Determination of sulfur contents of vegetable and marine oils by ion chromatography and indirect ultraviolet photometry of their combustion products

Abstract

A simple method for the determination of total sulfur content in vegetable and marine oils is described. The method involves combustion of the oil sample in an oxygen bomb to convert all forms of sulfur to sulfate ions with subsequent determination of the sulfate by ion chromatography and indirect ultraviolet detection. The ultraviolet system described is more sensitive than conductivity detection and enables the method to be applied more widely.Application of the method to a variety of vegetable and marine oils showed the general occurrence of sulfur in fats and oils, albeit often at a low level. Among the samples examined, crude Canola oil had the highest sulfur content (25.0 mg/kg) followed by the marine oils (5.8-15.2 mg/kg} and the non-Cruciferae vegetable oils {2.0-6.

Effect of Support Acidic Properties on Sulfur Tolerance of Pd Catalysts for Partial Hydrogenation of Rapeseed Oil‐Derived FAME

“…Vegetable oil in the Cruciferae family such as rapeseed and canola oils are known to contain sulfur (S) compounds [3], which are powerfully poisonous to the catalysts. However, the work carried out on S tolerance of the catalyst particularly for partial hydrogenation of polyunsaturated FAME has not been done.…”

Determination of nitrogen content of fats and oils by the method of combustion/ion chromatography

“…Ion chromatography coupled with indirect UV detection is a convenient method for quantitative analysis of anions (2). Under the conditions used in this study chloride, nitrite, nitrate, sulfate and selenate ions were well separated from each other ( Fig.…”

“…Initially, triacetin was tested according to the previous procedure (2), in which sample degassing was not carried out and no oxygen-filled glove-bag was used. Surprisingly, the combustion products contained nitrite as well as Figs.…”

Current Research Developments on the Processing and Improvement of the Nutritional Quality of Rapeseed (Brassica napus L.)

“…However, trace amounts of enzymatic hydrolysis products of glucosinolates are still present in canola oil . Daun and Hougen showed that crude oil can contain about 10–50 mg kg −1 sulfur, which is mostly removed during conventional refining process to 9 mg kg −1 or less . These organic compounds can poison the catalysts applied for hydrogenation and give the characteristic odor to the oil.…”

“…[94] Daun and Hougen [95] showed that crude oil can contain about 10-50 mg kg À1 sulfur, which is mostly removed during conventional refining process to 9 mg kg À1 or less. [96] These organic compounds can poison the catalysts applied for hydrogenation and give the characteristic odor to the oil. Simultaneously, sulfur components may increase stability of the oil acting as antioxidants.…”