Simple and Sensitive Method for the Quantitative Determination of Lipid Hydroperoxides by Liquid Chromatography/Mass Spectrometry

Abstract

Lipid hydroperoxides (LOOH) are the initial products of the peroxidation of unsaturated lipids and play a crucial role in lipid oxidation due to their ability to decompose into free radicals and cause adverse effects on human health. Thus, LOOHs are commonly considered biomarkers of oxidative stress-associated pathological conditions. Despite their importance, the sensitive and selective analytical method for determination is limited, due to their low abundance, poor stability, and low ionizing efficiency. To overcome these limitations, in this study, we chemically synthesized eight fatty acid hydroperoxides (FAOOH), including FA 18:1-OOH, FA 18:2-OOH, FA 18:3-OOH, FA 20:4-OOH, FA 20:5-OOH, FA 22:1-OOH, FA 22:6-OOH as analytes, and FA 19:1-OOH as internal standard. Then, they were chemically labeled with 2-methoxypropene (2-MxP) to obtain FAOOMxP by one-step derivatization (for 10 min). A selected reaction monitoring assisted targeted analytical method was developed using liquid chromatography/tandem mass spectrometry (LC-MS/MS). The MxP-labelling improved the stability and enhanced the ionization efficiency in positive mode. Application of reverse-phase chromatography allowed coelution of analytes and internal standards with a short analysis time of 6 min. The limit of detection and quantification for FAOOH ranged from 0.1–1 pmol/µL and 1–2.5 pmol/µL, respectively. The method was applied to profile total FAOOHs in chemically oxidized human serum samples (n = 5) and their fractions of low and high-density lipoproteins (n = 4). The linoleic acid hydroperoxide (FA 18:2-OOH) and oleic acid hydroperoxide (FA 18:1-OOH) were the most abundant FAOOHs in human serum and lipoproteins. Overall, our validated LC-MS/MS methodology features enhanced detection and rapid separation that enables facile quantitation of multiple FAOOHs, therefore providing a valuable tool for determining the level of lipid peroxidation with potential diagnostic applications.

Lipoprotein Profile in Immunological Non-Responders PLHIV after Antiretroviral Therapy Initiation

“…Indeed, LDL-P, and more specifically the increased presence of small LDL-P, was found to be associated with a higher atherosclerotic risk [ 15 ], whereas an important representation of HDL-P in circulation seemed to be inversely associated with carotid intima–media thickness [ 16 ]. Thus, the recent methodology based on a two-dimensional spectra (2D) from diffusion-ordered NMR spectroscopy (DOSY) experiments (Liposcale ® test) provides not only lipid concentration but also lipoprotein size, and lipoprotein particle numbers of the main fractions and subclasses compared to liquid chromatography/tandem mass spectrometry (LC-MS/MS) which also offers a valuable tool for determining a lipid profile with potential diagnostic applications due to its sensitivity and rapid separation limited to lipid concentrations [ 17 , 18 ].…”

Mathematical Modeling of Alpha-Tocopherol Early Degradation Kinetics to Predict the Shelf-Life of Bulk Oils

“…While the specific range of 0.025–0.1 is not directly mentioned in the papers, several studies have discussed the importance of careful monitoring lipid oxidation in food products due to its significant impact on food quality and shelf life . These studies highlight the need for accurate and sensitive methods for the quantitative analysis of lipid oxidation . In Perera et al, lipid oxidation was assessed in terms of the free fatty acid level and peroxide value, indicating the importance of precise measurements in these experiments.…”

“…30 These studies highlight the need for accurate and sensitive methods for the quantitative analysis of lipid oxidation. 31 In Perera et al, 32 lipid oxidation was assessed in terms of the free fatty acid level and peroxide value, indicating the importance of precise measurements in these experiments. Zullig et al 33 emphasized the need for particular care when analyzing degradation or oxidation products of lipids, especially when their concentrations are expected to be very low.…”

Lipidomics of Microplasma-Irradiated Cells at Optimized Discharge Conditions for the Absorption of High-Molecule Drug

“…However, we could not find any oxidized lipid species in the irradiated cells. This could be due to the analytical challenges, such as the low abundance, poor stability, the limited ionization efficiency of oxidized lipids [25,26], and the limitations of lipid annotation tools. Our findings are consistent with a previous study, wherein the oxidative modification of skin lipids by CAP was investigated by MS/MS, but oxidized lipid species was rarely detected [27].…”