A capillary electrophoretic system based on a novel microemulsion for the analysis of coenzyme Q10 in human plasma by electrokinetic chromatography

Abstract

A new analytical method for determination of coenzyme Q10 (2,3-dimethoxy-5-methyl-6-decaprenyl-1,4-benzoquinone, CoQ10) in human plasma was developed based on CE using a double tensioactive microemulsion. CoQ10 was quantitatively extracted into 1-propanol/hexane and quantified by MEEKC. The microemulsion was prepared by mixing 1.4% w/w sodium bis(2-ethylhexyl) sulfosuccinate, 4% w/w cholic acid, 1% w/w octane, 8.5% w/w butanol, 0.1% w/w PVA and 85% w/w 10 mM Tris buffer at pH 9.0. The optimized electrophoretic conditions included the use of an uncoated silica capillary of 60 cm total length and 75 mum id, an applied voltage of 20 kV, room temperature and 214 nm ultraviolet detection. Selectivity, linearity, LOD, LOQ, precision and accuracy were evaluated as the parameters of validation. Owing to its simplicity and reliability, the proposed method can be an advantageous alternative to the traditional methodology for the quantitation of CoQ10 in human plasma with good accuracy and precision.

Advances in the theory and application of MEEKC

“…Generally pH is optimised between 7 and 9 [40,49,51], and this results in a high EOF with a fast and efficient separation. However, pH values as high as 12 or as low as 2 may be required [52] depending on the pK a of the analytes under investigation and whether there is a need to eliminate ion-pair interactions.…”

“…From late 2008 to 2009 MEEKC has been applied to the analysis of vitamins [40], bioanalysis [51], natural products [79] and antibiotics [80]. Table 1 specifies the optimised ME composition and separation application for all reports in this paper.…”

“…An MEEKC method [51] utilising the double-chain surfactant sodium bis(2-ethylhexyl) sulphosuccinate and cholic acid was applied to the quantitative determination of the highly hydrophobic coenzyme Q10 (2,3-dimethoxy-5methyl-6-decaprenyl-1,4-benzoquinone) in human plasma. The optimised MEEKC method was validated and compared with a standard HPLC method.…”

“…Separation of highly hydrophobic structurally related corticosteroids 3.6% w/w SDS, 6.6% w/w 1-butanol, 0.8% w/w n-octane and 89% w/w 40 mM sodium dihydrogen phosphate buffer pH 8.0 [49] Enantioseparation of ephedrine and pseudoephedrine 2% R/S DDCV, 1.65% v/v 2-hexanol, 1.23% v/v diethyl tartrate and 50 mM sodium phosphate buffer pH 7.0 [59] Detection and separation of ephedrine and pseudoephedrine employing laser-induced fluorescence detection 3.24% w/w n-heptane, 3.24% w/w SDS, 26.44% w/w 1-butanol and 95% 50 mM sodium borate buffer containing 16% ACN pH 7 [69] Separation and determination of flavonoids employing electrochemical detection 0.9% w/v SDS, 0.9% w/v SC, 0.9% w/v 1-butanol, 0.6% w/v ethyl acetate and 98.2% v/v 10 mM sodium tetraborate buffer pH 7.5 [70] Determination of the coenzyme Q10 (2,3-dimethoxy-5-methyl-6-decaprenyl-1,4-benzoquinone) in human plasma 1.4% w/w sodium bis(2-ethylhexyl) sulphosuccinate (AOT), 4% w/w cholic acid, 8.5% w/w butanol, 1% w/w octane, 0.1% w/w PVA and 85% w/w 10 mM Tris buffer pH 9.0 [51] Fingerprint analysis and extraction of resina draconis 3.3% w/v SDS, 6.6% w/v 1-butanol, 0.8% w/v n-octane and 10 mM sodium tetraborate buffer pH 9.2 [79] Separation and determination of NF antibiotics in fish 3.48% w/w SDS, 6.48% w/w 1-butanol, 0.82% w/w octane and 10 mM sodium tetraborate buffer pH 9.70 [80] Separation of phenolic acids and diterpenoids using W/O MEEKC 48% w/v 1-butanol, 18% w/v SDS, 8.0% w/v 2-propanol and 26% v/v sodium acetate buffer pH 6.0 [82] Electrophoresis 2010, 31,[755][756][757][758][759][760][761][762][763][764][765][766][767] have been shown to be both mutagenic and carcinogenic. The ME was optimised in terms of surfactant, co-surfactant and oil concentration with the optimum buffer being composed of 0.82% w/w octane, 3.48% w/w SDS and 6.48% w/w butanol in a 10 mM sodium borate buffer pH 9.70.…”

Determination by UPLC/MS-MS of Coenzyme Q10 (CoQ10) in Plasma of Healthy Volunteers before and after Oral Intake of Food Supplements Containing CoQ10

“…For these reasons in the last few years, the number of CoQ10 dietary supplements has increased rapidly. Several analytical methods have been developed for the determination of CoQ10 content, based on spectrophotometric, colorimetric [27], electrochemical [28,29] and electrophoretic techniques [30], but the method of choice is reversed phase high performance liquid chromatography (LC) with ultraviolet detection [31,32], electrochemical detection [33][34][35] or tandem mass spectrometry detection (MS/MS) [36,37]. The more recent reports deals with the development of miniaturized LC/UV systems [38] and the demonstration of the effect of CoQ10 in the reduction of the oxidative stress and of the inflammatory markers [39,40].…”