Analytical problems with the determination of coenzyme Q₁₀ in biological samples

Abstract

The article discusses analytical problems related to the determination of coenzyme Q10 in biological samples. The assaying of coenzyme Q10 in complex samples, such as plasma, tissues, or food items requires meticulous sample preparation prior to final quantification. The process typically consists of the following steps: deproteinization, extraction, and ultimately reduction of extract volumes. At times drying under a gentle stream of neutral gas is applied. In the case of solid samples, a careful homogenization is also required. Each step of the sample preparation process can be a source of analytical errors that may lead to inaccurate results. The main aim of this work is to point to sources of analytical errors in the preparation process and their relation to physicochemical properties of coenzyme Q10. The article also discusses ways of avoiding and reducing the errors.

LC/MS/MS analysis of α‐tocopherol and coenzyme Q10 content in lyophilized royal jelly, beebread and drone homogenate

“…A mass of about 0.5 g of royal jelly was weighted and transferred into the 10‐ml test tube. As methanol is commonly used as deproteinization agent for biological matrixes, it was used for this purpose in our experiments . The 0.5‐g portion of the sample was mixed with 1 ml of methanol and 1 ml of n ‐hexane.…”

“…As methanol is commonly used as deproteinization agent for biological matrixes, it was used for this purpose in our experiments. [29,30] The 0.5-g portion of the sample was mixed with 1 ml of methanol and 1 ml of n-hexane. The tube was shaken for 2 min and sonicated for 30 min.…”

CoQ10 Deficiency May Indicate Mitochondrial Dysfunction in Cr(VI) Toxicity

“…Briefly, 250 μL of samples and 750 μL of hexane:ethanol (5:2, v / v ) were mixed together for 1 min using a vortex mixer. The mixture was centrifuged for 3 min at 4000× g , and 450 μL of the hexane layer was collected, dried under a stream of nitrogen, and dissolved in 100 μL of ethanol (1:1, v / v ) [58]. Quantification of CoQ10 was performed by HPLC according to Lass and Sohal [59].…”

The Value of Coenzyme Q10 Determination in Mitochondrial Patients

“…CoQ levels in a range of specimen types from patients with mitochondrial diseases have been demonstrated to be lower than control values [6,7,16,17]. However, the particular CoQ distribution in distinct cellular fractions and the complexity of biological matrices makes the biological sample choice and preparation a critical step in the CoQ quantification process [18]. Additionally, since CoQ deficiency may be tissue-specific [19], invasive procedures are frequently needed in order to assess endogenous CoQ in the target organ, especially in muscle.…”