The total N-nitroso content of foods can be measured by chemical denitrosation with hydrogen bromide and chemiluminescence detection of the cleaved nitric oxide radical. The denitrosation reagent itself causes a significant detector response which has limited the application of the technique to trace analysis. A procedure is described in which the errors associated with this interference are minimized. Application of this method to the trace analysis of aqueous and solid samples is reported together with an investigation of the effects of sample size on the accuracy and sensitivity of the assay as applied to aqueous analytes. The magnitude and significance of the false-positive response from nitrate is discussed in relation to the analysis of cured meats.
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http://dx.doi.org/10.1080/02652038409385850 | DOI Listing |
Toxics
September 2024
Epidemiology and Public Health Group, Division of Population Health, Health Services Research and Primary Care, School of Health Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester M13 9PL, UK.
Humans are unavoidably exposed to numerous different mutagenic DNA alkylating agents (AAs), but their role in the initiation of cancers is uncertain, in part due to difficulties in assessing human exposure. To address this, we have developed a screening method that measures promutagenic -alkylguanines (-AlkGs) in DNA and applied it to human DNA samples. The method exploits the ability of the alkyltransferase-like protein (Atl1) to recognise and bind to a wide range of -AlkGs in DNA.
View Article and Find Full Text PDFEnviron Sci Technol
September 2024
Department of Civil and Environmental Engineering, Syracuse University, 151 Link Hall, Syracuse, New York 13244, United States.
Monitoring the prevalence and persistence of -nitrosamines and their precursors in wastewater treatment plants (WWTPs) and effluent-receiving aquatic compartments is a priority for utilities practicing wastewater recycling or exploiting wastewater-impacted source waters. In this work, we developed an analytical framework that combines liquid chromatography-high-resolution mass spectrometry (LC-HRMS) with acidic triiodide-chemiluminescence analysis to characterize the composition and fate of total -nitrosamines (TONO) and their precursors along the treatment trains of eight WWTPs in New York. Through the parallel application of LC-HRMS and chemiluminescence methods, the TONO scores for 41 -nitrosamines containing structurally diverse substituents on their amine nitrogen were derived based on their solid-phase extraction recoveries and conversion efficiencies to nitric oxide.
View Article and Find Full Text PDFJ Agric Food Chem
August 2024
Department of Functional Biology, University of Oviedo, 33006 Oviedo, Spain.
Diet is one of the main exogenous sources of potentially carcinogenic nitrosamines (NAs) along with tobacco and cosmetics. Several factors can affect endogenous N-nitroso compounds (NOCs) formation and therefore the potential damage of the intestinal mucosa at initial colorectal cancer stages. To address this issue, 49 volunteers were recruited and classified according to histopathological analyses.
View Article and Find Full Text PDFNutrients
January 2024
Toxicogenomics Department, GROW School of Oncology & Reproduction, Faculty of Health, Medicine & Life Sciences, Maastricht University, 6211 LK Maastricht, The Netherlands.
The PHYTOME study investigated the effect of consuming processed meat products on outcomes related to colorectal cancer risk without testing the impact of genetic variability on these responses. This research aims to elucidate the genetic impact on apparent total N-nitroso compound (ATNC) excretion, colonic DNA adduct formation, ex vivo-induced DNA damage, and gene expression changes in colon biopsies of healthy participants. Through a systematic literature review, candidate polymorphisms were selected and then detected using TaqMan and PCR analysis.
View Article and Find Full Text PDFJ Expo Sci Environ Epidemiol
March 2024
Epidemiology Branch, National Institute of Environmental Health Sciences, NIH, Research Triangle Park, NC, USA.
Background: Nitrate and nitrite ingestion has been linked to kidney cancer, possibly via the endogenous formation of carcinogenic N-nitroso compounds. These exposures might also contribute to end-stage renal disease (ESRD).
Objectives: We investigated associations of drinking water nitrate and dietary nitrate and nitrite intakes (total and by food type) with incident ESRD in the Agricultural Health Study.
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