scholarly journals Stoichiometric Determination of Hydroperoxides in Oils by Fourier Transform Near-Infrared Spectroscopy

1997 ◽  
Vol 80 (2) ◽  
pp. 345-352 ◽  
Author(s):  
Jun Dong ◽  
Ma Kangming ◽  
Frederick R Van De Voort ◽  
Ashraf A Ismail
Keyword(s):  
Fourier Transform ◽  
Standard Deviation ◽  
Near Infrared ◽  
Edible Oils ◽  
Spectroscopic Method ◽  
Calibration Model ◽  
Aocs Method ◽  
Analytical Technique ◽  
Stoichiometric Reaction

Abstract A rapid Fourier transform near-infrared (FT-NIR) spectroscopic method was developed for quantitative determination of the peroxide values (PVs) of edible oils. The method is based on the stoichiometric reaction of triphenylphosphine (TPP) with hydroperoxides to produce triphenylphosphine oxide (TPPO). Calibration standards were prepared by adding randomized amounts of TPPO and TPP to peroxide-free high-erucic-acid rapeseed (HEAR) to produce a calibration matrix spanning the concentrations of TPPO and residual TPP in oils having PVs in the range 0-100 after complete reaction of the hydroperoxides with added TPP. A partial-least-squares (PLS) calibration model for predicting PV was developed by using the NIR spectral region from 4710 to 4540 cm-1, where TPP and TPPO both absorb. The resulting PLS calibration was linear, the cross-validation having a standard deviation (SD) of 1.36 PV over the analytical range. The method was validated by comparing the PLS-predicted PVs of oils spiked with tert-butyl hydroperoxide (TBHP) and those of naturally oxidized HEAR oils with the results obtained by using the American Oil Chemists’ Society (AOCS) iodometric procedure. The FT-NIR PV method correlated very well (SD = 1.20) with the reference AOCS method for TBHP-spiked oil samples. Similar results were obtained for naturally oxidized HEAR oil, with a standard deviation of the difference for reproducibility of ±1.11 PV for both methods. The analysis consists of adding about 0.04 mL TPP stock solution to 1 g oil, shaking, recording the spectrum, and using the PLS calibration to predict PV. Because of its simple and rapid stoichiometric reaction and its excellent correspondence to the iodometric method, the FT-NIR method provides a simple and alternative means of measuring PV. The FT-NIR method avoids the solvent and reagent disposal problems associated with the AOCS method and can be readily auto mated by appropriate programming of the FTIR spectrometer. Thus, it provides a simple and rapid analytical technique for determining PVs of fats and oils.

scholarly journals Monitoring of CO2 Absorption Solvent in Natural Gas Process Using Fourier Transform Near-Infrared Spectrometry

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Mohd Yusop Nurida ◽  
Dolmat Norfadilah ◽  
Mohd Rozaiddin Siti Aishah ◽  
Chan Zhe Phak ◽  
Syafiqa M. Saleh
Keyword(s):  
Fourier Transform ◽  
Near Infrared ◽  
Nir Spectroscopy ◽  
Partial Least Square ◽  
Least Square ◽  
Infrared Spectrometry ◽  
Calibration Model ◽  
Co2 Absorption ◽  
Processing Unit

The analytical methods for the determination of the amine solvent properties do not provide input data for real-time process control and optimization and are labor-intensive, time-consuming, and impractical for studies of dynamic changes in a process. In this study, the potential of nondestructive determination of amine concentration, CO2 loading, and water content in CO2 absorption solvent in the gas processing unit was investigated through Fourier transform near-infrared (FT-NIR) spectroscopy that has the ability to readily carry out multicomponent analysis in association with multivariate analysis methods. The FT-NIR spectra for the solvent were captured and interpreted by using suitable spectra wavenumber regions through multivariate statistical techniques such as partial least square (PLS). The calibration model developed for amine determination had the highest coefficient of determination (R2) of 0.9955 and RMSECV of 0.75%. CO2 calibration model achieved R2 of 0.9902 with RMSECV of 0.25% whereas the water calibration model had R2 of 0.9915 with RMSECV of 1.02%. The statistical evaluation of the validation samples also confirmed that the difference between the actual value and the predicted value from the calibration model was not significantly different and acceptable. Therefore, the amine, CO2, and water models have given a satisfactory result for the concentration determination using the FT-NIR technique. The results of this study indicated that FT-NIR spectroscopy with chemometrics and multivariate technique can be used for the CO2 solvent monitoring to replace the time-consuming and labor-intensive conventional methods.

scholarly journals Improved Determination of Isolated trans Isomers in Edible Oils by Fourier Transform Infrared Spectroscopy Using Spectral Reconstitution

2007 ◽  
Vol 90 (2) ◽  
pp. 446-451 ◽  
Author(s):  
Frederik R van de Voort ◽  
Jacqueline Sedman ◽  
Syed Tufail Hussain Sherazi
Keyword(s):  
Fourier Transform ◽  
Edible Oils ◽  
Spectroscopic Method ◽  
Virgin Olive Oil ◽  
Fourier Transform Infrared ◽  
Extra Virgin Olive Oil ◽  
Trans Content ◽  
Trans Isomers ◽  
Mineral Spirits

Abstract A substantially more sensitive and accurate alternative to the single-bounce attenuated total reflectance (SB-ATR) Fourier transform infrared spectroscopic method of AOAC/American Oil Chemists' Society (AOCS) was developed for determination of isolated trans isomers, based on transmission measurements using a technique called spectral reconstitution (SR). The method involves the 1:1.5 dilution of an oil with odorless mineral spirits (OMS) containing a spectralmarker. The resulting reduction in sample viscosity facilitates the use of a transmission flow cell, with the spectralmarker serving to determine the precise dilution ratio. This allows the spectral contributions of the OMS to be eliminated and a facsimile of the neat oil spectrum to be mathematically reconstituted. The transmission- SR (T-SR) procedure was initially evaluated relative to SB-ATR to track changes in the trans content of mixtures of unhydrogenated canola and a highly hydrogenated sunflower oil (030% trans). The results indicated that the T-SR procedure had the potential to serve as the basis of an accurate quantitative method. A subsequent T-SR calibration based on the spectral ratioing principle of the SB-ATR AOAC/AOCSmethod was developed by gravimetrically adding trielaidin (04%) to extra virgin olive oil (EVO), producing an excellent linear response with a standard deviation (SD) of <0.04% trans. Subsequent comparison of SB-ATR and T-SR calibrations developed for 5 oils of different types, each spiked with low levels of trielaidin (01.2% trans), clearly indicated that SB-ATR was signal-limited, whereas the T-SR procedure performed well. The EVO calibration was subsequently used to predict the added trans content of these spiked oils, after the spectrum of the corresponding unspiked oil had been ratioed out. The resulting plot of predicted versus added trans was linear, with a slope of 1.02 and an overall SD of <0.05% trans. When the spectra of these oils were ratioed against the spectrum of EVO, the trans predictions for some of the oils were offset by 23 percentage points, emphasizing the need for the appropriate trans-free reference oil to perform accurate analyses. If the latter condition is met, then T-SR provides a very simple technique, with the potential for automation, for analysis of oils by transmission spectroscopy, with approximately 20 the sensitivity of the AOAC/AOCS SB-ATR method.

Trans determination of edible oils by fourier transform near-infrared spectroscopy

2000 ◽  
Vol 77 (10) ◽  
pp. 1061-1067 ◽  
Author(s):  
Hui Li ◽  
F. R. van de Voort ◽  
A. A. Ismail ◽  
J. Sedman ◽  
R. Cox
Keyword(s):  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Near Infrared Spectroscopy ◽  
Near Infrared ◽  
Edible Oils

Reflectance Near-Infrared Spectroscopic Method with Chemometric Techniques for Simultaneous Determination of Chondroitin, Glucosamine, and Methyl Sulfonyl Methane

2012 ◽  
Vol 95 (4) ◽  
pp. 1035-1042
Author(s):  
Alaa El-Gindy ◽  
Khalid Abdel-Salam Attia ◽  
Mohammad Wafaa Nassar ◽  
Hamed Hamed Abu Seda ◽  
Maisra Al-Shabrawi
Keyword(s):  
Simultaneous Determination ◽  
Near Infrared ◽  
Spectroscopic Method ◽  
External Validation ◽  
Pharmaceutical Preparations ◽  
Principal Component ◽  
Pharmaceutical Products ◽  
Pharmaceutical Product ◽  
Calibration Model

Abstract Reflectance near-IR (RNIR) spectroscopy was used for the simultaneous determination of chondroitin (CH), glucosamine (GO), and methyl sulfonyl methane (MSM) in tablets. Simple sample preparation was done by grinding, sieving, and compression of the tablets for improving RNIR spectra. Principal component regression and partial least squares (PLS-1 and PLS-2) were successfully applied to quantify the three components in the studied mixture using information included in RNIR spectra in the range of 4350–9100 cm–1. The calibration model was developed with drug concentration ranges of 14.5–44.2% (w/w) for CH, 18.4–55.3% (w/w) for GO, and 6–18.6% (w/w) for MSM with addition of tablet excipients to the calibration set in the same ratio as in the tested tablets. The calibration models were evaluated by internal validation, cross-validation, and external validation using synthetic and pharmaceutical preparations. The proposed method was applied for analysis of six batches of the pharmaceutical product. The results of the proposed method were compared with the results of the pharmacopoeial method for the same batch of the pharmaceutical product. No significant differences between the results were found. The RNIR method is accurate and precise, and can be used for QC of pharmaceutical products.

Reflectance Near-Infrared Spectroscopic Method with a Chemometric Technique Using Partial Least Squares Multivariate Calibration for Simultaneous Determination of Chondroitin, Glucosamine, and Ascorbic Acid

2012 ◽  
Vol 95 (3) ◽  
pp. 724-732 ◽  
Author(s):  
Alaa El-Gindy ◽  
Khalid Abdel-Salam Attia ◽  
Mohammad Wafaa Nassar ◽  
Nasr M A El-Abasawy ◽  
Maisra Al-Shabrawi Shoeib
Keyword(s):  
Ascorbic Acid ◽  
Least Squares ◽  
Simultaneous Determination ◽  
Partial Least Squares ◽  
Near Infrared ◽  
Spectroscopic Method ◽  
Pharmaceutical Products ◽  
Calibration Model ◽  
Drug Concentrations

Abstract A reflectance near-infrared (RNIR) spectroscopy method was developed for simultaneous determination of chondroitin (CH), glucosamine (GO), and ascorbic acid (AS) in capsule powder. A simple preparation of the sample was done by grinding, sieving, and compression of the powder sample for improving RNIR spectra. Partial least squares (PLS-1 and PLS-2) was successfully applied to quantify the three components in the studied mixture using information included in RNIR spectra in the 4240–9780 cm–1 range. The calibration model was developed with the three drug concentrations ranging from 50 to 150% of the labeled amount. The calibration models using pure standards were evaluated by internal validation, cross-validation, and external validation using synthetic and pharmaceutical preparations. The proposed method was applied for analysis of two pharmaceutical products. Both pharmaceutical products had the same active principle and similar excipients, but with different nominal concentration values. The results of the proposed method were compared with the results of a pharmacopoeial method for the same pharmaceutical products. No significant differences between the results were found. The standard error of prediction was 0.004 for CH, 0.003 for GO, and 0.005 for AS. The correlation coefficient was 0.9998 for CH, 0.9999 for GO, and 0.9997 for AS. The highly accurate and precise RNIR method can be used for QC of pharmaceutical products.

scholarly journals Determination of Fat,Moisture, and Protein in Meat and Meat Products by Using the FOSS FoodScan Near-Infrared Spectrophotometer with FOSS Artificial Neural Network Calibration Model and Associated Database: Collaborative Study

2007 ◽  
Vol 90 (4) ◽  
pp. 1073-1083 ◽  
Author(s):  
Shirley Anderson ◽  
S Aldana ◽  
M Beggs ◽  
J Birkey ◽  
A Conquest ◽  
...  
Keyword(s):  
Neural Network ◽  
Artificial Neural Network ◽  
Standard Deviation ◽  
Near Infrared ◽  
Collaborative Study ◽  
Meat Products ◽  
Calibration Model ◽  
Relative Standard ◽  
Infrared Spectrophotometer

Abstract A collaborative study was conducted to evaluate the repeatability and reproducibility of the FOSS FoodScan near-infrared spectrophotometer with artificial neural network calibration model and database for the determination of fat, moisture, and protein in meat and meat products. Representative samples were homogenized by grinding according to AOAC Official Method 983.18. Approximately 180 g ground sample was placed in a 140 mm round sample dish, and the dish was placed in the FoodScan. The operator ID was entered, the meat product profile within the software was selected, and the scanning process was initiated by pressing the start button. Results were displayed for percent (g/100 g) fat, moisture, and protein. Ten blind duplicate samples were sent to 15 collaborators in the United States. The within-laboratory (repeatability) relative standard deviation (RSDr) ranged from 0.22 to 2.67% for fat, 0.23 to 0.92% for moisture, and 0.35 to 2.13% for protein. The between-laboratories (reproducibility) relative standard deviation (RSDR) ranged from 0.52 to 6.89% for fat, 0.39 to 1.55% for moisture, and 0.54 to 5.23% for protein. The method is recommended for Official First Action.

Automated Fourier Transform near Infrared Determination of Buprofezin in Pesticide Formulations

2005 ◽  
Vol 13 (3) ◽  
pp. 161-168 ◽  
Author(s):  
Sergio Armenta ◽  
Javier Moros ◽  
Salvador Garrigues ◽  
Miguel de la Guardia
Keyword(s):  
Fourier Transform ◽  
High Performance ◽  
Near Infrared ◽  
Limit Of Detection ◽  
Spectroscopic Method ◽  
Sample Treatment ◽  
Pesticide Formulations ◽  
Relative Standard ◽  
On Line

An automated procedure has been developed for Fourier transform near infrared (FT-NIR) determination of buprofezin in pesticide formulations. This methodology is based on on-line pesticide extraction with acetonitrile from solid samples and its determination by using peak area absorbance measurements between 2147 and 2132 nm, corrected with a horizontal baseline established at 2091 nm. The repeatability, as a relative standard deviation of five independent analyses of 18.9 mg g−1 of buprofezin, was 0.06% and the limit of detection 5 mg L−1. The reagent consumption was clearly reduced compared with a chromatographic reference procedure from 40.4 mL acetonitrile per sample, required by high performance liquid chromatography (HPLC), to 2 mL acetonitrile consumed for FT-NIR. The sample measurement throughput obtained by the FT-NIR methodology was 30 h−1, five times higher than that obtained by HPLC (6 h−1). It can be concluded that the proposed vibrational spectroscopic method is appropriate for the quality control of commercial pesticide formulations. The on-line sample treatment avoids contact by the operator with toxic products and this method is an environmentally friendly alternative to the measurement in the mid infrared which requires the use of CHCl3.

scholarly journals Determination of glomalin in agriculture and forest soils by near-infrared spectroscopy

2017 ◽  
Vol 63 (No. 5) ◽  
pp. 226-230 ◽  
Author(s):  
Zbíral Jiří ◽  
Čižmár David ◽  
Malý Stanislav ◽  
Obdržálková Elena
Keyword(s):  
Infrared Spectroscopy ◽  
Near Infrared Spectroscopy ◽  
Forest Soils ◽  
Near Infrared ◽  
Arable Land ◽  
Calibration Model ◽  
Sustainable Land Management ◽  
Chemical Methods ◽  
Calibration Models

Determining and characterizing soil organic matter (SOM) cheaply and reliably can help to support decisions concerning sustainable land management and climate policy. Glomalin was recommended as one of possible indicators of SOM quality. Extracting glomalin from and determining it in soils using classical chemical methods is too complicated and therefore near-infrared spectroscopy (NIRS) was studied as a method of choice for the determination of glomalin. Representative sets of 84 different soil samples from arable land and grasslands and 75 forest soils were used to develop NIRS calibration models. The parameters of the NIRS calibration model (R = 0.90 for soils from arable land and grasslands and R = 0.94 for forest soils) proved that glomalin can be determined in air-dried soils by NIRS with adequate trueness and precision simultaneously with determination of nitrogen and oxidizable carbon.

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