Coenzyme Q10 quantification in muscle, fibroblasts and cerebrospinal fluid by liquid chromatography/tandem mass spectrometry using a novel deuterated internal standard. (10th April 2013)

• Record Type: Journal Article
• Authors: Duberley, Kate E. C.; Hargreaves, Iain P.; Chaiwatanasirikul, Korn‐Anong; Heales, Simon J. R.; Land, John M.; Rahman, Shamima; Mills, Kevin; Eaton, Simon
• Is Part Of: Rapid communications in mass spectrometry. Volume 27:Number 9(2013)
• Page Start: 924
• Page End: 930
• Publication Date: 2013-04-10
• Subjects: Mass spectrometry -- Periodicals; 543.65
• DOI: 10.1002/rcm.6529
• Languages: English
• ISSNs: 0951-4198

Abstract

<abstract abstract-type="main"> <title> <x xml:space="preserve">Abstract</x> </title> <sec id="rcm6529-sec-0001" sec-type="section"> <title>RATIONALE</title> <p>Neurological dysfunction is common in primary coenzyme Q<sub>10</sub> (2, 3‐dimethoxy, 5‐methyl, 6‐polyisoprene parabenzoquinone; CoQ<sub>10</sub>; ubiquinone) deficiencies, the most readily treatable subgroup of mitochondrial disorders. Therapeutic benefit from CoQ<sub>10</sub> supplementation has also been noted in other neurodegenerative diseases. CoQ<sub>10</sub> can be measured by high‐performance liquid chromatography (HPLC) in plasma, muscle or leucocytes; however, there is no reliable method to quantify CoQ<sub>10</sub> in cerebrospinal fluid (CSF). Additionally, many methods use CoQ<sub>9</sub>, an endogenous ubiquinone in humans, as an internal standard.</p> </sec> <sec id="rcm6529-sec-0002" sec-type="section"> <title>METHODS</title> <p>Deuterated CoQ<sub>10</sub> (<italic>d<sub>6</sub></italic>‐CoQ<sub>10</sub>) was synthesised by a novel, simple, method. Total CoQ<sub>10</sub> was measured by liquid chromatography/tandem mass spectrometry (LC/MS/MS) using <italic>d<sub>6</sub></italic>‐CoQ<sub>10</sub> as internal standard and 5 mM methylamine as an ion‐pairing reagent. Chromatography was performed using a Hypsersil GOLD C4 column (150 × 3 mm, 3 µm).</p> </sec> <sec id="rcm6529-sec-0003" sec-type="section"> <title>RESULTS</title> <p>CoQ<sub>10</sub> levels were linear over a concentration range of 0–200 nM (<italic>R</italic><sup>2</sup> = 0.9995). The lower limit of detection was 2 nM. The inter‐assay coefficient of variation (CV) was 3.6% (10 nM) and 4.3% (20 nM), and intra‐assay CV 3.4% (10 nM) and 3.6% (20 nM). Reference ranges were established for CoQ<sub>10</sub> in CSF (5.7–8.7 nM; <italic>n</italic> = 17), fibroblasts (57.0–121.6 pmol/mg; <italic>n</italic> = 50) and muscle (187.3–430.1 pmol/mg; <italic>n</italic> = 15).</p> </sec> <sec id="rcm6529-sec-0004" sec-type="section"> <title>CONCLUSIONS</title> <p>Use of <italic>d<sub>6</sub></italic>‐CoQ<sub>10</sub> internal standard has enabled the development of a sensitive LC/MS/MS method to accurately determine total CoQ<sub>10</sub> levels. Clinical applications of CSF CoQ<sub>10</sub> determination include identification of patients with cerebral CoQ<sub>10</sub> deficiency, and monitoring CSF CoQ<sub>10</sub> levels following supplementation. Copyright © 2013 John Wiley & Sons, Ltd.</p> </sec> </abstract>