Simultaneous determination of five essential amino acids in plasma of Hyperlipidemic subjects by UPLC-MS/MS

Abstract

Background: Millions of adults have been reported with hyperlipemia in the world. It is still unclear whether the plasma level of essential amino acids (AAs) will be influenced by the hyperlipemia. This study was aimed to investigate the AAs levels and the underlying metabolic relationship in hyperlipidemic subjects. Methods: An ultra-high performance liquid chromatography-tandem mass spectrometric (UPLC-MS/MS) method was developed for the determination of phenylalanine (Phe), valine (Val), histidine (His), tryptophan (Trp), and methionine (Met). Plasma samples (100 μL) were precipitated by acetonitrile (300 μL) and analyzed on a BEH C18 (2.1 mm × 100 mm, 1.7 μm) column at 40°C by gradient elution. The mobile phase composed of 0.1% formic acid and acetonitrile was used with flow rate at 0.2-0.4 ml/0-3 min. Five AAs were determined at positive electrospray ionization (ESI+) at m/z 118.1/72.1 (Val), 150.12/104.02(Met), 156.06/110.05(His), 166.1/120.1(Phe), and 205.2/188.02 (Trp). A total of 75 healthy subjects and 83 hyperlipidemic subjects, who had blood routine test and plasma lipid test were determined by developed UPLC-MS/MS. Results: It was shown that there was good linearity for Val, Met, His, Phe, and Trp within 1-100 μg/mL. The relative standard deviations of precision and accuracy were all within 15%. The level of Val, Phe, Trp, His, and Met were 35.34 ± 15.64, 22.72 ± 9.13, 17.23 ± 4.94, 16.78 ± 13.64, and 6.24 ± 1.97 μg/mL in healthy subjects, while they were 38. 04 ± 16.70, 22.41 ± 8.45, 15.62 ± 5.77, 18.35 ± 14.49, and 6.21 ± 1.97 μg/mL in hyperlipidemic subjects respectively. The Spearman's correlations analysis showed that there were high correlations between Val, Phe, Trp, His, Met and triglyceride in healthy subjects. While, those correlations decreased in hyperlipemia cases. Conclusion: A convenient and sensitive method for simultaneous determination of Val, Phe, Trp, His, and Met in human plasma was developed. There was a high correlation between Val, Phe, Trp, His, Met and triglyceride. Hyperlipemia influences the metabolic balance of His, Phe, Trp, Met and Val.

UHPLC-MS/MS Technique: Applications in Analytical Chemistry

“…The use of time-of-flight mass detection can facilitate the structural identification of proteins. Most of the applications for the analysis of amino acids and proteins were carried out by using UPLC BEH amide C-18 column, composition of water and acetonitrile, with 0.3% formic acid (in gradient elution mode) as mobile phase and ESI-QTOF-MS/MS detection technique [108][109][110][111][112][113][114][115][116][117][118][119][120][121][122][123]. Examples analyzed biomolecules and applied UHPLC-MS/MS conditions are presented in Table -8.…”

Nanofibers comprising polystyrene and zinc acetate for extraction of salivary histidine prior to its determination by HPLC–DAD

“…including mass spectrometry 15 , spectrofluorimetry 16,17 , amino acid analyzer 18 , naked-eye detection 19 , and high-performance liquid chromatography (HPLC) [20][21][22] . As the most common method, pre-or post-column derivatization protocols are most common in HPLC analysis due to the lack of strong chromophores in histidine molecule.…”

Considerations for amino acid analysis by liquid chromatography-tandem mass spectrometry: A tutorial review

“…Some methods use differing additives/buffers in each of the selected solvents to get sufficient chromatographic separation without sacrificing intensity in the mass spectrometer. One example of this is seen in Chen et al [64] where the aqueous solvent is 0.1% formic acid, while the organic ACN has no additive.…”