Pattern-Type Separation of Triacylglycerols by Silver Thiolate×Non-Aqueous Reversed Phase Comprehensive Liquid Chromatography

Abstract

Triacylglycerols (TAGs), as the main components of edible oils and animal fats, are responsible for the nutritional value, organoleptic features and technological properties of foods; each lipid matrix shows a unique TAG profile which can serve as fingerprint to ensure the quality and authenticity of food products. The high complexity of many foodstuffs often makes untargeted elucidation of TAG components a challenging task; thus, more efficient separation techniques may be mandatory. In this research, the TAG profile of a borage (Borago officinalis) seed oil was obtained by two-dimensional comprehensive liquid chromatography (LC×LC), by the coupling of silver thiolate and octadecylsilica monodisperse materials. A total 94 TAG compounds were identified by ion trap-time of flight detection, using atmospheric pressure ionization, with the degree of unsaturation varying from 0 to 9, and partition values ranging from 36 to 56. The group-type separation afforded by this analytical approach may be useful to quickly fingerprint TAG components of oil samples.

Comprehensive and heart‐cutting multidimensional liquid chromatography–mass spectrometry and its applications in food analysis

“…The two mechanisms most frequently used for the analysis of TAGs in complex food samples are nonaqueous reverse liquid chromatography (NA‐RPLC) and silver ion liquid chromatography (Ag‐LC). The orthogonality offered by the combination of these separation mechanisms has been effectively applied for the 2D‐LC analysis of TAGs in edible oils (P. Arena et al, 2021; J. Hu et al, 2013; Wei et al, 2015, 2013). In NA‐RPLC, the retention of TAGs depends on the equivalent carbon number (ECN), whereby the higher ECN, the higher retention.…”

“…In contrast, the major popularity of APCI derives from the loss of a fatty acid that generates intense diacylglycerol ion fragments [DAG] + , providing important information regarding the structure and position of fatty acids (Cacciola et al, 2017). This is why APCI is the most widely used technique as it allows efficient ionization of nonpolar compounds such as TAGs, as well as is highly compatible with the mobile phases used in NA‐RPLC systems (P. Arena et al, 2021; Byrdwell et al, 2017; J. Hu et al, 2013; Wei et al, 2015, 2013).…”

Ammonia Concentration in the Eluent Influences Fragmentation Pattern of Triacylglycerols in Mass Spectrometry Analysis

“…Additionally, methodologies encompassing shot-gun or direct infusion versus separation by liquid chromatography before MS detection are currently used and are a matter of debate regarding their efficiency [ 5 , 6 , 16 ]. Therefore, active research concerning the influence of other factors on the fragmentation information quality, as well as the application of diverse methodologies, is ongoing at present regarding TAG analysis [ 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 ].…”