2:45 PM - 3:00 PM
[MZZ41-05] Investigation of comprehensive analysis of environmental chemicals and metabolome to determine the exposure effect using LC-QToFMS
Keywords:LC-MS, Environmental chemicals, Metabolomics
A substantial quantity of chemical substances exist in the environment, some of which may have adverse effects on human health and ecosystems. The vast majority of studies that monitor the presence of chemical substances in biological and environmental samples focus on specific chemicals. While the targeted compounds can be analyzed with sensitivity and precision, it remains unfeasible to comprehensive unknown substances, newly synthesized chemicals, metabolites, and the like, thereby restricting the comprehensive analysis.
Thus, in this study, we concentrate on a comprehensive analysis of environmental chemicals and attempt to exploration for environmental chemicals detected in human serum through non-targeted analysis using a high-performance liquid chromatography-tandem time-of-flight mass spectrometer (LC-QToFMS). Moreover, we also examine a method to comprehensive analysis and analyze the metabolome detected during the measurement of environmental chemical substances in order to clarify the composition of environmental chemical substance exposure and to analyze the exposure effects simultaneously.
Conversely, non-target analysis and suspect screening, which are all-inclusive analyses using high-resolution mass spectrometers, result in a larger dataset than target analysis, often yielding peaks that are over a hundred times larger. Furthermore, the types of compounds listed in high-resolution MS spectral libraries are limited, and annotation via tandem mass spectrometry matching frequently only annotates a few percent of the detected peaks, thereby presenting a challenge in compound identification.
Samples were purified through ultrafiltration following the addition of methanol and internal standards. These purified samples were subsequently analyzed using LC-QToFMS. Four analyses were conducted per sample using C18 and HILIC columns with both positive and negative polarity.
The in-house library, constructed with the NIST 20 High Resolution Tandem Mass Spectral Library, MS-DIAL metabolomics MSP spectral kit, MassBank of North America, Human Metabolome Database, Global Natural Product Social Molecular Networking, and some analytical results from our instruments, was utilized for peak annotation. The InchiKey in T3DB and the EPA DSSTox database were used to extract environmental chemicals. R ver 4.2.2 and mixOmics package was used for data cleaning and analysis.
As a result of data extraction and cleaning, 2000 compounds were extracted for annotation through high-resolution tandem mass spectrometry matching, while 200 compounds were extracted for high-resolution mass spectrometry matching. These figures were confined to approximately 10 and 1% of the total number of peaks detected, respectively, emphasizing the need to measure reference materials and expand the mass spectral library in order to augment the number of compounds that can be identified and annotated.
On the other hand, the extracted compounds comprise both endogenously sourced biological substances and environmental chemicals. Consequently, utilizing the T3DB and DSSTox databases, a list of compounds of toxicological concern was extracted. This resulted in 150 compounds being extracted for annotation through high-resolution tandem mass spectrometry matching, and 1000 compounds being extracted through high-resolution mass spectral matching for compounds of toxicological concern.
Common components from environmental chemical and metabolomic data were extracted using regularized canonical correlation analysis. The analysis the group of metabolomes correlated with certain environmental chemicals. However, the accuracy of their annotation is not necessarily assured. In the future, we aim to broaden the scope of environmental chemicals screened by identifying the annotated environmental chemical substances and upgrading the libraries and reference materials.
Thus, in this study, we concentrate on a comprehensive analysis of environmental chemicals and attempt to exploration for environmental chemicals detected in human serum through non-targeted analysis using a high-performance liquid chromatography-tandem time-of-flight mass spectrometer (LC-QToFMS). Moreover, we also examine a method to comprehensive analysis and analyze the metabolome detected during the measurement of environmental chemical substances in order to clarify the composition of environmental chemical substance exposure and to analyze the exposure effects simultaneously.
Conversely, non-target analysis and suspect screening, which are all-inclusive analyses using high-resolution mass spectrometers, result in a larger dataset than target analysis, often yielding peaks that are over a hundred times larger. Furthermore, the types of compounds listed in high-resolution MS spectral libraries are limited, and annotation via tandem mass spectrometry matching frequently only annotates a few percent of the detected peaks, thereby presenting a challenge in compound identification.
Samples were purified through ultrafiltration following the addition of methanol and internal standards. These purified samples were subsequently analyzed using LC-QToFMS. Four analyses were conducted per sample using C18 and HILIC columns with both positive and negative polarity.
The in-house library, constructed with the NIST 20 High Resolution Tandem Mass Spectral Library, MS-DIAL metabolomics MSP spectral kit, MassBank of North America, Human Metabolome Database, Global Natural Product Social Molecular Networking, and some analytical results from our instruments, was utilized for peak annotation. The InchiKey in T3DB and the EPA DSSTox database were used to extract environmental chemicals. R ver 4.2.2 and mixOmics package was used for data cleaning and analysis.
As a result of data extraction and cleaning, 2000 compounds were extracted for annotation through high-resolution tandem mass spectrometry matching, while 200 compounds were extracted for high-resolution mass spectrometry matching. These figures were confined to approximately 10 and 1% of the total number of peaks detected, respectively, emphasizing the need to measure reference materials and expand the mass spectral library in order to augment the number of compounds that can be identified and annotated.
On the other hand, the extracted compounds comprise both endogenously sourced biological substances and environmental chemicals. Consequently, utilizing the T3DB and DSSTox databases, a list of compounds of toxicological concern was extracted. This resulted in 150 compounds being extracted for annotation through high-resolution tandem mass spectrometry matching, and 1000 compounds being extracted through high-resolution mass spectral matching for compounds of toxicological concern.
Common components from environmental chemical and metabolomic data were extracted using regularized canonical correlation analysis. The analysis the group of metabolomes correlated with certain environmental chemicals. However, the accuracy of their annotation is not necessarily assured. In the future, we aim to broaden the scope of environmental chemicals screened by identifying the annotated environmental chemical substances and upgrading the libraries and reference materials.