Premium
Coenzyme Q 10 quantification in muscle, fibroblasts and cerebrospinal fluid by liquid chromatography/tandem mass spectrometry using a novel deuterated internal standard
Author(s) -
Duberley Kate E. C.,
Hargreaves Iain P.,
Chaiwatanasirikul KornAg,
Heales Simon J. R.,
Land John M.,
Rahman Shamima,
Mills Kevin,
Eaton Simon
Publication year - 2013
Publication title -
rapid communications in mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.528
H-Index - 136
eISSN - 1097-0231
pISSN - 0951-4198
DOI - 10.1002/rcm.6529
Subject(s) - chemistry , chromatography , coenzyme q10 , high performance liquid chromatography , tandem mass spectrometry , mass spectrometry , liquid chromatography–mass spectrometry , detection limit , deuterium , biochemistry , physics , quantum mechanics
RATIONALE Neurological dysfunction is common in primary coenzyme Q 10 (2,3‐dimethoxy, 5‐methyl, 6‐polyisoprene parabenzoquinone; CoQ 10 ; ubiquinone) deficiencies, the most readily treatable subgroup of mitochondrial disorders. Therapeutic benefit from CoQ 10 supplementation has also been noted in other neurodegenerative diseases. CoQ 10 can be measured by high‐performance liquid chromatography (HPLC) in plasma, muscle or leucocytes; however, there is no reliable method to quantify CoQ 10 in cerebrospinal fluid (CSF). Additionally, many methods use CoQ 9 , an endogenous ubiquinone in humans, as an internal standard. METHODS Deuterated CoQ 10 ( d 6 ‐CoQ 10 ) was synthesised by a novel, simple, method. Total CoQ 10 was measured by liquid chromatography/tandem mass spectrometry (LC/MS/MS) using d 6 ‐CoQ 10 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). RESULTS CoQ 10 levels were linear over a concentration range of 0–200 nM ( R 2 = 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 10 in CSF (5.7–8.7 nM; n = 17), fibroblasts (57.0–121.6 pmol/mg; n = 50) and muscle (187.3–430.1 pmol/mg; n = 15). CONCLUSIONS Use of d 6 ‐CoQ 10 internal standard has enabled the development of a sensitive LC/MS/MS method to accurately determine total CoQ 10 levels. Clinical applications of CSF CoQ 10 determination include identification of patients with cerebral CoQ 10 deficiency, and monitoring CSF CoQ 10 levels following supplementation. Copyright © 2013 John Wiley & Sons, Ltd.