavelengths selected by MLR. (iv) The MLR and PLS calibration equations would have similar performance for determining Brix value and DM of intact mango if the appropriate wavelengths or wavelength region were selected.
Effect of Sample Presentation and Animal Muscle Species on the Analysis of Meat by near Infrared Reflectance Spectroscopy
Authors: Cozzolino D. , Murray I.
Published: May 2009

The useful wavelengths in both the visible and the near infrared region as well as two sample presentations (intact and minced) were evaluated to assess moisture (M), crude protein (CP) and intra muscular fat (IMF) in lamb ( n = 300), beef ( n = 100) and chicken ( n = 48) muscle samples. Samples were scanned in reflectance in a NIRSystems 6500 (NIRSystems, Silver Spring, MD, USA). Predictive equations were performed using modified partial least squares (MPLS) with internal cross-validation. The coefficient of determination in calibration ( R2CAL) and the standard error in cross-validation ( SECV) were calculated for each chemical parameter. For moisture, crude protein and fat (each expressed as g kg−1), R2CAL and SECV for beef muscle were 0.98, 0.81 and 0.96, respectively, and SECV was 33.1, 21.8 and 44.8 for beef muscle; for chicken muscle the comparable statistics were 0.99, 0.97 and 0.95 and SECV was 6.9, 2.4 and 33.1; while for lamb muscle R2CAL was 0.76, 0.83 and 0.73 and SECV 10.3, 5.5 and 4.7. It was concluded that the minced presentation is the best way to analyse muscle samples. On the other hand, intact presentation could have a great potential for use in the meat industry, although more research will be needed in order to determine quality attributes on meat samples.
Multivariate Classification of Sound and Insect-Infested Seeds of a Tropical Multipurpose Tree, Cordia Africana, with near Infrared Reflectance Spectroscopy
Authors: Tigabu Mulualem , Odén Per Christer
Published: May 2009

Near infrared (NIR) spectroscopy was used to classify insect-infested and sound seeds of a tropical multipurpose tree, Cordia africana Lam. A calibration model derived by partial least squares regression of orthogonal signal corrected spectra resulted in a 100% classification rate. Difference spectrum and partial least squares weight indicated that absorbance differences between insect-infested and sound seeds might have been due to differences in composition of chitin and cuticular lipid components as well as moisture content. The result shows the possibility of using NIR spectroscopy in the seed cleaning process in the future provided that appropriate sorting instruments are developed.
Measurement of the Concentrations of Mannosyl Erythritol Lipid and Soybean Oil in the Glycolipid Fermentation Process Using near Infrared Spectroscopy
Authors: Nakamichi Kazuhiro , Suehara Ken-Ichiro , Nakano Yasuhisa , Kakugawa Koji , Tamai Masahiro , Yano Takuo
Published: May 2009

In a glycolipid fermentation, mannosyl erythritol lipid (MEL) is produced from soybean oil added to a medium as a source of carbon. A measurement system for the concentrations of MEL and soybean oil in the fermentation process has been developed using near infrared (NIR) spectroscopy. MEL and soybean oil in the culture broth were extracted with ethyl acetate. NIR spectra of the ethyl acetate extract were measured in the wavelength range between 400 and 2500 nm at 2 nm intervals. The absorption caused by MEL was observed at 1436, 1920 and 2052 nm. To obtain a calibration equation, a multiple linear regression (MLR) was carried out between the second derivative NIR spectral data at 2040 and 1312 nm and MEL concentrations obtained using thin-layer chromatography with a flame-ionisation detector (TLC/FID) method. The values of the regression coefficient ( R) and the standard error of calibration ( SEC) were 0.994 and 0.48 g L−1, respectively. The absorption caused by soybean oil was observed at 1208, 1716, 1766, 2182 and 2302 nm. A calibration equation for soybean oil was formulated with the second derivative NIR spectral data at 2178 and 2090 nm. The values of R and SEC were 0.974 and 0.77 g L−1, respectively. After validation of the calibration equation, good agreement was observed between the results of the TLC/FID method and those of the NIR method for both constituents. The values of the correlation coefficient ( r) for MEL and the standard error of prediction ( SEP) were 0.994 and 0.45 g L−1, respectively. The values of r and SEP for soybean oil were 0.979 and 0.56 g L−1, respectively. The NIR method was applied to the measurement of the concentrations of MEL and soybean oil in an actual fermentation process and good results were obtained. The study indicates that NIR spectroscopy is a useful method for the measurement of the raw material and product in glycolipid fermentation.
Detection of Vegetable Proteins from Soy, Pea and Wheat Isolates in Milk Powder by near Infrared Spectroscopy
Authors: Maraboli Adele , Cattaneo Tiziana Maria Piera , Giangiacomo Roberto
Published: May 2009

This work aimed to prove the feasibility of using near infrared (NIR) spectroscopy to detect vegetable proteins (soy, pea and wheat isolates) in milk powder. One hundred and fifty-five samples of genuine and adulterated milk powder (NIZO, Ede, The Netherlands) were analysed by NIR spectroscopy using an InfraAlyzer 500 (Bran+Luebbe). NIR spectra were collected at room temperature, and data were processed by Sesame Software (Bran+Luebbe) to select the most significant wavelengths. Calibrations were made on all samples in the range 0–5% of added vegetable proteins. Separate prediction and validation sets were prepared using samples not included in the calibration set. The best results were obtained by applying multiple linear regression (MLR) to the first derivative of absorbance values at five wavelengths. NIR spectroscopy proved a very effective tool for detecting the presence of vegetable proteins in milk powder on the basis of standard error of calibration ( SEC), standard error of prediction ( SEP) and standard error of validation ( SEV) values found in this study. The calibration carve was characterised by a regression coefficient ( R2) equal to 0.993 with a SEC of 0.20, a SEP of 0.23 and a SEV of 0.21.
Using Fourier Transform near Infrared Spectroscopy in Determining Kernel Hardness, Protein and Moisture Content of Whole Wheat Flour
Authors: Manley M. , Van Zyl L. , Osborne B.G.
Published: May 2009

Fourier transform near infrared (FT-NIR) spectroscopy was used successfully to determine the kernel hardness, protein and moisture content of a single sample set of whole wheat flour. The hardness calibration was derived by performing partial least square (PLS) regression on baseline corrected data and using the particle size index (PSI) test as reference method. Both the protein and moisture calibrations were derived by performing PLS regression on multiplicative scatter corrected (MSC) and baseline corrected data. In all cases, the calibration models were subsequently tested by means of independent validation procedures. Good calibration and prediction results were obtained for all three characteristics. Standard error of prediction ( SEP), root mean standard error of prediction ( RMSEP) and correlation coefficient ( r) values of 2.13%, 4.53% and 0.42, respectively, were obtained for the hardness calibration. Corresponding results for the protein and moisture calibrations were 0.51%, 1.16%, 0.81 and 0.15%, 0.38% and 0.85, respectively. The FT-NIR protein and moisture results of this study compare satisfactorily with results achieved in previous FT-NIR studies. No other FT-NIR wheat hardness results have been reported elsewhere, but results of this study compare well to those achieved in other NIR wheat hardness studies.
Development of a Portable near Infrared Sugar-Measuring Instrument
Authors: Temma Tsuyoshi , Hanamatsu Kenkoh , Shinoki Fujitoshi
Published: May 2009

Industries from agriculture to petrochemistry have found near infrared (NIR) spectroscopic analysis useful for quality control and quantitative analysis of materials and products. The general chemical, polymer chemistry, petrochemistry, agriculture, food and textile industries are currently using NIR spectroscopic methods for analysis. In this study, we developed a portable NIR instrument for the non-destructive testing of products in the field, which has resulted in an instrument for commercial sale and use. The instrument consists of a light source, a polychromator, a wave-guide (optical fibre bundle) and a data processing unit. We tested the performance of the portable NIR instrument in determining the sugar content of apples. The performance was also examined at full width at half maximum ( FWHM) of the spectrum. The difference in the absorption of quartz and plastic fibres in the NIR was also compared. The sugar content measurements were confirmed by a high correlation to the Brix value of the apples, and the calibration showed the accuracy of the instrument in practice. Application of this instrument to fruits and vegetables other than apples was explored.
Usefulness of a Curve Fitting Method in the Analysis of Overlapping Overtones and Combinations of CH Stretching Modes
Authors: Katsumoto Yukiteru , Adachi Daisuke , Sato Harumi , Ozaki Yukihiro
Published: May 2009

This paper reports the usefulness of a curve fitting method in the analysis of NIR spectra. NIR spectra in the 7500–5500 cm−1 (1333–1818 nm) region were measured for water–methanol, water–ethanol and water–1-propanol mixtures with alcohol concentrations of 0–100 wt% at 25°C. The 6000–5600 cm−1 (1667–1786 nm) region, where the overtones and combinations of CH3 and CH2 stretching modes are expected to appear, shows significant band shifts with the increase in the alcohol content. To analyse the concentration-dependent spectral changes, a curve fitting method was utilised, and the results were compared with those obtained previously by a second derivative method. It was found that the first overtones of CH3 asymmetric and symmetric stretching modes of alcohols show a downward shift by about 15–30 cm−1 with the increase in the concentration of alcohols. The shifts are much larger for water–methanol mixtures than for water–ethanol and water–1-propanol mixtures. The first overtones and combinations of CH2 stretching modes of ethanol and 1-propanol also show a small downward shift. These shifts support our previous conclusion that there is an intermolecular “CH⃛O” interaction between the methyl group and water in the water–alcohol mixtures. The curve fitting method provided more feasible results for the band shifts than the second derivative method. It was revealed from the curve fitting method that the first overtone of the CH3 asymmetric stretching mode of water–methanol, water–ethanol and water–1-propanol mixtures shows different concentration-dependent plots. The first overtone of CH3 asymmetric stretching mode of water–methanol mixtures shifts more rapidly in the high methanol concentration range while that of water–1-propanol concentration shifts more markedly in the low 1-propanol concentration range. That of water–ethanol mixtures shows an intermediate trend. Based upon these differences structural differences among the three kinds of water–alcohol mixtures are discussed.
Spectroscopic Analysis of Dried Manures. Near- versus Mid-Infrared Diffuse Reflectance Spectroscopy for the Analysis of Dried Dairy Manures
Authors: Reeves James B. , Van Kessel Jo Ann S.
Published: May 2009

The objective was to examine and compare the ability of near- and mid-infrared diffuse reflectance spectroscopy to determine the composition of dried dairy manures. Samples ( n = 99) were dried at 60°C, ground and scanned in the near-infrared in a rotating sample cup on a Foss-NIRSystems model 6500 scanning monochromator, and in the mid-infrared on a Digilab FTS60 Fourier transform spectrometer using a custom-made sample transport device. While near-infrared calibrations for various measures of fibre composition (neutral detergent fibre etc.) were found to be possible, the results were generally less accurate than found for similar determinations in forages. Results based on mid-infrared spectra were sometimes better, and sometimes worse then near-infrared results, but again were not as accurate as found with forages. Overall, a clear advantage was not demonstrated for either region. Examination of the composition of the dried manures indicated that high ash contents (8–52% of dry matter) might be the cause for the decrease in calibration accuracy. However, a comparison of calibrations based on dry matter to those based on an ash-free basis showed no clear advantage for either means of computation. Accurate determination of minerals such as K or P was not possible using either spectral range (calibrations for K may be useful for gross segregation). In conclusion, while near- and mid-infrared calibrations appear feasible for determining the composition of dried dairy manures, better reference methods appear to be needed.
On-Line Monitoring of Rumen Fluid in Milking Cows by Fibre Optics in Transmittance Mode Using the Longer NIR Region
Authors: Turza Sándor , Chen Jie Yu , Terazawa Yoko , Takusari Naozumi , Amari Masahiro , Kawano Sumio
Published: May 2009

A simple near infrared (NIR) on-line transmittance measurement method for rumen fluid in cows was developed and tested with a specially-designed fibre optic probe. NIR spectra in the long wavelength region from 1100 to 1860 nm were used for analysing the chemical composition of rumen fluid in two selected cows. Partial least squares (PLS) calibrations were developed for the components considered to be important indicators of rumen fluid composition. The change in rumen fluid composition as a function of feeding was followed by spectral readings. The results indicate that NIR has the potential for on-line measurement of rumen fluid composition by using these specially-designed fibre optics.
A Preliminary Study on the Characterisation of Honey by near Infrared Spectroscopy
Authors: Davies Anthony M.C. , Radovic Branka , Fearn Tom , Anklam Elke
Published: May 2009

Near infrared (NIR) spectra were measured, at five temperatures, for 48 samples of honey, from a variety of geographical and botanical sources, and the data was used to explore the possibility of using NIR spectroscopy for testing label claims concerning the geographical and botanical source of honey being offered for sale to the public. Three spectra were obtained at each temperature and a blank spectrum was also recorded to check on the state of the system. Thus a total of 16 spectra were collected for each sample, and the complete experiment amounted to 768 spectra each containing 700 data points. These data were compressed by selection and principal component analysis so that they could be used in a canonical variates analysis (CVA) program. There were sufficient numbers of honeys from four botanical sources, acacia, chestnut, heather and rapeseed, to make use of CVA. Acacia and rapeseed formed clusters that were well separated from chestnut and heather clusters, which were partially overlapped. Mahalanobis distance ( MD) calculations were used to test group membership in a cross-validation experiment in which each of the 28 members of groups was left out of the calibration calculations, one at a time. When using 10 principal components (PCs) as the input variables, 19 of the honeys were assigned to the correct group while two honeys were incorrectly assigned to another group. When using 15 PCs, the number of correct assignments reduced to 13 but there were no incorrect assignments. There were 20 honeys which did not belong to the four test groups. When these were tested for group membership at 10 PCs, 10 were incorrectly assigned to a group. This reduced to two errors at 15 PCs. Tests on the country of origin were inconclusive. These results demonstrate that the successful characterisation of the botanical source of a honey may be obtained by NIR spectroscopy. Further work with larger numbers of samples and groups will be required to realise this potential.
Sucrose Content Determination of Sugar Beets by near Infrared Reflectance Spectroscopy. Comparison of Calibration Methods and Calibration Transfer
Authors: Roggo Y. , Duponchel L. , Noe B. , Huvenne J.-P.
Published: May 2009

The legal method (polarimetric measurement) for the determination of sucrose content since 1964 uses lead acetate. Because heavy metals are polluting, a law could forbid their use in the near future. Near infrared (NIR) spectroscopy is a suitable alternative method to replace it. For two years, 2412 samples of beet brei were analysed by NIR spectroscopy. In this article, spectral pre-processing and regression methods were compared in order to obtain an accurate prediction of sugar content. Analyse of variance and Fisher's tests were calculated to compare models (bias and Standard Error of Prediction corrected for bias) in terms of statistical significance. The model developed with spectra pre-treated by standard normal variate and second derivative gave the best results. The standard error of prediction of the ratio sucrose content/fresh beet weight was low (0.11 g / 100 g). The second part of this study shows that updating of the spectral database was possible. This makes it possible to take into account new variabilities of beet. For an industrial application, calibration transfer has to be studied. Sugar beet spectra or generic standard spectra were used on two NIR instruments. A simple linear regression wavelength by wavelength gives good results for the standardisation, demonstrating a possible use of the model on different instruments. In conclusion, the replacement of the polarimetric method by NIR spectroscopy was feasible.
Comparative in Vitro and Non-Invasive in Vivo Kromoscopic Measurements
Authors: Block Myron J. , Misner Michael W. , Guthermann Howard E.
Published: May 2009

Non-invasive optical assay of trace analytes in vivo is a great challenge. Kromoscopic analysis™, invented for this purpose, uses real time correlations between measurements that are both spatially and temporally congruent and made with multiple detection channels having overlapping spectral sensitivities. This method permits the segregation of effects of the cardiac pulse from effects occurring in the background. We report here on results obtained for a subset of detection spectral sensitivities proposed for non-invasive glucose measurements. For this set, two different mathematical forms of pulsatile measurement both indicate that the pattern of relative responses (Kolors) of different fingers used as measurement sites in different subjects is largely unaffected by differences among subjects or among measurement sites on the same subject. Furthermore, for both pulsatile and non-pulsatile measurements, changes in responses between in vitro and in vivo data are shown to be predictably caused by scattering.
Near Infrared Technology for Precision Environmental Measurements: Part 1. Determination of Nitrogen in Green- and Dry-Grass Tissue
Authors: McClure W.F. , Crowell B. , Stanfield D.L. , Mohapatra S. , Morimoto Susumu , Batten Graeme
Published: May 2009

The driving force for this work is rooted in data that confirms the contamination of streams and lakes caused from excessive use of nitrogen, pesticides and other soil amendments. Traditional analytical (wet chemistry) methods are too slow and too costly for detecting ecological abuse. A technology that would characterise the nutritional status of growing plants in a timelier manner (preferably in real time as an applicator moves through the field) is needed to control the volume of amendments. This paper explores the potential of near infrared (NIR) spectrometry for measuring nitrogen in plant tissue. In particular, it discusses the development of nitrogen calibrations, and performance of those calibrations, for both green- and dry-grass tissue. Results, based on collaborative studies by several researchers indicate that nitrogen can be measured with an SEP of 0.411% and 0.167% for green- and dry-grass tissue, respectively.
Visible and near Infrared Spectroscopy of Beef Longissimus Dorsi Muscle as a Means of Dicriminating between Pasture and Corn Silage Feeding Regimes
Authors: Cozzolino D. , Martins Vaz , Murray I.
Published: May 2009

Near infrared (NIR) reflectance spectroscopy was used as a tool to classify beef muscle samples according to their feeding regime. Seventy-eight beef longissimus dorsi muscle samples both intact and minced were scanned in a NIRS 6500 instrument (NIRSystems, MD, USA) in reflectance. A dummy regression technique was developed to differentiate beef muscle samples, which originated from beef feed exclusively on pasture or/and mainly on corn silage feeding regimes. Ninety percent of the pasture-fed beef muscle samples were correctly classified using principal component regression (PCR) and 86% of beef fed on corn silage were correctly classified. Both muscle chemical composition and physical characteristics explained the classification results. The results in the present study showed the potential of muscle optical properties for classification and traceability of meat muscles in the food chain.
On-Line Monitoring of Melt-Extrusion Transesterification of Ethylene Vinylacetate Copolymers by near Infrared Spectroscopy and Chemometrics
Authors: Furukawa Tsuyoshi , Kita Yasuo , Sasao Shigehiro , Matsukawa Kimihiro , Watari Masahiro , Šašic Slobodan , Siesler Heinz W. , Ozaki Yukihiro
Published: May 2009

The melt-extrusion transesterification of ethylene/vinylacetate (EVA) copolymer to ethylene/vinylalcohol (EVAL) copolymers has been monitored by on-line near infrared (NIR) spectroscopy. A total of 60 NIR spectra were measured within 37 minutes after the initial addition of octanol (reagent) and catalyst (sodium methoxide) at the exit of the extruder by use of a fibre-optic probe. The most significant intensity change is observed for a band at 7089 cm−1 due to the first overtone of an OH stretching mode of the EVAL copolymers. We can monitor the progress of the reaction by plotting the peak intensity at 7089 cm−1 only. A principal component analysis (PCA) was carried out for the series of NIR spectra in the 7300–6900 cm−1 region. A score plot of PCA factor 1 is almost identical with the plot of the peak intensity at 7089 cm−1. Calibration models for predicting the vinyl acetate content in EVA copolymers have been developed by use of partial least squares (PLS) regression. The correlation coefficient and standard error of prediction are 0.96 and 0.85%, respectively, indicating that the described technique can be used to monitor the transesterification reaction.
Rapid Determination of Heartwood Extractives in Larix sp. by Means of Fourier Transform near Infrared Spectroscopy
Authors: Gierlinger N. , Schwanninger M. , Hinterstoisser B. , Wimmer R.
Published: May 2009

The feasibility of Fourier transform near infrared (FT-NIR) spectroscopy to rapidly determine extractive and phenolic content in heartwood of larch trees ( Larix decidua MILL., L. leptolepis (LAMB.) CARR. and the hybrid L. x eurolepis) was investigated. FT-NIR spectra were collected from wood powder and solid wood using a fibre-optic probe. Partial Least Squares (PLS) regression analyses were carried out describing relationships between the data sets of wet laboratory chemical data and the FT-NIR spectra. Besides cross and test set validation the established models were subjected to a further evaluation step by means of additional wood samples with unknown extractive content. Extractive and phenol contents of these additional samples were predicted and outliers detected through Mahalanobis distance calculations. Models based on the whole spectral range and without data pre-processing performed well in cross-validation and test set validation, but failed in the evaluation test, which is based on spectral outlier detection. But selection of data pre-processing methods and manual as well as automatic restriction of wavenumber ranges considerably improved the model predictability. High coefficients of determination ( R2) and low root mean square errors of cross-validation ( RMSECV) were obtained for hot water extractives ( R2 = 0.96, RMSECV = 0.86%, range = 4.9–20.4%), acetone extractives ( R2 = 0.86, RMSECV = 0.32%, range = 0.8–3.6%) and phenolic substances ( R2 = 0.98, RMSECV = 0.21%, range = 0.7–4.9%) from wood powder. The models derived from wood powder spectra were more precise than those obtained from solid wood strips. Overall, NIR spectroscopy has proven to be an easy to facilitate, reliable, accurate and fast method for non-destructive wood extractive determination.
Application of near Infrared Reflectance Spectroscopy for the Analysis of Organic C, Total N and pH in Soils of Uruguay
Authors: Morón A. , Cozzolino D.
Published: May 2009

Near infrared (NIR) reflectance spectroscopy was used to analyse samples ( n = 332) from different soils from Uruguay (South America) for organic carbon (OC), total nitrogen (N) and pH. One set ( n = 200) of samples randomly selected was used to develop the NIR calibrations while the remaining ( n = 132) samples were used as the validation set. The samples were scanned in a small circular cup in reflectance mode (400–2500 nm), using a Foss NIRSystems 6500 (Silver Spring, MD, USA). Modified partial least squares (MPLS) was used to produce the calibration models and cross-validation was used to avoid collinearity effects among variables. Three mathematical treatments and four scatter corrections were also applied. The calibration coefficient of determination ( R2CAL) and the standard error in cross-validation ( SECV) were 0.94 ( SECV: 1.9) for OC; 0.91 ( SECV: 0.19) for total N in g kg−1 and 0.93 ( SECV: 0.18) for pH, respectively. The simple correlation coefficient of validation ( rVAL) and the standard errors of prediction ( SEP) were 0.74 and 5; 0.73 and 0.4; 0.84 and 0.28 for OC, total N and pH, respectively.
Solid Dosage Form Analysis by near Infrared Spectroscopy: Comparison of Reflectance and Transmittance Measurements Including the Determination of Effective Sample Mass
Authors: Iyer Meenakshy , Morris Hannah R. , Drennen James K.
Published: May 2009

Investigations into the near infrared analysis of intact tablets allow comparison of the reflectance and transmittance methodologies. The studies involved estimation of the effective sample mass and the effect of sample inhomogeneities. An empirical method for determining effective sample mass used tablets of varying thickness and constant compression force. Tablets containing a range of cimetidine concentrations were used to study the effect of drug concentration on effective sample mass as a function of wavelength of observation. Effective sampling depth was between 1.9 and 2.7 mm for reflectance measurements. With transmittance measurements, signal was completely attenuated when tablet thickness was greater than 3.4–4.9 mm, depending on the wavelength of observation. Multi-layered tablets provided a means of probing the effect of sample inhomogeneity. Both reflectance and transmittance measurements may be sensitive to sample inhomogeneity. Transmittance measurements are sensitive to pathlength variations.
Evaluation of Standardisation Methods of near Infrared Calibration Models
Authors: Lima F.S.G. , Borges L.E.P.
Published: May 2009

The standardisation of eight partial least squares calibration models for the prediction of diesel oil properties was studied. The models were developed using spectra acquired on a laboratory accousto-optic tunable filter (AOTF) near infrared (NIR) spectrophotometer (with a quartz cuvette) and transferred to another AOTF-NIR spectrophotometer (with a fibre-optic probe) and to an Fourier transform NIR spectrometer, both designed for on-line application. Thirteen standardisation methods, using different approaches, were studied: standardisation by the pretreatment of spectra, (piecewise) direct standardisation and (piecewise) reverse standardisation. The reverse approach proved to be the best strategy to transfer the models.
Detection and Quantification of Apple Adulteration in Strawberry and Raspberry Purées Using Visible and near Infrared Spectroscopy
Authors: Contal Laure , León Vanessa , Downey Gerard
Published: May 2009

Adulteration of strawberry and raspberry purées with apple is a potential authenticity issue. In purée form, detection of such adulteration is not easy. A series of pure strawberry ( n = 32) and raspberry ( n = 32) purées was prepared. Strawberry and raspberry samples were adulterated at levels of 10, 20, 30, 50 and 75% (w/w) apple using different ( n = 28) apple samples. Reflectance spectra were recorded using two different sample cell types. Classification of pure and adulterated fruit samples was investigated using soft independent modelling of class analogy. Best models permitted detection of apple adulteration at levels of > 20% w/w (strawberry) and > 10 < 20% w/w (raspberry). Quantification of adulterant content was by partial least squares regression. The most accurate models produced prediction errors of 3.4% apple (in raspberry) and 5.5% apple (in strawberry).
Effect of Multiplicative Scatter Correction on Wavelength Selection for near Infrared Calibration to Determine Fat Content in Raw Milk
Authors: Chen Jie Yu , Iyo Chie , Terada Fuminori , Kawano Sumio
Published: May 2009

The effect of multiplicative scatter correction (MSC) on wavelength selection for near infrared (NIR) calibration to determine fat content in raw milk was investigated. Short-wave NIR spectra (700–1100 nm) of raw milk samples were measured. The calibration equations for fat content were performed by multiple linear regression (MLR) using original, second derivative and MSC-treated spectra. It was found that first wavelength selection from the fat absorption band for a calibration equation was generally effective in all cases of original, second derivative and MSC-treated spectra. However, correlation plots did not always work well because of the multiplicative scatter effect presented in the samples. Whereas, correlation plots were still useful in the case of MSC-treated spectra and normalised second derivative spectra, even when the original spectra exhibited a multiplicative scatter effect.
Use of near Infrared Reflectance Spectroscopy to Analyse Bovine Faecal Samples
Authors: Cozzolino D. , La Manna A. , Martins D. Vaz
Published: May 2009

Near infrared (NIR) reflectance spectroscopy was used to predict nitrogen (N), acid detergent fibre (ADF), neutral detergent fibre (NDF) and chromium (Cr) in beef faecal samples. One hundred and twenty faecal samples were scanned in a NIRSystems 6500 monochromator instrument over the wavelength range of 400–2500 nm in reflectance. Calibration equations were developed using modified partial least squares (MPLS) with internal cross validation to avoid overfitting. The coefficient of determination in calibration ( R2cal) and the standard error in cross validation ( SECV) were 0.80 (0.74) for N, 0.92 (12.04) for ADF, 0.86 (13.5) for NDF and 0.56 (0.07) for Cr in g kg−1 dry weight, respectively. Results for validation were 0.78 ( SEP: 0.1) for N, 0.74 ( SEP: 7.5) for ADF, 0.85 ( SEP: 8.5) for NDF and 0.10 (0.09) for Cr in g kg−1 dry weight, respectively.
Changes in Moisture Content during Wheat Maturation—What is Measured by near Infrared Spectroscopy?
Authors: Gergely Szilveszter , Salgó András
Published: May 2009

The aim of the present study was to detect maturation processes in wheat seed non-destructively with special respect to changes in moisture content and natural hydration/dehydration processes. Maturation is a phase of seed development in which a series of biochemical, enzymatic and morphological changes occur under highly hydrated conditions. The role of water is therefore critical to the whole maturation process. The amount and variation in content of different water species [high density water (HDW) with weaker hydrogen bonding and low density water (LDW) with stronger hydrogen bonding] changed considerably during maturation. Characteristic changes in three water absorption bands [1890–1920 nm (water I), 1400–1420 nm (water II) and 1150–1165 nm (water III)] were analysed. It was concluded that the different transitions of water molecules could be followed sensitively through different regions of NIR spectra. In the maturing seed, combination bands (water I and water III) were more sensitive indicators of changes in water molecules than was the first overtone (water II). The polar qualification system (PQS) provided sensitive and informative results regarding the amount and species of water in the developing seed. NIR spectroscopic techniques can be used effectively in monitoring plant physiological processes and the spectra have hidden information for predicting the stage of growth in wheat seed.
Investigation on Deep Layer Measurements in the Cerebral Cortex within the Adult Head by near Infrared Spectroscopy Using an Absorbance Difference Technique
Authors: Ohnishi Michihiro , Kusakawa Naoki , Masaki Shinobu , Honda Kiyoshi , Shimada Yasuhiro , Fujimoto Ichiro , Hirao Konomu
Published: May 2009

Recent reports on modeled simulation of near infrared photons' paths in the adult head have shown that the cerebrospinal fluid functions as an optical guide, suggesting that non-invasive haemodynamic measurement of the deep layer of the cerebral cortex is difficult. Thus, the authors investigated the volume of the cortex measured by near infrared spectroscopy with the absorbance difference technique. This technique uses two radiation detector probes to yield short and long photon paths in order to realise selective measurement of the cortex by minimising the interference from the superficial layers covering the cortex. The results show that the volume of the cortex measured by this technique is larger in the temporal area than in the frontal area. Therefore, it is concluded that the photons' path in the temporal area reaches the deep layer of the cortex and that it is possible to measure the haemodynamic response of the auditory cortex in the deep temporal area of the adult head to sound stimuli.
The Application of Localisation to near Infrared Calibration and Prediction through Partial Least Squares Regression
Authors: Anderssen R.S. , Osborne B.G. , Wesley I.J.
Published: May 2009

Near infrared (NIR) calibration and prediction represents a strategy for solving the inverse problem of determining the input sample property from its output NIR spectrum. The spectrum is an indirect measurement of the property that has been smoothed, leading to a loss of information. As a result, small changes in the spectra can, on occasions, correspond to large changes in the property. However, the well-established mathematical theory of regularisation has been developed for the solution of indirect measurement and inverse problems. Regularisation seeks an approximation to the input that simultaneously forces the model output to agree closely with the observed output and guarantees that appropriate constraints about the behaviour of the input are satisfied. In partial least squares regression, this is achieved through the simultaneous fitting of a model to the measured spectra and another to the property data, with the models coupled through the same set of regression factors. It is this idea that must be carried over to localisation in order to transform it into a stabilised algorithm. In other words, localisation should be carried out with respect to both the spectrum and the property. This paper presents a theoretical basis for this concept together with the results of simulation experiments that compares the effects of localisation with respect to both the spectra and the property with spectrum only and property only localisation.
Determination of Hydrogen Peroxide by near Infrared Spectroscopy
Authors: Pimenta Adriana M. , Scafi Sérgio H. Frasson , Pasquini Celio , Raimundo Ivo M. , Rohwedder Jarbas J.R. , Montenegro Maria da Conceição B.S.M. , Araújo Alberto N.
Published: May 2009

Near infrared (NIR) spectroscopy has been employed for the determination of hydrogen peroxide in antiseptic pharmaceutical preparations where it is found in concentrations of about 3.0% (w/v). Standard solutions containing hydrogen peroxide in the range 0–10% (w/v) were prepared and split into two groups, which were used for partial least squares (PLS1) modelling and for initial evaluation of the model performance. Absorbance spectra, in the wavelength range from 850 to 1800 nm, were obtained using a transflectance probe with optical path of 1.0 mm. The first derivative of the absorption spectra were employed for PLS1 modelling, which requires two factors, resulting in a root mean square error of cross-validation of 0.07% obtained by full cross-validation. The model was evaluated by using prepared and commercial samples of pharmaceuticals containing H2O2 in the range from 1 to 20% resulting in a root mean standard error of prediction of 0.05%.
A Comparison of Techniques for Modelling Data with Non-Linear Structure
Authors: Stordrange Laila , Kvalheim Olav M. , Hassel Per A. , Malthe-Sørenssen Dick , Libnau Fred Olav
Published: May 2009

Partial least squares (PLS) is a powerful tool for multivariate linear regression. But what if the data show a non-linear structure? Near infrared spectra from a pharmaceutical process were used as a case study. An ANOVA test revealed that the data are well described by a 2nd order polynomial. This work investigates the application of regression techniques that account for slightly non-linear data. The regression techniques investigated are: linearising data by applying transformations, local PLS, i.e. splitting of data, and quadratic PLS. These models were compared with ordinary PLS and principal component regression (PCR). The predictive ability of the models was tested on an independent data set acquired a year later. Using the knowledge of non-linear pattern and important spectral regions, simpler models with better predictive ability can be obtained.
On-Line Classification of Synthetic Polymers Using near Infrared Spectral Imaging
Authors: Kulcke A. , Gurschler C. , Spöck G. , Leitner R. , Kraft M.
Published: May 2009

The lack of industrially-applicable, fast polymer classification systems is currently a major stumbling block in establishing both economically- and ecologically-useful waste recycling systems. With the advent of near infrared (NIR) spectral imaging for online classification, a method capable of distinguishing between different materials while simultaneously providing reliable size and shape information became available. In particular, polymer materials can be identified by their characteristic reflection spectra in the NIR without critical interferences from varying sample sizes and colours. A dedicated laboratory-scale prototype spectral imaging system has been developed and a number of classification algorithms have been evaluated for their applicability for polymer classification. Of the investigated algorithms, the Spectral Angle Mapper algorithm, supplemented by a threshold value and applied to the first derivatives of the normalised spectra, proved to be best suited for a rapid and reliable classification of polymers. Based on these achievements, an on-line system capable of classifying polymer parts delivered on a conveyor belt in real-time has been set up, which can be used, for example, as a sensor for fully-automated industrial polymer waste sorters.