Yolanda Madrid

This is the 18th Atomic Spectrometry Update (ASU) to focus on advances in elemental speciation and covers a period of approximately 12 months from January 2025. This ASU review deals with all aspects of analytical atomic spectrometry speciation methods developed for: the determination of oxidation states; organometallic compounds; coordination compounds; metal- and heteroatom-containing biomolecules, including metalloproteins, proteins, peptides and amino acids; and the use of metal tagging to facilitate detection via atomic spectrometry. As with all ASU reviews, the focus of the research reviewed includes those methods that incorporate atomic spectrometry as the measurement technique, although molecular detection techniques are also included where they have provided a complementary approach to speciation analysis. The number of publications covered this year has fallen to the lowest number since this ASU has been published. However, there is still a good breadth of elements covered, with the most popular elements still being As, Hg and Se, and the focus of many papers is on elucidating mechanisms and transformation pathways, particularly in plants and animals/humans, rather than concentrating on the speciation method. A number of papers covering speciation analyses of elements related to nuclear power generation have been published, which reflects the increasing demand for this power source in the global efforts to decarbonise. There has also been a report on the use of XRF spectroscopy as a detector for LC and three papers of note that describe comprehensive methods for metallobiomolecules. Once again, the quality of the abstract for many of the papers is poor, with detail on the methodology, key results with data included, conclusions and implications thereof missing. This is likely to lead to fewer researchers reading the article or considering it for reviews such as those produced by the ASU.

This is the 17th Atomic Spectrometry Update (ASU) to focus on advances in elemental speciation and covers a period of approximately 12 months from January 2024. This ASU review deals with all aspects of analytical atomic spectrometry speciation methods developed for: the determination of oxidation states; organometallic compounds; coordination compounds; metal and heteroatom-containing biomolecules, including metalloproteins, proteins, peptides and amino acids; and the use of metal-tagging to facilitate detection via atomic spectrometry. As with all ASU reviews, the focus of the research reviewed includes those methods that incorporate atomic spectrometry as the measurement technique, although molecular detection techniques are also included where they have provided a complementary approach to speciation analysis. The number of publications covered this year has increased since last year but remains relatively low compared to many of the years that this ASU has been published for. However, there is a good breadth of elements covered, with the most popular elements still being As, Hg and Se, although there is little novelty in the analytical approaches employed, which reflects the maturity of elemental speciation analysis, and over 25 elements are covered in total, including a growing number of papers covering essential macro and trace elements, such as Fe and Mn and P, and S as a heteroatom in proteins. The advent of ICP-MS/MS instrumentation, allowing for the cost-effective quantification of S as SO at m/z 48, thus negating the ¹⁶O₂ interference is probably behind the rise in papers on this element once again, the quality of the abstract for many of the papers is poor, with details on the methodology, key results with data included, conclusions and implications thereof missing. This is likely to lead to fewer researchers reading the article or considering it for reviews such as those produced by the ASU.

Two potent antioxidants, selenoneine and ergothioneine, have been determined simultaneously for the first time in the muscle of highly consumed fish and in fish-derived products. The extraction methods were optimized, and their subsequent analysis was performed by HPLC-ESI-MS/MS. Best extraction efficiency (106 ± 3 and 104 ± 5%) was attained by performing a simple aqueous extraction containing 100 mmol L^-1 ammonium acetate or ammonium formate as extractants. Selenoneine and ergothioneine were simultaneously detected in tuna (0.306 ± 0.006 and 3.5 ± 0.2 μg g^-1) and swordfish (0.14 ± 0.02 and 1.1 ± 0.4 μg g^-1) muscle tissues, while in fish roe and in farmed salmon, only ergothioneine was detected (with contents ranging 0.03-3.3 μg g^-1). Moreover, the presence of their respective methylated forms was also considered. Additionally, Se-containing biomolecule profiles from water-soluble proteins were obtained by SEC-ICP-MS analysis. Results revealed similar profiles between fish and fish roe, whereas for ultraprocessed fish products, Se seems to be mostly associated with low-molecular-weight biomolecules. The results included in this work may contribute to a better understanding of the relations between selenoneine and ergothioneine in fishery products as well as their fate and potential modifications of Se-containing biomolecule profiles during fish processing.

This is the 16th Atomic Spectrometry Update (ASU) to focus on advances in elemental speciation and covers a period of approximately 12 months from January 2023. This ASU review deals with all aspects of the analytical atomic spectrometry speciation methods developed for: the determination of oxidation states; organometallic compounds; coordination compounds; metal and heteroatom-containing biomolecules, including metalloproteins, proteins, peptides and amino acids; and the use of metal-tagging to facilitate detection via atomic spectrometry. As with all ASU reviews the focus of the research reviewed includes those methods that incorporate atomic spectrometry as the measurement technique. However, because speciation analysis is inherently focused on the relationship between the metal(loid) atom and the organic moiety it is bound to, or incorporated within, atomic spectrometry alone cannot be the sole analytical approach of interest. For this reason, molecular detection techniques are also included where they have provided a complementary approach to speciation analysis. The number of publications covered this year has increased since last year but remains relatively low compared to many of the years that this ASU has been published for. However, there is a good breadth of elements covered, over 20 this year, with the most popular elements still being As, Hg and Se whilst Ge and Tc both make their first appearances this year. Another item to note is the decreasing quality of the abstract for many of the papers, with detail on the methodology, key results with data included, conclusions and implications thereof missing. This is likely to lead to fewer researchers reading the article.