Rationale: Stable isotope ratios can provide a 'fingerprint' to enable differentiation of sources of monofluoroacetate (MFA), hence providing a means to eliminate potential sources of MFA in a blackmail case involving the contamination of milk.
Methods: The stable isotopic compositions (δ H, δ C and δ O values) of a library of 43 samples of MFA were determined and multivariate models constructed to differentiate samples of different composition. The data from the MFA library were compared with those obtained from MFA extracted from contaminated milk powder (the case samples). The isotopic composition of the extracted samples was measured on dichloroaniline derivatives.
Results: A wide range of values was found for δ H, δ C and δ O of the MFA samples, much greater than the analytical repeatability between subsamples. Stable isotope data, therefore, provide a means of distinguishing samples of MFA. Of the 43 MFA samples tested, all but 6 could be eliminated as potential sources of the contamination, i.e. they had a distinctly different isotopic composition such that they must have had different histories and/or origins.
Conclusions: Stable isotope measurements of bulk and derivatized MFA provide an effective means of discriminating MFA samples. Three of the library samples that could not be differentiated from the case samples were directly connected to the suspect, and this evidence contributed to the suspect's admission of guilt.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1002/rcm.8416 | DOI Listing |
Food Chem
December 2024
Key Laboratory of Aquatic product, Ministry of Agriculture and Rural affairs, National R&D Center for Aquatic Product Processing, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou 510330, China; Key Laboratory of Efficient Utilization and Processing of Marine Fishery Resources of Hainan Province, Sanya Tropical Fisheries Research Institute, Sanya 572426, China.
The amino thiols are key antioxidants in organisms, and their detection in food is of significant importance. This study developed a new stable isotope chemical labelling coupled with ultra-performance liquid chromatography-tandem mass spectrometry method to detect six amino thiols from fish samples. By the proposed method, amino thiols were labeled after liquid extraction using the stable isotope labeling reagents of iodoacetamide (IAM) and D-IAM.
View Article and Find Full Text PDFInt J Biol Macromol
January 2025
Key Laboratory of Organosilicon Chemistry and Materials Technology, Ministry of Education; College of Materials Chemistry and Chemical Engineering, Hangzhou Normal University, Hangzhou, Zhejiang 311121, China. Electronic address:
Keto reductases are crucial NAD(P)H-dependent enzymes used for the enantioselective synthesis of alcohols from prochiral ketones. Typically, the NADPH cofactor is regenerated through a second enzyme and/or substrate. However, photocatalytic cofactor regeneration using water as a sacrificial electron and hydrogen donor presents a promising alternative, albeit a challenging one.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
January 2025
Cosmochemistry and Isotope Signatures Group Nuclear and Chemical Sciences Division Lawrence Livermore National Laboratory, Livermore, CA 94550.
The radiogenic isotopic compositions of basaltic Martian meteorites (shergottites) and clinopyroxene/olivine cumulate meteorites (nakhlite/chassignites) are used to define the global evolution of Mars. However, the two main groups of meteorites demonstrate that their sources underwent divergent styles of magmatic evolution. The shergottites portray a planet that differentiated ~4.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
January 2025
School of Physical Sciences, The Open University, Milton Keynes MK7 6AA, United Kingdom.
Much has been learned about Mars through data returned from space missions and analyses of martian meteorites. There are, however, many questions still outstanding which cannot currently be answered-including the issue of whether there is, or was, life on Mars. The return of a cache of samples-including of the atmosphere-from separate locations in Jezero Crater and with differing petrogeneses will provide the international community with the opportunity to explore part of the evolutionary history of Mars in great detail.
View Article and Find Full Text PDFCurr Res Food Sci
December 2024
Department of Chemical and Geological Sciences, University of Modena and Reggio Emilia, via G. Campi, 103, 41125 Modena, Italy.
Stable isotope analysis has become a valuable tool for studying food chain processes and verifying the authenticity and geographical origin of typical products. The analysis is particularly important for those foods with geographical indications, such as Aceto Balsamico Tradizionale di Modena labelled with the protected designation of origin mark (ABTM PDO) and Aceto Balsamico di Modena with the protected geographical indication (ABM PGI). Understanding how the aging process affects the isotopic composition of specific compounds in ABTM is important for distinguishing between traditional and non-traditional products, as well as for verifying their authenticity.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!