zldmЗаводская лаборатория. Диагностика материаловIndustrial laboratory. Diagnostics of materials1028-68612588-0187ООО «Издательство «ТЕСТ-ЗЛ»10.26896/1028-6861-2024-90-9-5-14zldm-2284Research ArticleАНАЛИЗ ВЕЩЕСТВАSUBSTANCES ANALYSISОпределение селена в полигетероатомных органических соединениях методом атомно-эмиссионной спектрометрии с микроволновой плазмойDetermination of selenium in polyheteroatomic organic compounds by microwave plasma atomic emission spectrometryПетраковаС. Ю.PetrakovaS. Yu.

Светлана Юрьевна Петракова

630090, г. Новосибирск, проспект Академика Лаврентьева, д. 9

Svetlana Yu. Petrakova

9, Akademika Lavrentieva prosp., Novosibirsk, 630090

ТиховаВ. Д.TikhovaV. D.

Вера Дмитриевна Тихова

630090, г. Новосибирск, проспект Академика Лаврентьева, д. 9

Vera D. Tikhova

9, Akademika Lavrentieva prosp., Novosibirsk, 630090

tikhova@nioch.nsc.ruНовосибирский институт органической химии им. Н. Н. Ворожцова СО РАНРоссияN. N. Vorozhtsov Novosibirsk Institute of Organic Chemistry, SB RASRussian Federation202421092024909514Copyright © Петракова С.Ю., Тихова В.Д., 20242024Петракова С.Ю., Тихова В.Д.Petrakova S.Y., Tikhova V.D.Данная работа распространяется под лицензией Creative Commons Attribution 4.0.This work is licensed under a Creative Commons Attribution 4.0 License.https://www.zldm.ru/jour/article/view/2284

Разработана методика определения селена как макроэлемента синтетических полигетероатомных органических соединений методом атомно-эмиссионной спектрометрии с микроволновой плазмой (МП-АЭС). В качестве объектов анализа в основном служили различные производные селенадиазола. Найдены оптимальные условия пробоподготовки и атомно-эмиссионного определения селена. Для минерализации исследуемых веществ использовали сжигание в колбе, наполненной кислородом, с добавкой нитрата калия, который улучшает процесс горения и препятствует образованию сажи. В качестве поглотительного раствора для продуктов сжигания использовали 0,1 М соляную кислоту. Отмечено, что перед началом измерений необходимо провести продувку монохроматора и оптимизировать давление в распылителе атомно-эмиссионного спектрометра. В полученных условиях оценены метрологические характеристики методики — пределы обнаружения и количественного определения селена (0,2 и 0,6 мг/л соответственно), внутрилабораторная прецизионность и правильность. По разработанной методике проанализировали 11 синтетических органических соединений с содержанием селена от 12 до 51 %, при этом абсолютная погрешность анализа не превышала 0,3 %, что соответствует требованиям к органическому элементному анализу.

Currently, the problem of selenium determination in various objects attracts a large number of scientists. Interest in this area is attributed to the biological importance of selenium, since it is both an important nutrient and has a toxic effect on the body, depending on its amount and the properties of the compounds in which it is contained. Checking the purity of selenium-containing organic compounds (both determination of impurities and analysis of the basic composition), which is carried out by methods of elemental analysis, is an important task, however, in modern literature there is lack of information regarding this problem. The purpose of the presented study is to develop a method for the determination of selenium in the basic composition of synthetic polyheteroatomic organic compounds by microwave plasma atomic emission spectrometry. Various selenodiazole derivatives were mainly used for analysis. Optimal conditions for sample preparation and atomic emission determination of the selenium content were specified. To mineralize the substances under study, oxygen flask combustion was used with the addition of potassium nitrate, which improves combustion and prevents the formation of soot. Hydrochloric acid at a concentration of 0.1 M was used as an absorption solution. It is noted that before measurements it is necessary to purge the monochromator and optimize the pressure in the atomic emission spectrometer nebulizer and optimize pressure in the atomizer. In addition, the number of replicates and sampling time were increased to optimize selenium measurement. Under specified conditions, the metrological characteristics of the technique were determined: the detection limit and quantitation limit, intra-laboratory precision and accuracy. Selenium was determined in 11 synthetic organic compounds with selenium content ranged from 12 to 51%. The error of the analysis did not exceed 0.3%, which meets the requirements of organic elemental analysis.

органический элементный анализопределениеселенатомно-эмиссионная спектрометрия с микроволновой плазмойметод Шенигераorganic elemental analysisseleniumdeterminationmicrowave plasma atomic emission spectrometrySchöniger methodReferencesSong J., Zheng R., Yang R., et al. Species selective concentration and determination of nano-selenium and inorganic selenium species in environmental waters by micropore membrane filtration and ICP-MS / Anal. Bioanal. Chem. 2024. Vol. 416. N 13. P. 3271 – 3280. DOI: 10.1007/s00216-024-05278-wSong J., Zheng R., Yang R., et al. Species selective concentration and determination of nano-selenium and inorganic selenium species in environmental waters by micropore membrane filtration and ICP-MS / Anal. Bioanal. Chem. 2024. Vol. 416. N 13. P. 3271 – 3280. DOI: 10.1007/s00216-024-05278-wМихеев И. В., Карпухина Е. А., Усольцева Л. О. и др. Применение атомно-эмиссионной спектрометрии с микроволновой плазмой и генерацией гидридов для определения мышьяка и селена в минеральной воде / Заводская лаборатория. Диагностика материалов. 2016. Т. 82. ¹ 6. С. 5 – 9.Mikheev I. V., Karpukhina E. A., Usoltseva L. O., et al. Application of atomic emission spectrometry with microwave plasma and hydride generation for the determination of arsenic and selenium in mineral water / Industr. Lab. Mater. Diagn. 2016. Vol. 82. N 6. P. 5 – 9 [in Russian].Altunay N., Elik A., Katin K. Optimization of vortex-assisted ionic liquid dispersive liquid-liquid microextraction by experimental design prior to hydride generation atomic absorption spectrometry for determination of selenium species in food, beverage and water samples / J. Food Compos. Anal. 2021. Vol. 99. 103871. DOI: 10.1016/j.jfca.2021.103871Altunay N., Elik A., Katin K. Optimization of vortex-assisted ionic liquid dispersive liquid-liquid microextraction by experimental design prior to hydride generation atomic absorption spectrometry for determination of selenium species in food, beverage and water samples / J. Food Compos. Anal. 2021. Vol. 99. 103871. DOI: 10.1016/j.jfca.2021.103871Musielak M., Musielak E., Sitko R. Ultrasensitive determination of selenium in food samples and its speciation in water and beverages using thiosemicarbazide-incorporated graphene and total-reflection X-ray fluorescence spectrometry / Food Chem. 2024. Vol. 439. 138156. DOI: 10.1016/j.foodchem.2023.138156Musielak M., Musielak E., Sitko R. Ultrasensitive determination of selenium in food samples and its speciation in water and beverages using thiosemicarbazide-incorporated graphene and total-reflection X-ray fluorescence spectrometry / Food Chem. 2024. Vol. 439. 138156. DOI: 10.1016/j.foodchem.2023.138156Atasoy M., Yildiz D., Kula İ. Determination and speciation of selenium in water samples collected from Muğla (Turkey) province by hydride generation atomic absorption spectrometry / J. Indian Chem. Soc. 2022. Vol. 99. N 7. 100511. DOI: 10.1016/j.jics.2022.100511Atasoy M., Yildiz D., Kula İ. Determination and speciation of selenium in water samples collected from Muğla (Turkey) province by hydride generation atomic absorption spectrometry / J. Indian Chem. Soc. 2022. Vol. 99. N 7. 100511. DOI: 10.1016/j.jics.2022.100511Wei H., Pan D., Cui Y., et al. Anodic stripping determination of selenium in seawater using an electrode modified with gold nanodendrites/perforated reduced graphene oxide / Int. J. Electrochem. Sci. 2020. Vol. 15. N 2. P. 1669 – 1680. DOI: 10.20964/2020.02.51Wei H., Pan D., Cui Y., et al. Anodic stripping determination of selenium in seawater using an electrode modified with gold nanodendrites/perforated reduced graphene oxide / Int. J. Electrochem. Sci. 2020. Vol. 15. N 2. P. 1669 – 1680. DOI: 10.20964/2020.02.51Agrawal K., Patel K. S., Shrivas K. Development of surfactant assisted spectrophotometric method for determination of selenium in waste water samples / J. Hazard. Mater. 2009. Vol. 161. N 2 – 3. P. 1245 – 1249. DOI: 10.1016/j.jhazmat.2008.04.082Agrawal K., Patel K. S., Shrivas K. Development of surfactant assisted spectrophotometric method for determination of selenium in waste water samples / J. Hazard. Mater. 2009. Vol. 161. N 2 – 3. P. 1245 – 1249. DOI: 10.1016/j.jhazmat.2008.04.082Palatnik J., Londonio A., Morzán E., et al. Sensitive method for total selenium determination in garlic and nuts by UV-photochemical vapor generation coupled to atomic absorption spectrometry using mild conditions / J. Food Compos. Anal. 2024. Vol. 125. 105765. DOI: 10.1016/j.jfca.2023.105765Palatnik J., Londonio A., Morzán E., et al. Sensitive method for total selenium determination in garlic and nuts by UV-photochemical vapor generation coupled to atomic absorption spectrometry using mild conditions / J. Food Compos. Anal. 2024. Vol. 125. 105765. DOI: 10.1016/j.jfca.2023.105765Tyburska A., Jankowski K. Determination of selenium in dietary supplements by optical emission spectrometry after alkaline dissolution and subsequent headspace solid phase microextraction / J. Pharm. Biomed. Anal. 2013. Vol. 74. P. 268 – 272. DOI: 10.1016/j.jpba.2012.11.011Tyburska A., Jankowski K. Determination of selenium in dietary supplements by optical emission spectrometry after alkaline dissolution and subsequent headspace solid phase microextraction / J. Pharm. Biomed. Anal. 2013. Vol. 74. P. 268 – 272. DOI: 10.1016/j.jpba.2012.11.011Švarc-Gajić J., Stojanović Z. Selenium determination in biscuits and pasta: Development of chronopotentiometric stripping determination by using a sulphide as an internal standard / Talanta. 2013. Vol. 115. P. 474 – 481. DOI: 10.1016/j.talanta.2013.06.005Švarc-Gajić J., Stojanović Z. Selenium determination in biscuits and pasta: Development of chronopotentiometric stripping determination by using a sulphide as an internal standard / Talanta. 2013. Vol. 115. P. 474 – 481. DOI: 10.1016/j.talanta.2013.06.005Shishov A., Krekhova F., Bulatov A. Deep eutectic solvent based on thymol and menthol for microextraction and sensitive UV-Vis determination of total selenium in eggs and chicken tissue / J. Food Compos. Anal. 2024. Vol. 126. 105875. DOI: 10.1016/j.jfca.2023.105875Shishov A., Krekhova F., Bulatov A. Deep eutectic solvent based on thymol and menthol for microextraction and sensitive UV-Vis determination of total selenium in eggs and chicken tissue / J. Food Compos. Anal. 2024. Vol. 126. 105875. DOI: 10.1016/j.jfca.2023.105875Botella M. B., Oviedo M. N., Pacheco P., Wuilloud R. G. Highly efficient natural deep eutectic solvent-based liquid-liquid microextraction and inductively coupled plasma mass spectrometry for selective determination of inorganic selenium species in nut samples / Spectrochim. Acta, Part B. 2024. Vol. 211. 106832. DOI: 10.1016/j.sab.2023.106832Botella M. B., Oviedo M. N., Pacheco P., Wuilloud R. G. Highly efficient natural deep eutectic solvent-based liquid-liquid microextraction and inductively coupled plasma mass spectrometry for selective determination of inorganic selenium species in nut samples / Spectrochim. Acta, Part B. 2024. Vol. 211. 106832. DOI: 10.1016/j.sab.2023.106832Atasoy M., Kula İ. Speciation and determination of inorganic selenium species in certain fish and food samples by gold-coated W-coil atom trap hydride generation atomic absorption spectrometry / Food Chem. 2022. Vol. 369. 130938. DOI: 10.1016/j.foodchem.2021.130938Atasoy M., Kula İ. Speciation and determination of inorganic selenium species in certain fish and food samples by gold-coated W-coil atom trap hydride generation atomic absorption spectrometry / Food Chem. 2022. Vol. 369. 130938. DOI: 10.1016/j.foodchem.2021.130938Martins F. C. O. L., De Souza D. Ultrasensitive determination of selenium in foodstuffs and beverages using an electroanalytical approach / Microchem. J. 2021. Vol. 164. 105996. DOI: 10.1016/j.microc.2021.105996Martins F. C. O. L., De Souza D. Ultrasensitive determination of selenium in foodstuffs and beverages using an electroanalytical approach / Microchem. J. 2021. Vol. 164. 105996. DOI: 10.1016/j.microc.2021.105996He X., Huangfu K., Zhao J., et al. An efficient and low-cost method for the determination of selenium in selenium-enriched tea by high-performance liquid chromatography coupled with 3,3’-Diaminobenzidine derivatization / Talanta. 2024. Vol. 268. N 1. 125335. DOI: 10.1016/j.talanta.2023.125335He X., Huangfu K., Zhao J., et al. An efficient and low-cost method for the determination of selenium in selenium-enriched tea by high-performance liquid chromatography coupled with 3,3’-Diaminobenzidine derivatization / Talanta. 2024. Vol. 268. N 1. 125335. DOI: 10.1016/j.talanta.2023.125335Антонова С. Г., Елесова Е. Е., Носкова Г. Н., Драчева Л. В. Содержание и определение селена в пищевых продуктах / Пищевая промышленность. 2009. ¹ 2. С. 8 – 10.Antonova S. G., Elesova E. E., Noskova G. N., Dracheva L. V. Content and determination of selenium in food products / Pishch. Prom. 2009. N 2. P. 8 – 10 [in Russian].Schmitz C., Grambusch I. M., Neutzling Lehn D., et al. A systematic review and meta-analysis of validated analytical techniques for the determination of total selenium in foods and beverages / Food Chem. 2023. Vol. 429. 136974. DOI: 10.1016/j.foodchem.2023.136974Schmitz C., Grambusch I. M., Neutzling Lehn D., et al. A systematic review and meta-analysis of validated analytical techniques for the determination of total selenium in foods and beverages / Food Chem. 2023. Vol. 429. 136974. DOI: 10.1016/j.foodchem.2023.136974Gómez-Nieto B., Gismera M. J., Sevilla M. T., Procopio R. J. Direct solid sampling of biological species for the rapid determination of selenium by high-resolution continuum source graphite furnace atomic absorption spectrometry / Anal. Chim. Acta. 2022. Vol. 1202. 339637. DOI: 10.1016/j.aca.2022.339637Gómez-Nieto B., Gismera M. J., Sevilla M. T., Procopio R. J. Direct solid sampling of biological species for the rapid determination of selenium by high-resolution continuum source graphite furnace atomic absorption spectrometry / Anal. Chim. Acta. 2022. Vol. 1202. 339637. DOI: 10.1016/j.aca.2022.339637Hildebrand J., Greiner A., Drexler H., Göen T. Determination of eleven small selenium species in human urine by chromatographic-coupled ICP-MS methods / J. Trace Elem. Med. Biol. 2020. Vol. 61. 126519. DOI: 10.1016/j.jtemb.2020.126519Hildebrand J., Greiner A., Drexler H., Göen T. Determination of eleven small selenium species in human urine by chromatographic-coupled ICP-MS methods / J. Trace Elem. Med. Biol. 2020. Vol. 61. 126519. DOI: 10.1016/j.jtemb.2020.126519Sihlahla M., Mpupa A., Sojka M., et al. Determination of selenium in cereal and biofortified samples by ICP-OES using an alcohol-based deep eutectic solvent in digestion procedure / Adv. Sample Prep. 2023. Vol. 8. 100092. DOI: 10.1016/j.sampre.2023.100092Sihlahla M., Mpupa A., Sojka M., et al. Determination of selenium in cereal and biofortified samples by ICP-OES using an alcohol-based deep eutectic solvent in digestion procedure / Adv. Sample Prep. 2023. Vol. 8. 100092. DOI: 10.1016/j.sampre.2023.100092Ермаков В. В., Тютиков С. Ф., Хушвахтова С. Д. и др. Особенности количественного определения селена в биоматериалах / Вест. Тюменского гос. ун-та. 2010. ¹ 3. С. 206 – 214.Ermakov V. V., Tyutikov S. F., Khushvakhtova S. D., et al. Features of the quantitative determination of selenium in biomaterials / Vestn. Tumen. Gos. Univ. 2010. N 3. P. 206 – 214 [in Russian].Wiesenhofer T., Francesconi K. A., Kuehnelt D. A time-efficient flow injection/ICPMS method for the direct determination of total selenium in human urine / Microchem. J. 2017. Vol. 130. P. 310 – 315. DOI: 10.1016/j.jtemb.2020.126519Wiesenhofer T., Francesconi K. A., Kuehnelt D. A time-efficient flow injection/ICPMS method for the direct determination of total selenium in human urine / Microchem. J. 2017. Vol. 130. P. 310 – 315. DOI: 10.1016/j.jtemb.2020.126519Белозерова А. А., Майорова А. В., Бардина М. Н. Изучение матричных помех при ИСП-АЭС определении селена и теллура в металлургических материалах / Заводская лаборатория. Диагностика материалов. 2023. Т. 89. № 5. С. 19 – 27. DOI: 10.26896/1028-6861-2023-89-5-19-27Belozerova A. A., Mayorova A. V., Bardina M. N. Study of matrix interference in the ICP-AES determination of selenium and tellurium in metallurgical materials / Industr. Lab. Mater. Diagn. 2023. Vol. 89. N 5. P. 19 – 27 [in Russian]. DOI: 10.26896/1028-6861-2023-89-5-19-27Филатова Д. Г., Архипенко А. А., Статкус М. А. и др. Сорбция As(III) и Se(IV) из водных растворов для определения методом рентгенофлуоресцентного анализа с полным внешним отражением / Заводская лаборатория. Диагностика материалов. 2021. Т. 87. № 8. С. 19 – 22. DOI: 10.26896/1028-6861-2021-87-8-19-22Filatova D. G., Arkhipenko A. A., Statkus M. A., et al. Sorption of As(III) and Se(IV) from aqueous solutions for determination by X-ray fluorescence analysis with total external reflection / Industr. Lab. Mater. Diagn. 2021. Vol. 87. N 8. P. 19 – 22 [in Russian]. DOI: 10.26896/1028-6861-2021-87-8-19-22Chulanova E. A., Radiush E. A., Shundrina I. K., et al. Lewis ambiphilicity of 1,2,5-chalcogenadiazoles for crystal engineering: Complexes with crown ethers / Cryst. Growth Des. 2020. Vol. 20. N 9. P. 5868 – 5879. DOI: 10.1021/acs.cgd.0c00536Chulanova E. A., Radiush E. A., Shundrina I. K., et al. Lewis ambiphilicity of 1,2,5-chalcogenadiazoles for crystal engineering: Complexes with crown ethers / Cryst. Growth Des. 2020. Vol. 20. N 9. P. 5868 – 5879. DOI: 10.1021/acs.cgd.0c00536Baldissera M. D., Souza C. F., da Silva A. S., et al. Diphenyl diselenide dietary supplementation alleviates behavior impairment and brain damage in grass carp (Ctenopharyngodon idella) exposed to methylmercury chloride / Comp. Biochem. Physiol., Part C. 2020. Vol. 229. 108674. DOI: 10.1016/j.cbpc.2019.108674Baldissera M. D., Souza C. F., da Silva A. S., et al. Diphenyl diselenide dietary supplementation alleviates behavior impairment and brain damage in grass carp (Ctenopharyngodon idella) exposed to methylmercury chloride / Comp. Biochem. Physiol., Part C. 2020. Vol. 229. 108674. DOI: 10.1016/j.cbpc.2019.108674Mitra R., Sridevi V. S., Somasundaram K., Samuelson A. G. Photophysical and Biological Studies with Organometallic Ruthenium Complexes of Selenodiazole Ligands / Proc. Natl. Acad. Sci., India, Sect. A. 2016. Vol. 86. N 4. P. 511 – 520. DOI: 10.1007/s40010-016-0292-yMitra R., Sridevi V. S., Somasundaram K., Samuelson A. G. Photophysical and Biological Studies with Organometallic Ruthenium Complexes of Selenodiazole Ligands / Proc. Natl. Acad. Sci., India, Sect. A. 2016. Vol. 86. N 4. P. 511 – 520. DOI: 10.1007/s40010-016-0292-yRakitin O. A., Zibarev A. V. Synthesis and Applications of 5-Membered Chalcogen-Nitrogen π-Heterocycles with Three Heteroatoms / Asian J. Org. Chem. 2018. Vol. 7. N 12. P. 2397 – 2416. DOI: 10.1002/ajoc.201800536Rakitin O. A., Zibarev A. V. Synthesis and Applications of 5-Membered Chalcogen-Nitrogen π-Heterocycles with Three Heteroatoms / Asian J. Org. Chem. 2018. Vol. 7. N 12. P. 2397 – 2416. DOI: 10.1002/ajoc.201800536Masson M. R. Determination of Selenium and Tellurium in Organic Compounds and Organic Materials-A Review / Microchim. Acta. 1976. Vol. 1. P. 419 – 439. DOI: 10.1007/bf01218274Masson M. R. Determination of Selenium and Tellurium in Organic Compounds and Organic Materials-A Review / Microchim. Acta. 1976. Vol. 1. P. 419 – 439. DOI: 10.1007/bf01218274Анисимова Г. Ф., Климова В. А. Определение селена в органических веществах / Журн. аналит. химии. 1977. Т. 32. № 1. С. 119 – 122.Anisimova G. F., Klimova V. A. Determination of selenium in organic substances / Zh. Anal. Khimii. 1977. Vol. 32. N 1. P. 119 – 122 [in Russian].Анисимова Г. Ф., Климова В. А. Кулонометрические методы одновременного микроопределения углерода, водорода и селена или углерода, селена и серы в органических соединениях / Журн. аналит. химии. 1982. Т. 37. № 6. С. 1100 – 1103.Anisimova G. F., Klimova V. A. Coulometric methods for simultaneous microdetermination of carbon, hydrogen and selenium or carbon, selenium and sulfur in organic compounds / Zh. Anal. Khimii. 1982. Vol. 37. N 6. P. 1100 – 1103 [in Russian].Алексеева Н. Н., Лелюх М. И., Арестова Г. С., Ширинкина Н. В. Одновременное определение углерода, водорода, селена и фосфора в соединениях, содержащих селенофосфорильную группу / Журн. аналит. химии. 1991. Т. 46. № 10. С. 2096 – 2098.Alekseeva N. N., Lelyukh M. I., Arestova G. S., Shirinkina N. V. Simultaneous determination of carbon, hydrogen, selenium and phosphorus in compounds containing a selenophosphoryl group / Zh. Anal. Khimii. 1991. Vol. 46. N 10. P. 2096 – 2098 [in Russian]Фадеева В. П., Панин Д. О., Никуличева О. Н., Тихова В. Д. Экстракционно-спектрофотометрическое определение селена в селенорганических соединениях ароматическими o-диаминами / Журн. аналит. химии. 2014. Т. 69. № 5. С. 481 – 486. DOI: 10.7868/S0044450214030037Fadeeva V. P., Panin D. O., Nikulicheva O. N., Tikhova V. D. Extraction-spectrophotometric determination of selenium in organoselenium compounds with aromatic o-diamines / Zh. Anal. Khimii. 2014. Vol. 69. N 5. P. 432 – 437. DOI: 10.1134/S1061934814030034Солдатова Ю. А., Недведцкая Г. Б. Спектрофотометрическое определение селена в органических препаратах / Результаты научных исследований: сб. статей Международной научно-практической конференции. Ч. 2. — Екатеринбург, 2015. С. 21 – 23.Soldatova Yu. A., Nedvedtskaya G. B. Spectrophotometric determination of selenium in organic preparations / Results of Scientific Research: Proc. of the International Scientific and Practical Conference. Part 2. — Yekaterinburg, 2015. P. 21 – 23 [in Russian].Isozmu A., Kudou S., Nagashima H., Okutani T. Determination of selenium in organic selenium compounds by ion chromatography / Bunseki Kagaku. 1999. Vol. 48. N 5. P. 491 – 497. DOI: 10.2116/bunsekikagaku.48.491Isozmu A., Kudou S., Nagashima H., Okutani T. Determination of selenium in organic selenium compounds by ion chromatography / Bunseki Kagaku. 1999. Vol. 48. N 5. P. 491 – 497. DOI: 10.2116/bunsekikagaku.48.491Kuveke R. E. H., Barwise L., Van Ingen Y., et al. An International Study Evaluating Elemental Analysis / ACS Cent. Sci. 2022. Vol. 8. N 7. P. 855 – 863. DOI: 10.1021/acscentsci.2c00325Kuveke R. E. H., Barwise L., Van Ingen Y., et al. An International Study Evaluating Elemental Analysis / ACS Cent. Sci. 2022. Vol. 8. N 7. P. 855 – 863. DOI: 10.1021/acscentsci.2c00325

The authors declare that there are no conflicts of interest present.