A simple and efficient sequential electrokinetic and hydrodynamic injections in micellar electrokinetic chromatography method for quantification of anticancer drug 5-fluorouracil and its metabolite in human plasma

A simple and sensitive preconcentration strategy using sequential electrokinetic and hydrodynamic injection modes in micellar electrokinetic chromatography with diode array detection was developed and applied for the separation and determination of anticancer agent, 5-fluorouracil and its metabolite, 5-fluoro-2'-deoxyuridine, in human plasma. Sequential injection modes with increased analyte loading capacity using the anionic pseudo-stationary phase facilitated collection of the dispersed neutral and charged analytes into narrow zones and improved sensitivity. Several important parameters affecting sample enrichment performance were evaluated and optimized in this study. Under the optimized experimental conditions, 614- and 643-fold and 782- and 803-fold sensitivity improvement were obtained for 5-fluorouracil and its metabolite when compared with normal hydrodynamic and electrokinetic injection, respectively. The method has good linearity (1-1,000 ng/ml) with acceptable coefficient of determination (r2 > 0.993), low limits of detection (0.11-0.14 ng/ml) and satisfactory analyte relative recovery (97.4-99.7%) with relative standard deviations of 4.6-9.3% (n = 6). Validation results as well as the application to analysis of human plasma samples from cancer patients demonstrate the applicability of the proposed method to clinical studies

A simple and efficient sequential electrokinetic and hydrodynamic injections in micellar electrokinetic chromatography method for quantification of anticancer drug 5-fluorouracil and its metabolite in human plasma

A simple and sensitive preconcentration strategy using sequential electrokinetic and hydrodynamic injection modes in micellar electrokinetic chromatography with diode array detection was developed and applied for the separation and determination of anticancer agent, 5-fluorouracil and its metabolite, 5-fluoro-2'-deoxyuridine, in human plasma. Sequential injection modes with increased analyte loading capacity using the anionic pseudo-stationary phase facilitated collection of the dispersed neutral and charged analytes into narrow zones and improved sensitivity. Several important parameters affecting sample enrichment performance were evaluated and optimized in this study. Under the optimized experimental conditions, 614- and 643-fold and 782- and 803-fold sensitivity improvement were obtained for 5-fluorouracil and its metabolite when compared with normal hydrodynamic and electrokinetic injection, respectively. The method has good linearity (1–1,000 ng/ml) with acceptable coefficient of determination (r2 > 0.993), low limits of detection (0.11–0.14 ng/ml) and satisfactory analyte relative recovery (97.4–99.7%) with relative standard deviations of 4.6–9.3% (n = 6). Validation results as well as the application to analysis of human plasma samples from cancer patients demonstrate the applicability of the proposed method to clinical studies

Research progress on extraction and analytical methods for saxitoxin and its congeners

Saxitoxin is a potent neurotoxin commonly found in shellfish, produced by dinoflagellate and cyanobacterial blooms in seawater or fresh water. This review dissects the conventional liquid–liquid extraction (LLE) and solid-phase extraction (SPE) and the emerging microscale sample preparation method, followed by their achievements in the preconcentration of saxitoxin-group toxins from different matrices. Despite the tedious and multi-step procedures, LLE and SPE remain the most applied techniques in detecting saxitoxin due to their high sensitivity and selectivity. Nevertheless, microscale sample preparation offers potential as a green technique, especially in the development of advanced adsorbents for better sensitivity

Interpreting biomonitoring data: Introducing the international human biomonitoring (i-HBM) working group's health-based guidance value (HB2GV) dashboard.

Funding Information: The authors of this paper are members of the ISES i-HBM Working Group. The i-HBM is chaired by the National Institute of Environmental Health, Japan and co-chaired by Health Canada, and the group is comprised of an international assemblage with expertise in various aspects of biomonitoring (i-HBM members are co-authors of this paper or included in the Acknowledgments section). We would like to thank other Working Group members for their insights: Jillian Ashley-Martin, Ana Canas, André Conrad, Scott Hancock, Carin Huset, Tomohiko Isobe, Jung-Taek Kwon, Jueun Lee, Marc A. Nascarella, Andy Nong, Susana Pedraza-Diaz, Eva Sugeng, Natalie von Götz, Jiyoung Yoo. Publisher Copyright: © 2022Human biomonitoring (HBM) data measured in specific contexts or populations provide information for comparing population exposures. There are numerous health-based biomonitoring guidance values, but to locate these values, interested parties need to seek them out individually from publications, governmental reports, websites and other sources. Until now, there has been no central, international repository for this information. Thus, a tool is needed to help researchers, public health professionals, risk assessors, and regulatory decision makers to quickly locate relevant values on numerous environmental chemicals. A free, on-line repository for international health-based guidance values to facilitate the interpretation of HBM data is now available. The repository is referred to as the “Human Biomonitoring Health-Based Guidance Value (HB2GV) Dashboard”. The Dashboard represents the efforts of the International Human Biomonitoring Working Group (i-HBM), affiliated with the International Society of Exposure Science. The i-HBM's mission is to promote the use of population-level HBM data to inform public health decision-making by developing harmonized resources to facilitate the interpretation of HBM data in a health-based context. This paper describes the methods used to compile the human biomonitoring health-based guidance values, how the values can be accessed and used, and caveats with using the Dashboard for interpreting HBM data. To our knowledge, the HB2GV Dashboard is the first open-access, curated database of HBM guidance values developed for use in interpreting HBM data. This new resource can assist global HBM data users such as risk assessors, risk managers and biomonitoring programs with a readily available compilation of guidance values.publishersversionpublishe