Determination of iodine value with a fourier transform‐near infrared based global calibration using disposable vials: An international collaborative study

Abstract

A method for the determination of iodine value (IV) by Fourier transform-near infrared (FT-NIR) spectroscopy was developed and evaluated in an international collaborative study. The FT-NIR analyzer employed in this work uses disposable vials for sample handling and incorporates validation protocols designed to ensure that the calibration will give accurate results from analyzer to analyzer and stability over time without any further calibration development work. The global IV calibration was developed from over 1,200 animal, marine, and vegetable oils and fats, which were obtained on a number of different instruments worldwide. The Standard Error of Cross Validation measured from a range of 0-190 IV varied from ±0.2-1.4 IV (1 sigma). The repeatability for all models was on the order of 0.1 IV, which states that most of the error was inherited from the primary methods. Finally, an international interlaboratory study was carried out with 16 samples obtained from the AOCS Smalley Laboratory Proficiency Program and an oil processor. The average reproducibility error in any one lab was better than 0.15, and the average reproducibility between labs was better than 0.33. An uncertainty of 0.45 was calculated from the average FT-NIR values obtained from the collaborative study vs. the AOCS Certified Wijs method (Cd 1d-92).

Quantitative determination of free fatty acids in extra virgin olive oils by multivariate methods and Fourier transform infrared spectroscopy considering different absorption modes

“…[7][8][9] The McGill IR Group has already developed various spectroscopic methods using Fourier Transform Infrared (FTIR) in combination with chemometrics techniques as alternatives to the official titrimetric methods in the quantitative determination of important quality parameters of oils and fats such as saponification number, [10] iodine value, [10][11][12][13] cis and trans content, [10,13] peroxide value, [14][15][16] and moisture. [17] For the determination of FFAs in EVOOs using spectroscopic methods, a number of articles have been published.…”

Comparative Study on Oxidative Decomposition Behavior of Vegetable Oils and Its Correlation with Iodine Value Using Thermogravimetric Analysis

“…To reduce the use of toxic solvent, cyclohexane 3,4) has been substituted as a replacement for chloroform in Wijs method but longer reaction time is required especially for oils with higher IV. Other reported alternative methods with minimum solvent consumption were flow injection analysis (FIA) 5) , Fourier transform infrared spectroscopy (FTIR) 6) , near infrared spectroscopy (NIR) 7,8) , 1 H nuclear magnetic resonance spectroscopy ( 1 H NMR) 9) , differential scanning calorimetry (DSC) 10) and high performance liquid chromatography (HPLC) 11,12) . DSC was the first reported thermal method for IV determination in palm oil.…”

Spectroscopy: Developments in instrumentation and analysis

“…Today the trend lies in the development of validated spectroscopic methods based on internationally accepted guidelines. Various collaborative studies of spectroscopic methods have been published (Adam et al 2000;Cox et al 2000).…”