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Matrix effects can affect detection limits, precision, and accuracy and lead to signal enhancement or suppression effects in gas chromatography analysis. Analyte protectants, such as shikimic acid and gluconolactone, can imitate the effect of matrix components and reduce the differences in matrix effect between samples. This study aimed to investigate the ability of analyte protectants to enhance gas chromatography detector signals of different oxygenated-polycyclic aromatic hydrocarbons. Addition of 100 μg L shikimic acid and 200 μg L gluconolactone effectively enhanced detector response of the investigated target compounds. Addition of a higher content of analyte protectants did not result in any further enhancement. It was found that between four and eleven consecutive injections of a standard solution with analyte protectants were required to obtain a stable compound response. The long-term signal stability was then maintained with subsequent injections, though an overall negative drift of the system was observed over the sequence of 200 investigated injections. Analysis of the actual sample matrix instead of standards in pure solvent, as presented in this study, could also be a way to minimize the required number of injections. Shikimic acid and gluconolactone were first and foremost able to enhance signals of oxygenated-polycyclic aromatic hydrocarbons with similar functional groups (hydroxyl) in their molecular structure. It can be relevant to consider alternative analyte protectants with different functional groups according to the type of target compounds investigated.
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http://dx.doi.org/10.1016/j.talanta.2024.125810 | DOI Listing |
Arch Pharm (Weinheim)
September 2025
Department of Biology, Faculty of Arts and Sciences, Cukurova University, Adana, Turkey.
l-Ascorbic acid exhibits paradoxical behavior as both antioxidant and pro-oxidant in cancer treatment, with mechanisms and optimal dosing remaining unclear. This in vitro study investigated l-ascorbic acid's effects on healthy lymphocytes and HL-60 leukemia cells using concentrations of 0.5-2 mg/mL for 6 and 24 h.
View Article and Find Full Text PDFEnviron Int
September 2025
Center for Public Health Laboratory Service, Institute of Environmental Health, Wuhan Centers for Disease Prevention & Control, Wuhan, Hubei 430024, PR China. Electronic address:
Background: Studies suggest that phthalates (PAEs) may disrupt female reproductive health, but few have explored repeated measurements of PAE and their alternative exposure and their joint impact on reproductive outcomes.
Objectives: To evaluate the associations of repeatedly measured urinary levels of PAE and their alternative metabolites with reproductive outcomes in women receiving in vitro fertilization (IVF).
Methods: This study included 704 women undergoing IVF between February and October 2023 in Chongqing, China.
Gerontologist
September 2025
Department of Child Development and Family Studies, College of Human Ecology, Seoul National University, Seoul, South Korea.
Background And Objectives: Volunteering has cognitive benefits in later life and has been theorized to protect against Alzheimer's disease and related dementias (ADRD). A small but growing body of volunteer programs target people with mild cognitive impairment (MCI)-who are presumably at elevated risk for ADRD, but we know surprisingly little about who volunteers with MCI and how volunteering affects their subsequent cognitive changes. The current study sought to address these gaps.
View Article and Find Full Text PDFJ Youth Adolesc
September 2025
University of California, Davis, CA, USA.
School interethnic climate has interpersonal and intrapersonal implications for adolescent development, but little is known of how it influences their psychological adjustment over time, let alone what drives this influence. This study examined whether two components of identity-school belonging perceptions and ethnic-racial identity beliefs-mediate the association between 10th grade perceptions of school interethnic climate and 12th grade psychological adjustment. The analytic sample includes 849 students (50% girls; 30% Latinx, 27% White, 16% Asian/Pacific Islander, 18% Multiethnic, 6% African American/Black, 3% Other).
View Article and Find Full Text PDFDrugs Aging
September 2025
Dalla Lana School of Public Health, University of Toronto, V1 06, 2075 Bayview Avenue, Toronto, ON, M4N 3M5, Canada.
Background And Objectives: Older adults living with dementia are a heterogeneous group, which can make studying optimal medication management challenging. Unsupervised machine learning is a group of computing methods that rely on unlabeled data-that is, where the algorithm itself is discovering patterns without the need for researchers to label the data with a known outcome. These methods may help us to better understand complex prescribing patterns in this population.
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