Determination of Eicosapentaenoic, Docosahexaenoic, and Arachidonic Acids in Human Plasma by High-Performance Liquid Chromatography with Electrochemical Detection

Abstract

A high-performance liquid chromatography with electrochemical detection (HPLC-ECD) system was developed for the simultaneous determination of eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and arachidonic acid (AA) in human plasma. In the present HPLC-ECD system, EPA, DHA, and AA were separated using a reverse-phase C30 column and detected based on the voltammetric reduction of 3,5-di-tert-butyl-1,2-benzoquinone (DBBQ). Chromatographic peak areas were proportional to the concentration of EPA, DHA, and AA from 0.75 μM to 0.1 mM (r > 0.998). The concentrations of EPA, DHA, and AA in plasma from healthy human subjects after overnight fasting were determined, and the ratio of EPA to AA was obtained by the present HPLC-ECD method, which required 40 μL of human plasma and a simple procedure of sample preparation using diethyl ether extraction. Moreover, changes in EPA, DHA, and AA concentrations in a human subject were monitored before and after fish oil supplement administration by the present HPLC-ECD system.

Voltammetric Determination of Amino Acids Based on the Measurement of Reduction Prepeak of Quinone Caused by Surplus Acid after Neutralization

“…The results show that a precise FIA-ECD based on the measurement surplus of HCl has been developed for determining glutamine. Considering previous studies [25], the present method could also be applied to develop a flow through detector in HPLC.…”

“…In previous studies on the voltammetric reduction of quinones such as menadione and 3,5-di-tert-butyl-1,2-benzoquinone (DBBQ) in an unbuffered solution using bare glassy carbon and plastic formed carbon (PFC) working electrodes, the addition of small amounts of acid to the solution were found to cause a new peak (termed a prepeak) at a more positive potential than the original reduction peak of quinone itself [23][24][25][26][27]. In previous studies on the voltammetric reduction of quinones such as menadione and 3,5-di-tert-butyl-1,2-benzoquinone (DBBQ) in an unbuffered solution using bare glassy carbon and plastic formed carbon (PFC) working electrodes, the addition of small amounts of acid to the solution were found to cause a new peak (termed a prepeak) at a more positive potential than the original reduction peak of quinone itself [23][24][25][26][27].…”

“…The major aim of the present study is to develop a novel and simple detection method for determining amino acids by the use of a bare carbon working electrode where no derivatization of a sample and no modification of an electrode are necessary. In previous studies on the voltammetric reduction of quinones such as menadione and 3,5-di-tert-butyl-1,2-benzoquinone (DBBQ) in an unbuffered solution using bare glassy carbon and plastic formed carbon (PFC) working electrodes, the addition of small amounts of acid to the solution were found to cause a new peak (termed a prepeak) at a more positive potential than the original reduction peak of quinone itself [23][24][25][26][27]. The occurrence of the prepeak is ascribed to the increased proton availability of the added acid compared to the solvent molecules, leading to the reduction potential shift to a more positive direction depending on the pK a of the added acid [24].…”

Microwave-assisted Derivatization of Fatty Acids for Its Measurement in Milk Using High-Performance Liquid Chromatography

“…For examples, foods containing polyunsaturated fatty acids (PUFA), such as linoleic acid (FA18:2), linolenic acid (FA18:3), arachidonic acid (FA20:4), eicosapentaenoic acid (EPA, FA20:5) and docosahexaenoic acid (DHA, FA22:6), are generally accepted as protective agents against cardiovascular diseases. [1][2][3][4] Recent studies have revealed the potential clinical utility of mediumchain triglycerides, or the glycerol esters of medium-chain fatty acids (MCFA), in wide varieties of diseases. [5][6][7][8][9][10] In most countries, except for those where coconut or palm oils are consumed commonly, only milk and dairy products can provide a significant amount of MCFA.…”

Comparison of Methods of External and Internal Standard for Gs Determination of Docosahexaenoic Acid

“…The determination of DHA and EPA in fish oil has been reported by high-performance liquid chromatography (HPLC) (Dillon et al 2013) and HPLC with mass spectrometry (MS) detector (Lacaze et al 2017;Salm et al 2011). For simultaneous determination of DHA, EPA and arachidonic acid in human plasma, HPLC with electrochemical detector using the reversephase C30 column and detection based on the voltammetric reduction of 3,5-di-tert-butyl-1,2benzoquinone is used (Kotani et al 2016 (Vilcacundo et al 2018). GC/MS is reported with a highly polar capillary column (CP-Sil 88, 100 m) for simultaneously determination of DHA and EPA as active and fish oil nutritional capsules.…”