Collaborative test of determination of iodine value in fish oils. 2. Carbon tetrachloride or cyclohexane/acetic acid as solvents

Abstract

Nine laboratories participated in a collaborative test to determine the iodine value (IV) of eight samples of fish oil (four with IV < 150; four with IV > 150) with either carbon tetrachloride (AOCS Official Method Cd 1-25) or cyclohexane/acetic acid (AOCS Recommended Practice Cd 1d-92) as solvent and 1 h of reaction time. Laboratories received coded duplicate samples (hidden duplicates) and carried out duplicate determinations on each oil by each method (open duplicates).Replacing carbon tetrachloride with cyclohexane/acetic acid resulted in similar mean values for both low-and high-IV oils and similar estimates of repeatability and reproducibility. The repeatability standard deviation (s r ), based on hidden duplicates, with carbon tetrachloride and cyclohexane/acetic acid were 1.71 and 1.55, respectively. The corresponding reproducibility standard deviations were 1.81 and 1.98.

Determination of Iodine Value in Hydrogenated Oils: Comparison of Titration and Gas Chromatography with Flame‐Ionization Detection Methodologies

“…This emulsion layer often led to an overshooting of the endpoint (Barlow et al, ). Challenges associated with the emulsion were reportedly overcome by replacing cyclohexane with a 50:50 mixture of cyclohexane and glacial acetic acid (Barlow et al, ). In contrast, we observed more favorable titrations with the cyclohexane solvent (i.e.…”

Process Characterization Studies for Solvent-Free Simultaneous Epoxidation and Transesterification of Fatty Acid Methyl Esters

“…The content of double bonds in starting materials and the progress of epoxidation reaction indicated by the decrease of the content of double bonds in the reaction mixture was performed via iodine value titration published by Wij . Therefore, 0.1 g of the analyte were weighed into a 100 mL Erlenmeyer flask and diluted with 10 mL of cyclohexane/acetic acid 1:1 mixture.…”

Chloramine‐T with iodine: A new reagent to determine the lodine value of edible oils. Part II

“…Chloramine-T was also found to reduce cobra venom factor activity (10). However, since our method (1) involves the use of carbon tetrachloride, which is a known carcinogen, we suggest here a modification replacing carbon tetrachloride by any one among the relatively safe solvents, namely solvent I: cyclohexane + acetic acid (1:1, vol/vol) or solvent II: acetic acid, or solvent III: cyclohexane, which have been employed as alternative solvents to carbontetrachloride in the context of studies on fish oils (11)(12)(13). In the proposed modification, the reagent is once again cost-effective, can be prepared in the laboratory in a short time, is stable for more than a week, and the solvents employed are safe.…”