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bioRxiv · 10.1101/2021.01.18.424378

Human Tear Metabolomics Using Liquid Chromatography-Q Exactive-HF Mass Spectrometry

Shrestha, G. S.·Vijay, A. K.·Stapleton, F.·Pickford, R.·Carnt, N.
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Abstract

AimTo putatively identify and characterise human tear metabolites in a normal subject on an untargeted platform of liquid chromatography-Q exactive-HF mass spectrometry. MethodsFour samples of unstimulated tears were collected from both eyes on four consecutive days between 1 - 2 pm using a microcapillary tube and pooled from both eyes each day. Untargeted analysis of the tears was performed by chromatographic separation of constituent metabolites in both CSH-C18RP (Charged Surface Hybrid-C18 Reversed Phase) and SeQuant ZIC-pHILIC (Zwitterionic-polymeric Hydrophilic Interaction Liquid Chromatography) columns, followed by heated electrospray ionization (HESI) and the acquisition of mass spectra using QExactive-HF mass spectrometer. Compound Discoverer software (v2.0) was used for data analysis. ResultEighty-two metabolites were tentatively identified. Seventy compounds (85.4 %) were observed in all four samples with a coefficient of variation (CV) less than 25 %. Fifty-nine metabolites (71.9 %) were novel in the healthy tears. Amino acids were the most frequently detected metabolites in the tears (28 %), followed by carbohydrates (12.2 %), carboxylic acids (8.5 %), carnitines (6.1 %) and glycerophospholipids (4.9 %), respectively. ConclusionThe current untargeted platform is capable of detecting a range of tear metabolites across several biological categories. This study provides a baseline for further ocular surface studies.

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Shrestha, G. S., Vijay, A. K., Stapleton, F., Pickford, R., Carnt, N.. 2021-01-18. Human Tear Metabolomics Using Liquid Chromatography-Q Exactive-HF Mass Spectrometry. https://doi.org/10.1101/2021.01.18.424378

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