Applying a risk assessment guided evaluation for verifying comprehensive two-dimensional gas chromatography to analyse complex pharmaceuticals

Abstract

The reliability of analytical results is critical and indispensable when applied in regulated environments such as the pharmaceutical industry. Therefore, analytical workflows must be validated. However, validation guidelines are often designed for quantitative targeted analysis and rarely apply to qualitative untargeted approaches. In this study, we employ a risk assessment approach to identify critical parameters which might influence the qualitative results derived by online derivatisation — comprehensive two-dimensional gas chromatography coupled to a high-resolution time-of-flight mass spectrometer (GC × GC-HR-ToF–MS) for the analysis of the active pharmaceutical ingredient (API) sodium bituminosulfonate (SBS). To show the complexity and feasibility of such an approach, we focus on investigating three potential risk factors: sample preparation, vapourability, and the thermal stability of sulfonates. Through the individual evaluation of these potential risk factors due to the application of sample preparation approaches and thermal gravimetric analysis (TGA), we demonstrate the high derivatisation efficiency and repeatability of the online derivatisation method and confirm the absence of derivatisation-induced side reactions. In addition, we also show the potential thermal instability of an incompletely derivatised API. To address the limitation of these individual assessments, we applied a holistic evaluation step with negative electrospray ionisation Fourier transform ion cyclotron resonance mass spectrometry (ESI( −) FT-ICR MS) as an orthogonal technique. This confirms that most of the API is detected via the presented GC-based method. Thereby, we demonstrated the practical feasibility of the risk assessment-based approach to ensure the validity of the qualitative data for a complex untargeted method. Graphical Abstract

Rock-to-Pharma: Characterization of Shale Oil-Based Nonbiological Complex Drugs along the Production Process by High-Resolution Mass Spectrometry

“…The GC × GC measurements were carried out on a Pegasus GC-HRT 4D (LECO, St. Joseph, USA). 15,31 In summary, a 60 m BP1 (0.25 mm internal diameter, 0.25 μm film thickness, SGE) column was used in the first dimension and 1.5 m BPX50 (0.1 mm internal diameter, 0.1 μm film thickness, SGE) in the second dimension. Before the measurement, the APIs were mixed with tetramethylammonium hydroxide (1:2 w/v) and diluted 1:10 with a mixture of water/methanol (1:1 v/v).…”

“…GCxGC group-type analysis (Figure S13C) revealed distinct DBE-specific structural moieties for each compound class (e.g., thiophene-and benzothiophenesulfonates (DBE 3 and DBE 6, respectively) for CHO 3 S 2 ). Therefore, the abundances of isomers found by GCxGC EI HR-ToF-MS analysis can be summed up to obtain data sets which are comparable to the direct infusion FT-ICR MS data, 31 allowing for an alignment of these data sets according to their assigned sum formulas. This further allows to tentatively transfer the structural elucidation achieved by the GCxGC analysis to the direct infusion ESI(−) data set.…”

“…28,29 Molecular information can be gained by highperformance chromatography combined with mass spectrometry. 28,30 However, the development of chromatographic protocols can be tedious 31 and error-prone. Unlike chromatography, most atmospheric pressure ionization techniques are directly applicable with minimal to no sample preparation.…”

“…Unlike chromatography, most atmospheric pressure ionization techniques are directly applicable with minimal to no sample preparation. 31 Thus, direct mass spectrometry with atmospheric pressure ionization has become increasingly popular in pharmaceutical research lately. 32 High-field Fourier-transform ion cyclotron resonance mass spectrometry (FT-ICR MS) has been successfully deployed for in-depth molecular speciation of dissolved organic matter, 33 fossil fuels, 34 proteins, as well as other complex organic mixtures.…”

“…15 However, gas chromatography reaches its instrumental limits for higher molecular weight NBCDs, such as ABS. 31 Direct injection mass spectrometry may overcome these limitations and enable immediate complex mixture analysis. However, as the molecular formulas attribution relies on resolving isobaric constituents without chromatography, particularly heteroelements can be problematic.…”