scholarly journals Evaluation of a Raman spectroscopic method for the determination of alcohol content in Greek spirit Tsipouro

2016 ◽  
Vol 4 (Special-Issue-October) ◽  
pp. 01-09 ◽  
Author(s):  
Christos Pappas ◽  
Basalekou Marianthi ◽  
Elina Konstantinou ◽  
Niki Proxenia ◽  
Stamatina Kallithraka ◽  
...  
Keyword(s):  
Spectroscopic Method ◽  
Alcohol Concentration ◽  
Calibration Model ◽  
Alcohol Content ◽  
Raman Spectroscopic ◽  
Band Area ◽  
Starting Point ◽  
Pre Treatment ◽  
Relative Errors

A Raman spectroscopic method and the conventional distillation method for the determination of alcohol content % (v/v) in Greek spirit Tsipouro used. A univariate calibration model was constructed employing the band area at 880 cm-1 of standard ethanol solutions. The concentrations of 46 samples were then measured using the calibration model and the results were compared with those obtained using the conventional analysis employing a distillation step. Alcohol content in Greek spirit Tsipouro measured with the conventional method ranged from 35.1 to 71.2 % (v/v). The determination coefficient (R2) value was 0.9997 while the corresponding values of the relative errors ranged between – 13.1 -1.0 %. According to the proposed method the alcohol concentration in Greek spirit Tsipouro ranged from 27.7 to 68.2 % (v/v). The proposed method is simple, rapid, economical and does not require any sample pre-treatment steps. It could be a starting point for the design of more specific models according to the requirements of the spirit industry.

An in situ Raman spectroscopic method for quantification of polyethylene glycol (PEG) in waterlogged archaeological wood

Holzforschung ◽  
2020 ◽  
Vol 74 (11) ◽  
pp. 1043-1051
Author(s):  
Åke Henrik-Klemens ◽  
Katarina Abrahamsson ◽  
Charlotte Björdal ◽  
Alexandra Walsh
Keyword(s):  
Polyethylene Glycol ◽  
Spectroscopic Method ◽  
Calibration Model ◽  
Efficient Treatment ◽  
Raman Spectroscopic ◽  
Archaeological Wood ◽  
Validation Set ◽  
Impregnation Period ◽  
Polymer Impregnation

AbstractThe weakened microstructure of archaeological wood (AW) objects from waterlogged environments necessitates consolidation to avoid anisotropic shrinkage upon drying. Polymer impregnation through submergence or spraying treatments is commonly applied, and for larger and thicker objects, the impregnation period can stretch over decades. Thus, for efficient treatment, continuous monitoring of the impregnation status is required. Today, such monitoring is often destructive and expensive, requiring segments for extraction and chromatographic quantification. This study proposes an in situ Raman spectroscopic method for quantification of polyethylene glycol (PEG) in waterlogged AW. A calibration model was built on standards of PEG, cellulose powder, and milled wood lignin using orthogonal partial least squares (OPLS). The OPLS model had a strong linear relationship, and the PEG content in wood of varying degrees of degradation could be determined. However, the accuracy of the model was low with a root mean square error of prediction of 11 wt%. The low accuracy was traced to the heterogeneity in the calibration and validation set samples with regard to the small probing volume of the confocal instrumental setup.

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 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.

Fast and non-destructive Raman spectroscopic determination of multi-walled carbon nanotube (MWCNT) contents in MWCNT/polydimethylsiloxane composites

The Analyst ◽  
2018 ◽  
Vol 143 (18) ◽  
pp. 4347-4353
Author(s):  
Donghyun Ryoo ◽  
Jong Yun Kim ◽  
Pham Khac Duy ◽  
Sang Hoon Cho ◽  
Hoeil Chung ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Spectroscopic Method ◽  
Spectroscopic Determination ◽  
Raman Spectroscopic ◽  
Multi Walled Carbon Nanotube ◽  
Non Destructive

A versatile Raman spectroscopic method to determine the contents of carbon nanotubes (CNTs) in CNT/polydimethylsiloxane (PDMS) composites is demonstrated, and important issues directly related to the accuracy of the measurement were investigated.

A Raman spectroscopic method for the determination of high pressure vapour liquid equilibria

2013 ◽  
Vol 360 ◽  
pp. 265-273 ◽  
Author(s):  
Renata Adami ◽  
Julian Schuster ◽  
Sara Liparoti ◽  
Ernesto Reverchon ◽  
Alfred Leipertz ◽  
...  
Keyword(s):  
High Pressure ◽  
Spectroscopic Method ◽  
Raman Spectroscopic

Determination of the International Sensitivity Index of a New Near-Patient Testing Device to Monitor Oral Anticoagulant Therapy

1997 ◽  
Vol 78 (02) ◽  
pp. 855-858 ◽  
Author(s):  
Armando Tripodi ◽  
Veena Chantarangkul ◽  
Marigrazia Clerici ◽  
Barbara Negri ◽  
Pier Mannuccio Mannucci
Keyword(s):  
Linear Relationship ◽  
Whole Blood ◽  
Oral Anticoagulant ◽  
Oral Anticoagulant Therapy ◽  
Oral Anticoagulants ◽  
Calibration Model ◽  
Testing Device ◽  
Data Points ◽  
Near Patient Testing

SummaryA key issue for the reliable use of new devices for the laboratory control of oral anticoagulant therapy with the INR is their conformity to the calibration model. In the past, their adequacy has mostly been assessed empirically without reference to the calibration model and the use of International Reference Preparations (IRP) for thromboplastin. In this study we reviewed the requirements to be fulfilled and applied them to the calibration of a new near-patient testing device (TAS, Cardiovascular Diagnostics) which uses thromboplastin-containing test cards for determination of the INR. On each of 10 working days citrat- ed whole blood and plasma samples were obtained from 2 healthy subjects and 6 patients on oral anticoagulants. PT testing on whole blood and plasma was done with the TAS and parallel testing for plasma by the manual technique with the IRP CRM 149S. Conformity to the calibration model was judged satisfactory if the following requirements were met: (i) there was a linear relationship between paired log-PTs (TAS vs CRM 149S); (ii) the regression line drawn through patients data points, passed through those of normals; (iii) the precision of the calibration expressed as the CV of the slope was <3%. A good linear relationship was observed for calibration plots for plasma and whole blood (r = 0.98). Regression lines drawn through patients data points, passed through those of normals. The CVs of the slope were in both cases 2.2% and the ISIs were 0.965 and 1.000 for whole blood and plasma. In conclusion, our study shows that near-patient testing devices can be considered reliable tools to measure INR in patients on oral anticoagulants and provides guidelines for their evaluation.

UV spectroscopic method for determination of phenytoin in bulk and injection forms

2019 ◽  
Author(s):  
Chem Int
Keyword(s):  
Quality Control ◽  
Spectrophotometric Method ◽  
Spectroscopic Method ◽  
Ich Guidelines ◽  
Precision And Accuracy ◽  
Routine Quality Control

Recent study was conducted to develop a simple UV spectrophotometric method to determine Phenytoin in bulk and injection form according to official requirement and validate as per ICH guidelines. λmax of Phenytoin was found 202 nm. Linearity existed perceived in the concentration assortment 2-8 μg/ml (r2 = 0.999) for the method. The method was validated pertaining to linearity, precision and accuracy studies, LOD and LOQ consistent with ICH guidelines. The existent method was establish to be simple, linear, precise, accurate as well as sensitive and can be applied for routine quality control enquiry for the analysis of Phenytoin in bulk and injection form.

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