Abstract
Biological thiol amino acids have been suggested as biomarkers for pathological changes because they are reactive chemicals that participate in various physiological processes. In this study, multisegmented injection capillary electrophoresis–mass spectrometry with online sample preconcentration was used for analysis of thiol amino acids and intermediates of sulfur metabolism in human glioma cell line U-251 with high accuracy, throughput, and sensitivity. This was achieved using multiple, large-volume injections for online sample preconcentration. The 16 intermediates of sulfur metabolism had a good linear correlation coefficient range of 0.984–1 and the limit of detection range was 1.4–203.9 ng/mL. The recovery ranges of most amino acids were 88.1–114.5%, 89.0–104.3%, and 76.9–104.5% at 0.3, 0.75, and 1.5 μg/mL, respectively. The relative standard deviation ranges for the inter- and intra-day precision were 1.8–10.7% and 4.3–18.8%, respectively. Compared with the traditional injection method, the analytical time for compounds in sulfur metabolism was reduced to 4 min/sample, the method throughput was enhanced five times, and the sensitivity was increased 14.4–33.1 times. Customized injection sequences were applied in experimental optimization. The developed method simplified the experimental optimization to one injection and is suitable for the analysis of sulfur metabolites in biological samples and has high sensitivity, throughput, speed, and accuracy.
Highlights
Sulfur-containing amino acids are important for maintaining cell balance and functions through regulation of cellular redox state and reactive oxygen species to eliminate free radicals and detoxify toxic compounds (Ward and DeNicola 2019; Rouhier et al 2015; Oliveira and Laurindo 2018; Turell et al 2013; Go and Jones 2013)
Multisegment injection based on hydrodynamic injection of multiple segments of sample that are spatially positioned between background electrolyte (BGE) in low pH
Because the multisegmented injection was performed by hydrodynamic injection of five sample segments that were spatially separated by BGE zones, five experimental points could be optimized simultaneously with the one injection, which dramatically reduced the experimental time
Summary
Sulfur-containing amino acids are important for maintaining cell balance and functions through regulation of cellular redox state and reactive oxygen species to eliminate free radicals and detoxify toxic compounds (Ward and DeNicola 2019; Rouhier et al 2015; Oliveira and Laurindo 2018; Turell et al 2013; Go and Jones 2013). Cysteine is transformed to cystine in neutral and basic conditions, accurate measurement of cellular thiol-containing amino acid concentrations is challenging because of interference (Comini 2016). Samples require pre-column derivatization and ion-exchange chromatography for detection. These steps lengthen the analysis time and limit the throughput. Sun et al developed a chemical derivatization method for LC-tandem MS (Sun et al 2016), but the separation time was 10 min and only five thiol compounds could be determined simultaneously
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
