Related Experiment Video
Updated: Jan 21, 2026

Quantification of Coenzyme A in Cells and Tissues
Published on: September 27, 2019
Characterization of unknown impurities in Coenzyme Q10 using LC-MS and NMR
Yunfei Deng1, Xiaoping Chen2, Linbo Wang2
1School of Pharmacy, China State Institute of Pharmaceutical Industry, Shanghai, 201203, China; Shanghai Institute for Food and Drug Control, Shanghai, 201203, China.
Abstract:
During studies on related substances in coenzyme Q10 (CoQ10) active pharmaceutical ingredient (API) and capsules, two impurities (Impurity 1 and Impurity 2) with each content more than 0.1% attracted our attention. Accelerated testing (40 °C /75%RH) and forced degradation of CoQ10 API and drug products in different stress conditions (base and heat) gave rise to the two unknown impurities. These unknown impurities were separated by reverse phase ultra-performance liquid chromatography (UPLC), where they were eluted at 0.77 (Impurity 1) and 1.10 (Impurity 2) relative retention times to CoQ10 peak. Impurity 2 was separated into two peaks (Impurity 2-1 and Impurity 2-2) by normal phase high performance liquid chromatography (NP-HPLC). In this study, an ultra-performance liquid chromatography complied with quadrupole time-of-flight tandem mass spectrometry (UPLC-QTOF/MS) via atmospheric pressure chemical ionization (APCI) was used to identify the proposed structure of the three impurities (Impurity 1, Impurity 2-1 and Impurity 2-2). We got the three impurities through preparative high performance liquid chromatography and their structures were further confirmed by 1D and 2D nuclear magnetic resonance (NMR). Based on the significance of these results, Impurity 1 was the impurity E referred in British Pharmacopoeia (BP), Impurity 2-1 and Impurity 2-2 were a pair of isomers which had not been reported before.
More Related Videos
Related Concept Videos
Cofactors and Coenzymes
Cofactors and Coenzymes
Cofactors can be metallic ions or organic molecules called coenzymes. These types of helper...
Testing a Claim about Mean: Unknown Population SD
Estimating a population mean requires the samples to be approximately normally distributed. The data should be collected from the randomly selected samples having no sampling bias. There is no specific requirement for sample size. But if the sample size is less than 30, and we don't know the population standard deviation, a different approach is used;...
Estimating Population Mean with Unknown Standard Deviation
William S. Gosset (1876–1937) of the...
Role of Reduced Coenzymes NADH and FADH₂
¹³C NMR: ¹H–¹³C Decoupling
A broadband decoupling technique is used to simplify these complex, sometimes overlapping, signals. Broadband decoupling relies on a...

