News from LabRulezGCMS Library - Week 47, 2024

Our Library never stops expanding. What are the most recent contributions to LabRulezGCMS Library in the week of 18th November 2024? Check out new documents from the field of the gas phase, especially GC and GC/MS techniques!

👉 SEARCH THE LARGEST REPOSITORY OF DOCUMENTS ABOUT GCMS AND RELATED TECHNIQUES

👉 Need info about different analytical techniques? Peek into LabRulezLCMS or LabRulezICPMS libraries.

This week we bring you applications and posters by Agilent Technologies, Thermo Fisher Scientific, Metrohm, and Shimadzu!

1. Agilent Technologies: Determination of Carbonate Solvents and Additives in Lithium Battery Electrolyte Using the Agilent 5977B GC/MSD

• Application

Abstract

This application note describes a method for determining carbonate solvents and additives in lithium battery electrolyte using the Agilent 5977B single quadrupole gas chromatography/mass selective detector (GC/MSD). In this method, direct liquid injection is adopted. At a split ratio of 20:1, the target compounds achieved good linearity in a concentration range of 10–500 mg/L. This method has excellent reproducibility, and the instrument detection limits (IDL) for all of the 15 target compounds analyzed were below 1.3 mg/L. During the analysis of the actual electrolyte samples, diluted injection can be used to accurately quantify the target compounds and qualitatively identify unknown additives or impurities.

Introduction

Lithium battery electrolyte is the carrier of ion transport in a lithium battery, which is generally composed of lithium salt and organic solvent. In the electrolyte, the commonly used lithium salt is LiPF₆ , and the solvent is a binary, ternary, or multinary system composed of a mixture of cyclic carbonates and chain carbonates. Selecting the right organic electrolyte is the key to achieving a higher energy density, a longer cycle life, and greater battery safety. Lithium battery manufacturers also add specific additives to extend battery life. Therefore, studies on the composition of lithium battery electrolyte play an important role in the development of new lithium batteries.

GC/MS analysis is commonly used in the studies on lithium battery electrolyte, and can accurately and quantitatively analyze the major components of the organic solvent in the electrolyte. Meanwhile, the strong qualitative capacity of mass spectrometry can also qualitatively identify and analyze unknown additives and impurities.

This application note describes the method for determining carbonate and carboxylate solvents and additives in lithium battery electrolyte using the 5977B GC/MSD. In regard to the fact that LiPF₆ , the main component of the electrolyte, is unstable and can easily decompose, diluted injection was adopted, which ensured good sensitivity, linearity, and reproducibility.

Conclusion

In this application note, a method for analyzing carbonate solvents and additives in lithium battery electrolyte was developed with an Agilent 7890 GC and Agilent 5977B GC/MSD. The method is easy to use, and can achieve great separation, a wide linear range, and excellent reproducibility and sensitivity
for various components in the electrolyte, making it very suitable for qualitative and quantitative analysis of organic solvents, additives, and impurities in lithium battery electrolyte.

2. Shimadzu / AOAC: Simultaneous Analysis of Pesticides in Food With GC-MS/MS Using Hydrogen Carrier Gas

• Poster / AOAC

Introduction

In GC-MS/MS analysis, helium gas is generally used as the carrier gas; however, in recent years the shortage of supply and the soaring price of helium gas have resulted in a need to pivot to other options. To address this problem, hydrogen gas is being used as an alternative carrier gas. The characteristics of hydrogen gas are different from those of helium gas, however, and methods using helium gas must be adjusted to appropriate conditions for hydrogen gas. We have developed a quantitative analysis method for 216 pesticides with GC-MS/MS using hydrogen gas. Using this method, good recovery results were obtained in food samples.

Conclusions

Using hydrogen gas as an alternative carrier gas, we simultaneously analyzed 216 food-borne agrochemicals using an ultra-sensitive triple-quadrupole mass spectrometer GCMS-TQ8050 NX combined with AOC-30i and AOC-20s U as injectors.

Good recovery rate within 70 ~ 120% were obtained for 70% to 74% of the compounds. This system enables simultaneous analysis of multiple pesticides with high sensitivity and accuracy.

3. Thermo Fisher Scientific / RAFA: PFAS analysis strategy story – direct injection, DLLME, LC-MS/MS, LC- Orbitrap / GC-Orbitrap

• Poster / RAFA

Abstract

Purpose: This work summarizes key components of PFAS analysis. The choice between direct injection and automated sample preparation depends on the instrument's dynamic range, detection limits, and matrix complexity. Complex matrices like waste/industrial water, soil, food, and biological samples require specific preparation techniques to mitigate matrix effects and ensure accurate quantification. Techniques such as Dispersive Liquid-Liquid Microextraction (DLLME) can significantly improve concentration factors and reduce matrix interference, enhancing overall method performance. Additionally, the choice of the analyzer is a critical consideration.

Methods: Direct injection of water sample was performed on Thermo Scientific TSQ Altis Plus triple quadrupole mass spectrometer. For those sample prepared with automated dispersive liquid-liquid microextraction (DLLME), acquisition was performed on a Thermo Scientific Orbitrap Exploris MX high resolution mass spectrometer.

Results: The methods presented achieves high-level sensitivity for PFAS analysis in drinking water, detecting compounds in the low ng/L range. Using DLLME, 56 PFAS compounds were quantified to low part per trillion levels from just 15 mL of sample. With a FAPAS®-Drinking Water proficiency test, we validated the
three strategies for PFAS analysis: direct injection on TSQ Altis Plus and the DLLME extract injected on both Orbitrap Exploris MX and Thermo Scientific Orbitrap Exploris GC.

Conclusions

• Compared to traditional SPE workflows, direct injection improves sample throughput in laboratories by significantly reducing the required sample preparation.
• The DLLME method is a promising technique for extracting and pre-concentrating PFAS from drinking water and various other matrices. Its reduced sample volume facilitates easier handling, transportation, and storage.
• Both methods lower costs and environmental impact due to minimal solvent usage and the elimination of filters or SPE cartridges.
• The ease of use and robustness of both LCMS methods are based on fixed configuration including SOP with detailed hardware and consumables, a complete acquisition and processing method with customized view settings and reports, and all data handling performed with Chromeleon CDS 7.3.2.

4. Metrohm: Water content in propylene glycol monomethyl ether (PGME)

• Application

Water determination possible within seconds using NIRS

Propylene glycol monomethyl ether (1-methoxy-2-propanol, or PGME) is one of many glycol ether solvents with a wide variety of applications. It is used as an intermediate and in formulations for industrial, professional, or consumer applications, mainly in surface coatings, inks for printing, cleaning solutions, deicing/anti-icing formulations, and agrochemical purposes. It is also used as an extractant and as a coalescing agent and flow improver in water-based paints.

Water in propylene glycol methyl ether is usually measured by Karl Fischer (KF) titration which requires chemicals and takes about five minutes per determination. This Application Note describes how near-infrared spectroscopy (NIRS) can be used as a faster and more cost-efficient alternative for water determination in PGME.

CONCLUSION

This Application Note demonstrates the feasibility to determine a key parameter for the quality control of propylene glycol monomethyl ether (water content) with NIR spectroscopy. The main advantages of NIR spectroscopy over wet chemical methods are that running costs are significantly lower and time-to-result is significantly reduced. Additionally, no chemicals are required, and the technique is non-destructive to samples.