High-accuracy analysis system for the redox status of coenzyme Q10 by online supercritical fluid extraction–supercritical fluid chromatography/mass spectrometry

Facilitated on-line supercritical fluid extraction - supercritical fluid chromatography for nonpolar and polar compounds from milk thistle seeds

Plant seeds, as those from milk thistle (Silybum marianum), are a valuable source of nonpolar and polar compounds with potentially interesting biological activity. The main nonpolar compounds are triglycerides, which are also the main components of all vegetable oils. In addition, specific polar compounds - flavonolignans, called silymarin, have been found in large amounts in milk thistle seeds extract. These flavonoids derivatives have different biological activity, for instance hepatoprotective effects. In order to extract and analyze both nonpolar (triglycerides) and polar compounds (flavonolignans) from milk thistle seeds through a sequential methodology, an on-line supercritical fluid extraction - supercritical fluid chromatography (SFE-SFC) method was developed. Different ways of transferring the extracts from SFE to SFC (i.e. direct on-column transfer and loop transfer) were compared, and particularly for their effect on chromatographic quality. In this respect, nonpolar and polar compounds caused different issues, especially as polar compounds required a significant portion of co-solvent in the extraction step, favoring early elution in the chromatographic column. First, on-line SFE-SFC was used for triglycerides analysis and allowed the comparison of transfer modes. Then, on-line kinetics were performed to measure defatting time before polar molecules extraction. Finally, the eventual benefit of loop transfer was also investigated for the analysis of flavonolignans, polar molecules whose analysis can be difficult by on-line SFE-SFC. The aim of this paper is to discuss the versatility of on-line SFE-SFC and how challenging the coupling can be, especially when both non-polar and polar molecules must be analyzed independently in a single sample.

Online SFE-SFC-MS/MS colony screening: A high-throughput approach for optimizing (-)-limonene production

Conventional analysis of microbial bioproducers requires the extraction of metabolites from liquid cultures, where the culturing steps are time consuming and greatly limit throughput. To break through this barrier, the current study aims to directly evaluate microbial bioproduction colonies by way of supercritical fluid extraction-supercritical fluid chromatography-triple quadrupole mass spectrometry (SFE-SFC-MS/MS). The online SFE-SFC-MS/MS system offers great potential for high-throughput analysis due to automated metabolite extraction without any need for pretreatment. This is the first report of SFE-SFC-MS/MS as a method for direct colony screening, as demonstrated in the high-throughput screening of (-)-limonene bioproducers. Compared with conventional analysis, the SFE-SFC-MS/MS system enables faster and more convenient screening of highly productive strains.

On-line coupling of supercritical fluid extraction with enantioselective supercritical fluid chromatography-triple quadrupole mass spectrometry for the determination of chiral pesticides in hemp seeds: A proof-of-principle study

The present research can be considered as a proof-of-principle study focused on the determination of chiral pesticides using a supercritical fluid extraction instrument coupled on-line with an enantioselective supercritical fluid chromatography-triple quadrupole mass spectrometry. To the best of Authors' knowledge, this is the first description of an on-line approach for the extraction and determination of chiral pesticides. Metalaxyl, benalaxyl and dimethenamid were investigated in nine hemp seed samples belonging to four varieties of Cannabis sativa; only in one case a pesticide was found at levels above the method limit of quantification (LoQ), though within the EU maximum residue level value. The figures-of-merit determined were linearity, precision, limit of detection (LoD), and LoQ. Regression coefficients were between 0.9856 and 0.9973, the LoDs were in the 0.04-0.41 μg kg^-1 range, the LoQs were in the 0.12-1.38 μg kg^-1 range, while coefficients of variation were between 1 and 3% (10 μg kg^-1 level).

Development of a practical online supercritical fluid extraction-supercritical fluid chromatography/mass spectrometry system with an integrated split-flow method

Herein, we describe a practical online supercritical fluid extraction-supercritical fluid chromatography/mass spectrometry (SFE-SFC/MS) system with an integrated split-flow method and a pre-column trap method that is well suited for the continuous extraction and separation of a wide range of compounds, including hydrophilic ones. Although an SFE-SFC system with a splitting method is already commercially available, in this study, we added some new features to this system: 1) a splitting method that further reduces the amount of extractant introduced into SFC, 2) a trap column, connected before the analytical column, with a different separation mechanism than the analytical column in the system with the splitting method, and 3) a system for calculating the recovery rate of SFE during online SFE-SFC/MS. In the above setup, part of the analyzed extract is introduced into the separation section at a higher split ratio owing to the make-up pump flow rate, thus reducing the distortion of the target analyte peak shape caused by the use of a strong extractant. Furthermore, the separation efficiency is improved by the use of an additional pre-column capable of interacting with compounds weakly retained on the analytical column. Finally, we show that equalization of the SFE and autosampler injection conditions allows evaluation of the recovery rate of SFE during online SFE-SFC/MS.

The many (inter-)faces of supercritical fluid chromatography: the present and future prospects of online supercritical fluid extraction–supercritical fluid chromatography

Automated supercritical fluid extraction–supercritical fluid chromatography is an innovative method with low-effort sampling strategies (e.g., dried blood spots) that may make large-scale application faster, cheaper and greener than currently thought possible.

Automated statistical experimental design approach for rapid separation of coenzyme Q10 and identification of its biotechnological process related impurities using UHPLC and UHPLC-APCI-MS

A novel ultra high performance liquid chromatography method development strategy was ameliorated by applying quality by design approach. The developed systematic approach was divided into five steps (i) Analytical Target Profile, (ii) Critical Quality Attributes, (iii) Risk Assessments of Critical parameters using design of experiments (screening and optimization phases), (iv) Generation of design space, and (v) Process Capability Analysis (Cp) for robustness study using Monte Carlo simulation. The complete quality-by-design-based method development was made automated and expedited by employing sub-2 μm particles column with an ultra high performance liquid chromatography system. Successful chromatographic separation of the Coenzyme Q10 from its biotechnological process related impurities was achieved on a Waters Acquity phenyl hexyl (100 mm × 2.1 mm, 1.7 μm) column with gradient elution of 10 mM ammonium acetate buffer (pH 4.0) and a mixture of acetonitrile/2-propanol (1:1) as the mobile phase. Through this study, fast and organized method development workflow was developed and robustness of the method was also demonstrated. The method was validated for specificity, linearity, accuracy, precision, and robustness in compliance to the International Conference on Harmonization, Q2 (R1) guidelines. The impurities were identified by atmospheric pressure chemical ionization-mass spectrometry technique. Further, the in silico toxicity of impurities was analyzed using TOPKAT and DEREK software.

Lipidomics by Supercritical Fluid Chromatography

This review enlightens the role of supercritical fluid chromatography (SFC) in the field of lipid analysis. SFC has been popular in the late 1980s and 1990s before almost disappearing due to the commercial success of liquid chromatography (LC). It is only 20 years later that a regain of interest appeared when new commercial instruments were introduced. As SFC is fully compatible with the injection of extracts in pure organic solvent, this technique is perfectly suitable for lipid analysis and can be coupled with either highly universal (UV or evaporative light scattering) or highly specific (mass spectrometry) detection methods. A short history of the use of supercritical fluids as mobile phase for the separation oflipids will be introduced first. Then, the advantages and drawbacks of SFC are discussed for each class of lipids (fatty acyls, glycerolipids, glycerophospholipids, sphingolipids, sterols, prenols, polyketides) defined by the LIPID MAPS consortium.

Randomized, double-blind, placebo-controlled pilot trial of reduced coenzyme Q10 for Parkinson's disease

INTRODUCTION

Mitochondrial complex I deficiencies have been found in post-mortem brains of patients with Parkinson's disease (PD). Coenzyme Q10 (CoQ10) is the electron acceptor found in complexes I and II, and is a potent antioxidant. A recent trial of the oxidized form of CoQ10 for PD failed to show benefits; however, the reduced form of CoQ10 (ubiquinol-10) has shown better neuroprotective effects in animal models.

METHODS

Randomized, double-blind, placebo-controlled, parallel-group pilot trials were conducted to assess the efficacy of ubiquinol-10 in Japanese patients with PD. Participants were divided into two groups: PD experiencing wearing off (Group A), and early PD, without levodopa (with or without a dopamine agonist) (Group B). Participants took 300 mg of ubiquinol-10 or placebo per day for 48 weeks (Group A) or 96 weeks (Group B).

RESULTS

In Group A, total Unified Parkinson's Disease Rating Scale (UPDRS) scores decreased in the ubiquinol-10 group (n = 14; mean ± SD [-4.2 ± 8.2]), indicating improvement in symptoms. There was a statistically significant difference (p < 0.05) compared with the placebo group (n = 12; 2.9 ± 8.9). In Group B, UPDRS increased in the ubiquinol-10 group (n = 14; 3.9 ± 8.0), as well as in the placebo group (n = 8; 5.1 ± 10.3).

CONCLUSIONS

This is the first report showing that ubiquinol-10 may significantly improve PD with wearing off, as judged by total UPDRS scores, and that ubiquinol-10 is safe and well tolerated.

Supercritical fluid chromatography/mass spectrometry in metabolite analysis

Supercritical fluid chromatography (SFC) owes many of its advantages to the properties of supercritical CO2, which possesses benefits as mobile phase. SFC has recently gained attention as a separation technique because it can be utilized for not only non-polar but also polar compound analysis. In addition, MS is widely adopted for SFC, and the options for MS are equivalent to liquid chromatography. Sensitive and selective detection is crucial in metabolite analysis. The SFC/MS system can be an alternative approach to liquid chromatography, as can metabolite analysis using packed-column SFC in biosamples. In this review we cover the fundamentals of SFC in combination with MS, and discuss the results of metabolite analysis using SFC/MS.

Analytical problems with the determination of coenzyme Q10 in biological samples

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.