A multiplexed dual-secondary column comprehensive two-dimensional gas chromatography approach (GC×2GC) designed for complex sample analysis is introduced. The approach splits the first-dimension column effluent into two second-dimension columns with different stationary phases, and recombines the two streams into one detector post-separation. The approach produces two single two-dimensional chromatograms for each injection. Careful manipulation of thermal modulator timing parameters combined with a novel contra-directional modulation regime facilitates this approach. A selection of 34 laboratory reference compounds containing n-alkanes, alcohols, aromatic hydrocarbons, ketones, esters and halogenated hydrocarbons were analysed to demonstrate the approach. The dual two-dimensional chromatogram from this single detector system provides complementary information due to the unique selectivity of the three separation columns. The results of this proof-of-principle investigation provide significant impetus for further development of GC×2GC-MS methodology.
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http://dx.doi.org/10.1016/j.aca.2013.05.013 | DOI Listing |
Environ Res
December 2024
School of Civil Engineering, Shandong University, Jinan 250061, China. Electronic address:
The structure and active components of the filling material play a critical role in the contamination remediation performance of permeable reactive barriers. However, current methods lack a comprehensive understanding of the structural evolution and long-term performance of these materials during remediation processes. This study utilizes column experiments combined with spectral induced polarization (SIP) monitoring to investigate the effectiveness of zero-valent iron (ZVI), activated carbon (AC), and their composite with sand in removing Cr(VI).
View Article and Find Full Text PDFMicrobiol Spectr
December 2024
National Center for Polar and Ocean Research, Ministry of Earth Sciences, Vasco-da-Gama, Goa, India.
Deep sea microbial communities play a significant role in global biogeochemical processes. However, the depth-wise metabolic potential of microbial communities in hydrothermally influenced Central Indian Ridge (CIR) and Southwest Indian Ridge (SWIR) remains elusive. In this study, a comprehensive functional microarray-based approach was used to understand factors influencing the metabolic potential of microbial communities and depth-driven differences in microbial functional gene composition in CIR and SWIR.
View Article and Find Full Text PDFFood Chem
December 2024
Department of Applied Chemistry ⋅ Food Science and Technology, Dong-eui University, Busan, Republic of Korea. Electronic address:
In this study, a robust and validated UHPLC-QqQ-MS/MS method was developed to quantify anserine and carnosine levels and their ratios to distinguish the geographical origin of red seabream (Pagrus major) from Japan and Korea. Comprehensive optimization of column types, mobile phase pH, organic solvent ratios, and internal standards identified the optimal conditions: an HILIC column at pH 5 with 75 % acetonitrile and PEH as the internal standard. The method exhibited excellent sensitivity, linearity, accuracy, and precision, establishing anserine as the most reliable biomarker for origin discrimination.
View Article and Find Full Text PDFThe spurdog (Squalus acanthias Linnaeus, 1758) is a globally distributed squaliform shark that has historically been overfished but is now recovering in the northeast Atlantic. Data series on spurdog movement and habitat use have been somewhat limited to research surveys due to challenges associated with electronic tagging. Here, we offer a revised attachment method for externally attached pop-up satellite archival tags that was successful in long-term deployments on pregnant females.
View Article and Find Full Text PDFJ Chromatogr A
December 2024
Department of Chemical Engineering, University College London, Torrington Place, London, WC1E 7JE, UK. Electronic address:
To elevate the separation performance, two-dimensional liquid chromatography (2D-LC) uses two chromatographic columns with different stationary phases to diversify solute interactions with the resin, hence providing a second "dimension" to solute-specific separation. Developing methods for 2D-LC starts therefore with preliminary column selection. Selecting columns that yield (metaphorically) orthogonal dimensions is of utmost importance, but remains challenging.
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