Dong-Kyu Lee

Pralidoxime chloride, a highly hydrophilic antidote, cannot be effectively separated by reverse-phase high-performance liquid chromatography (RP-HPLC), unless the mobile-phase composition is varied. However, the use of ion-pairing reagents for pralidoxime separation is hindered by the persistent contamination of the stationary phase or chromatography system inside the HPLC system. Thus, this study aimed to develop a simple, rapid, and robust method based on RP-HPLC to determine pralidoxime chloride in antidote autoinjectors using a chaotropic salt as the mobile-phase additive. The use of UV detection at 270 nm allowed for the simultaneous detection of pralidoxime chloride and the internal standard, pyridine-2-aldoxime. The addition of chaotropic salts (NaPF6, NaBF4, and NaClO4) and an ionic liquid ([EMIM]PF6) increased the retention time of pralidoxime chloride. Among them, NaPF6 exhibited the highest capacity factor in the reverse-phase C18 column. Increasing the salt concentration increased the capacity factor and the number of theoretical plates. Analytical method validation was performed to assess the linearity, accuracy, precision, recovery, and repeatability, according to the Ministry of Food and Drug Safety guidelines. Additionally, this newly developed method exhibits an adequate separation capability, making it a potential substitute for the current method employed in the United States/Korean Pharmacopoeia, and it ensures the necessary durability to maintain the robustness and reliability of the analytical system.

Novel brominated flame retardants (NBFRs) are widely used to avoid environmental accumulation concerns and because of the regulations imposed on classical BFRs. However, recent studies have not revealed the negative effects of NBFR accumulation and exposure on humans. We conducted a metabolomics study on hexabromobenzene (HBB), one of the NBFRs, to investigate its effect on hepatocytes. Gas chromatography–mass spectrometry-based metabolite profiling was performed to observe metabolic perturbations by treating human livertissue-derived HepG2 cell lines with HBB for maximum 21 days. Metabolic pathway enrichment using 17 metabolite biomarkers determined via univariate and multivariate statistical analysis verified that long-term accumulation of HBB resulted in distinct diminution of eight amino acids and five other metabolites. Molecular docking of the biomarker-related enzymes revealed the potential molecular mechanism of hepatocellular response to HBB exposure, which disrupts the energy metabolism of hepatic cells. Collectively, this study may provide insights into the hidden toxicity of bioaccumulating HBB and unveil the risks associated with non-regulated NBFRs.