The validation & verification of an LC/MS method for the determination of total docosahexaenoic acid concentrations in canine blood serum

Evaluation of Plasma AA/DHA+EPA Ratio in Obese Romanian Children

The aim of the study was to evaluate the plasma profile of arachidonic acid (AA), docosahexaenoic acid (DHA), and eicosapentaenoic acid (EPA), as well to analyze the relationship of Omega 6/Omega 3 ratio with anthropo-metric parameters and insulin resistance markers.

Material and methods: Plasma levels of free fatty acids (FFAs) were measured using a high-throughput LC-MS AB Sciex4600 in 202 children (127 obese and 75 non-obese), age and sex-matched. Lipid and glucose profiles were assessed with current laboratory methods, while insulin resistance and beta-cell function were evaluated using HOMA-IR and HOMA-β respectively.

Results: In obese children, AA and AA/(DHA+EPA) ratio were significantly higher regardless of age and gender. In the lowest quartile of DHA, there was a clear trend for insulin resistance, with plasma insulin level, HOMA-IR, and HOMA-β significantly higher compared to the highest quartile of DHA. After adjustment for age and gender DHA remains a negative predictive factor for insulin resistance. Waist-to-height ratio (WHtR), a marker of visceral obesity was higher in children with a higher AA/(DHA+EPA) ratio.

Conclusions: In obese children, the AA is higher in concordance with insulin resistance. Additionally, children with a higher AA/(DHA+EPA) ratio have greater BMI, fat mass, waist circumference, and WHtR, important indicators of central adiposity, and cardio-metabolic disorders. LC/MS is a versatile tool for Omega ratio assessment, especially in children where the sample size is a limiting factor for metabolic and nutrition evaluation.

An Accurate Assessment of Docosahexaenoic Acid in Laying Hen Serum for Regulatory Studies

Diets rich in omega-3 fatty acids (n-3 FA) have been associated with several health benefits. With the increased interest in n-3 FA both scientifically and societally, the accurate detection of such analytes has become increasingly important. Recently, tandem mass spectrometry (MS/MS) with electrospray ionization interface (ESI), hyphenated to both gas chromatography (GC) and liquid chromatography (LC), has become a valuable tool in the detection of docosahexaenoic acid (DHA). Liquid chromatography-electrospray ionization interface-tandem mass spectrometry methods have been developed for the determination of DHA in canine and poultry species. The objective of this article is to investigate whether LC-ESI-MS/MS is fit for purpose for the determination of DHA in laying hen serum. The disclosure of this work will be beneficial for researchers investigating poultry enrichment for regulatory and toxicological studies. The method was found to be linear over the range. Precision and accuracy results met acceptance criteria and the Limit of Quantitation (LOQ) was established as 1 µg/mL. Recoveries of DHA were obtained for quality control samples and stability studies were performed. The results of the verification study complimented those of the validation study. In summation, the method was established as fit for purpose for measuring total DHA in laying hen serum.