scholarly journals Comparison of Two Derivatization Methods for the Analysis of Fatty Acids andTransFatty Acids in Bakery Products Using Gas Chromatography

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Jumat Salimon ◽  
Talal A. Omar ◽  
Nadia Salih
Keyword(s):  
Fatty Acids ◽  
Gas Chromatography ◽  
Methyl Esters ◽  
Correlation Coefficients ◽  
Bakery Products ◽  
Trimethylsilyl Diazomethane ◽  
Acid Catalyzed ◽  
High Level ◽  
Level Of Agreement

Two different procedures for the methylation of fatty acids (FAs) andtransfatty acids (TFAs) in food fats were compared using gas chromatography (GC-FID). The base-catalyzed followed by an acid-catalyzed method (KOCH3/HCl) and the base-catalyzed followed by (trimethylsilyl)diazomethane (TMS–DM) method were used to prepare FA methyl esters (FAMEs) from lipids extracted from food products. In general, both methods were suitable for the determination ofcis/transFAs. The correlation coefficients (r) between the methods were relatively small (ranging from 0.86 to 0.99) and had a high level of agreement for the most abundant FAs. The significant differences (P=0.05) can be observed for unsaturated FAs (UFAs), specifically for TFAs. The results from the KOCH3/HCl method showed the lowest recovery values (%R) and higher variation (from 84% to 112%), especially for UFAs. The TMS-DM method had higherRvalues, less variation (from 90% to 106%), and more balance between variation and %RSD values in intraday and interday measurements (less than 4% and 6%, resp.) than the KOCH3/HCl method, except for C12:0, C14:0, and C18:0. Nevertheless, the KOCH3/HCl method required shorter time and was less expensive than the TMS-DM method which is more convenient for an accurate and thorough analysis of richcis/transUFA samples.

Direct ultrasound-assisted methylation of fatty acids in serum for free fatty acid determinations

2010 ◽  
Vol 88 (9) ◽  
pp. 898-905 ◽  
Author(s):  
Liyan Liu ◽  
Ying Li ◽  
Rennan Feng ◽  
Changhao Sun
Keyword(s):  
Mass Spectrometry ◽  
Fatty Acids ◽  
Gas Chromatography ◽  
Fatty Acid ◽  
Fatty Acid Methyl Esters ◽  
Methyl Esters ◽  
Ultrasonic Waves ◽  
Acid Methyl ◽  
Ultrasound Assisted

A method for simultaneous determination of 16 free fatty acids (FFAs) in serum is described. The method involves conversion of FFAs to fatty acid methyl esters (FAMEs) using the heat of ultrasonic waves followed by gas chromatography and mass spectrometry (GC–MS) analysis. Optimum levels of the variables affecting the yield of FAMEs were investigated. The results indicate that the optimal levels are 55 °C, 60 W, 10% H2SO4/CH3OH, and 50 min. Recoveries ranged from 85.32% to 112.11%, with a detection limit ranging from 0.03 to 0.08 μg mL–1. The linearity, using the linear correlation coefficient, was higher than 0.9914.

scholarly journals DETERMINATION OF FATTY ACIDS IN SOLANUM SURATTENSE BURM. F. BY USING GAS CHROMATOGRAPHY

2017 ◽  
Vol 10 (8) ◽  
pp. 60 ◽  
Author(s):  
Raman Preet ◽  
Raghbir Chand Gupta
Keyword(s):  
Fatty Acids ◽  
Gas Chromatography ◽  
Fatty Acid ◽  
Methyl Esters ◽  
Basic Research ◽  
Fatty Acid Analysis ◽  
Operating Conditions ◽  
Solanum Surattense ◽  
Flame Ionization

  Objective: This study aims to document the fatty acid composition of Solanum surattense Burm. f. collected from hot desert of India, Rajasthan.Methods: The fatty acid analysis was performed by gas chromatography-flame ionization detector (GC-FID). The operating conditions used to examine methyl esters of fatty acids are as follows. Fatty acids were converted into methyl esters (FAMEs) before GC analysis according to the standard methods by Ranganna (1986). Quantitative determinations of FAMEs were conducted using GC-FID and capillary column HP-88 Agilent Technologies.Results: The most abundant fatty was palmitic acid (13.2%), oleic acid (22.9%), and linoleic acid (11.9%). This plant is good source of important fatty acids including all the groups of saturated, monounsaturated, and polyunsaturated fatty acids (MUFAs and PUFAs) and can be used as a commercial source of fatty acids especially MUFAs and PUFAs.Conclusion: The plant is well studied for various pharmacological activities such as antiasthmatic, anticancer, cardiovascular, and hepatoprotective. Determination of fatty acid profiles in nutritional and clinical research with precision and fastness has become popular for human health and basic research.

The Comparability of Job Evaluation Methods in Supplying Approximately Similar Classifications in Rating One Job Series

1982 ◽  
Vol 12 (2) ◽  
pp. 38-40 ◽  
Author(s):  
R.J. Snelgar
Keyword(s):  
South Africa ◽  
Evaluation Method ◽  
Correlation Coefficients ◽  
Evaluation Methods ◽  
Job Evaluation ◽  
High Level ◽  
High Degree ◽  
Level Of Agreement ◽  
Similar Classification

There is a belief that any job evaluation method, when correctly applied to a series of jobs, will result in approximately the same rating classification as that supplied by any other method for the same job series. This study was aimed primarily at a determination of the extent to which a number of job evaluation methods, differing in methodology, and presently in use within South Africa on a national basis, would in fact supply similar classification. Correlation coefficients among the ratings supplied by participating organizations, in terms of points allocation for each job subsequent to evaluation according to job evaluation factors (raw point ratings), were unexpectedly high. These correlations ranged from 0,93 to 0,99, with an average of 0,98, indicating a remarkably high level of agreement. Correlations were properly transformed, and mean correlations of each organization with every other organization subsequently calculated. These mean correlations ranged from 0,96 to 0,98, once again indicating a high degree of commonality.

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