News from LabRulezGCMS Library - Week 36, 2024

Our Library never stops expanding. What are the most recent contributions to LabRulezGCMS Library in the week of 2nd September 2024? Check out new documents from the field of the gas phase, especially GC and GC/MS techniques!

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This week we bring to you applications and technical notes by Agilent Technologies, Shimadzu, and Thermo Fisher Scientific!

1. Shimadzu: Residual NMP and Solvent Analysis in Lithium-ion Battery Cathode

• application

User Benefits

• Analyze residual NMP and similar solvent structures in the cathode of lithium-ion batteries.
• Optimize drying conditions in the cathode manufacturing process and quantify the amount of residual solvents for quality control.
• Minimize equipment footprint by combining Brevis GC-2050 and GCMS-QP2050.

Introduction: Lithium-ion batteries (LiB) consist of cathode and anode, electrolyte, separator, etc. The electrodes are formed by coating a slurry of active material, conductive additives, binders, etc., mixed
in an organic solvent, on a metal film (current collector) and then dried. N-Methyl-2-pyrrolidone (NMP) is known as an organic solvent used in solvent-based slurries, and especially for quality control of the cathode, the residual amount of NMP in the cathode is examined during the drying process.

In this application, a simple analysis method for residual NMP in the cathode of lithium-ion battery NCM (nickel-cobalt-manganese ternary material) using GC-FID with headspace method is introduced. In addition, results of qualitative analysis of other solvents remaining in the NCM cathode using GC-MS and
comparison of residual solvent amounts in five different cathodes with different drying processes are also presented.

Summary: By using headspace GC-FID, it is possible to easily analyze residual NMP in the cathode and quantify residual solvents without the need for preprocessing. Additionally, with headspace GC-MS, qualitative analysis of residual organic solvents can also be performed.

Using compact models such as Brevis GC-2050 or GCMS-QP2050 allows for minimization of experimental space and detailed analysis of solvent analysis for each drying process. This can be applied to quality control and research and development in the cathode manufacturing process.

2. Agilent Technologies: A Forensic Triple Quadrupole GC/MS MRM Database for Forensic and Toxicological Workflows

• application

Abstract: Systematic toxicological analysis is crucial in forensic laboratories, requiring robust and reliable analytical methods. Gas chromatography coupled to triple quadrupole mass spectrometry (GC/TQ) is a versatile and widely used technique that provides uniform results across instruments and laboratories. The aim of this study was to establish a database of multiple reaction monitoring (MRM) transitions for
toxicologically relevant compounds amenable to GC/MS. The resulting curated database includes 176 entries, including 154 unique compounds with up to 12 transitions per compound. The database allows for instantly building methods for targeted screening and confident quantitation of GC-amenable, forensic, and toxicologically relevant compounds.

The database is available for download as a CSV file in Appendix 1 of this application note.

Conclusion: The forensic toxicology database, with a curated set of 1,803 MRM transitions for 176 toxicologically relevant compounds, was successfully developed. The compounds included  benzodiazepines, antidepressants, opioids, and drugs of abuse. The application of this MRM method to
an authentic real-world sample showcased its ability to detect and quantitate toxicants at trace levels due to the high sensitivity and selectivity of the MS/MS approach. This approach addresses limitations when relying solely on full scan data acquisition mode.

The developed MRM database can be used for simplified data acquisition method creation, providing a valuable resource for the development of screening and quantitation methods in forensic labs. The developed MRM curation workflow showed promise for continuous expansion, offering a uniform and practical approach for adding new chemicals to the database.

3. Agilent Technologies: Optimizing HydroInert EI Source Functionality and Longevity

• technical note

Introduction: The benefits of hydrogen in gas chromatography (GC) are widely accepted, as it can be generated in the lab in a cost-effective manner, produces fast chromatography, and allows for higher sample throughput. Since hydrogen is a reactive gas, hydrogenation and dechlorination reactions can and do occur in the mass spectrometer electron ionization (EI) source. These reactions can make applying hydrogen carrier gas to many applications difficult. A specially designed extractor source for the Agilent Inert Plus GC/MSD and triple quadrupole GC/MS systems address these hydrogen-related issues and improves performance with hydrogen carrier gas. The Agilent HydroInert source (Figure 1) with H₂ carrier gas retains mass spectral fidelity and can allow users to continue to use existing helium-based mass spectral libraries.

When adopting hydrogen for GC/MS analysis, there are several factors to consider. First, hydrogen is a reactive gas, and it may potentially cause chemical reactions in the inlet, column, and sometimes the MS EI source, which can change analysis results. To address potential issues in the MS source while using hydrogen, the HydroInert source was used. Additional information can be found in the Agilent technical overview of the HydroInert source.¹ Second, for GC/MS applications, hardware changes in the gas chromatograph and mass spectrometer are recommended when switching to hydrogen carrier gas. The Agilent Helium to Hydrogen Carrier Gas Conversion Guide² describes in detail the steps for conversion from helium to hydrogen carrier gas. Lastly, it is recommended that when working with flammable or explosive gases, laboratories maintain proper safety in gas handling and use. Further information on the
safe use of hydrogen can be found in the Agilent Hydrogen Safety Manual³ and Hydrogen Safety for the Agilent GC System Guide.^4,5

Conclusion: Agilent HydroInert source longevity is dependent on application and method conditions. However, by using some of the best practices highlighted above, the longevity of HydroInert parts can be prolonged. The HydroInert source cannot be mechanically or chemically cleaned, thus when source parts show reduced functionality, replacement of the recommended parts above is required to restore functionality. Replacement intervals will be method- and application-dependent.

4. Thermo Fisher Scientific: Improvements for the analysis of volatile (VOC) and very volatile (VVOC) organic compounds using In-Tube Extraction- Dynamic Headspace (ITEX-DHS) and cryogen-free refocusing

• application

Goal: To demonstrate how the technological development of dynamic headspace extraction/enrichment techniques, such as ITEX-DHS (In-Tube Extraction-Dynamic Headspace) coupled to a cryogen-free refocusing in the PTV injector, enables the achievement of lower detection limits for volatile and very volatile organic compounds.

Keywords: VOC, VVOC, water, dynamic headspace, ITEX-DHS, refocusing, PTV, TRACE 1610 GC, TriPlus RSH SMART autosampler

Conclusion: The use of the ITEX-DHS technique for headspace enrichment coupled to cryogen-free refocusing into the PTV injector is a suitable approach for trace level analysis of VOC and VVOC in water samples, offering a clean method to comply with more stringent regulatory limits of quantitation.

• Combined with refocusing prior to transfer into the column and SIM acquisition mode, the ITEX-DHS technique achieves limits of quantification at low ppt levels and extrapolated limits of detection in the sub-ppt range, even for VVOC such as vinyl chloride, with high recovery precision (<5% RSD) and a linear response over four orders of magnitude.
• ITEX-DHS offers a flexible enrichment technique capable of handling low and high concentrated samples to comply with different sensitivity requirements.
• The complete workflow, from method set up to data processing and reporting, can be fully controlled through Chromeleon CDS, which greatly facilitates operations on a day-to-day basis.