Camin, F., Besic, D., Brewer, P., Allison, C., Coplen, T., Dunn, P., Gehre, M., Gröning, M., Meijer, H.-A.-J, Hélie, J.-F., Iacumin, P., Kraft, R., Krajnc, B., Kümmel, S., Lee, S., Meija, J., Mester, Z., Mohn, J., Moossen, H., Qi, H., Skrzypek, G., Sperlich, P., Viallon, J., Wassenaar, L. and Wielgosz, R. (2025). Stable Isotope Reference Materials and Scale Definitions—Outcomes of the 2024 IAEA Experts Meeting. Rapid Commun Mass Spectrom, 39: e10018, https://doi.org/10.1002/rcm.10018.
We apologize for this error.
The CIAAW-IUPAC endorsed all isotope delta scale definitions appearing in Camin et al. (2025) and agreed to publish the current and all future updates and corrections to these definitions on its website (www.ciaaw.org).
Camin， F., Besic， D., Brewer， P., Allison， C., Coplen， T., Dunn， P., Gehre， M., Gröning， M., Meijer， H.-A。-J, hsamlie, j - f。， Iacumin， P., Kraft， R., Krajnc， B., k mmel， S., Lee， S., Meija， J., Mester， Z., Mohn， J., Moossen， H., Qi， H., Skrzypek， G., Sperlich， P., Viallon， J., Wassenaar， L.和Wielgosz， R.（2025）。稳定同位素标准物质和标度定义——2024年国际原子能机构专家会议成果。快速共质谱，39:e10018, https://doi.org/10.1002/rcm.10018。我们为这个错误道歉。CIAAW-IUPAC认可Camin et al.（2025）中出现的所有同位素三角洲尺度定义，并同意在其网站（www.ciaaw.org）上发布这些定义的当前和未来所有更新和更正。
{"title":"Correction to “Stable Isotope Reference Materials and Scale Definitions—Outcomes of the 2024 IAEA Experts Meeting”","authors":"","doi":"10.1002/rcm.70017","DOIUrl":"10.1002/rcm.70017","url":null,"abstract":"<p>\u0000 <span>Camin, F.</span>, <span>Besic, D.</span>, <span>Brewer, P.</span>, <span>Allison, C.</span>, <span>Coplen, T.</span>, <span>Dunn, P.</span>, <span>Gehre, M.</span>, <span>Gröning, M.</span>, <span>Meijer, H.-A.-J</span>, <span>Hélie, J.-F.</span>, <span>Iacumin, P.</span>, <span>Kraft, R.</span>, <span>Krajnc, B.</span>, <span>Kümmel, S.</span>, <span>Lee, S.</span>, <span>Meija, J.</span>, <span>Mester, Z.</span>, <span>Mohn, J.</span>, <span>Moossen, H.</span>, <span>Qi, H.</span>, <span>Skrzypek, G.</span>, <span>Sperlich, P.</span>, <span>Viallon, J.</span>, <span>Wassenaar, L.</span> and <span>Wielgosz, R.</span> (<span>2025</span>). <span>Stable Isotope Reference Materials and Scale Definitions—Outcomes of the 2024 IAEA Experts Meeting</span>. <i>Rapid Commun Mass Spectrom</i>, <span>39</span>: e10018, https://doi.org/10.1002/rcm.10018.\u0000 </p><p>We apologize for this error.</p><p>The CIAAW-IUPAC endorsed all isotope delta scale definitions appearing in Camin et al. (2025) and agreed to publish the current and all future updates and corrections to these definitions on its website (www.ciaaw.org).</p>","PeriodicalId":225,"journal":{"name":"Rapid Communications in Mass Spectrometry","volume":"40 5","pages":""},"PeriodicalIF":1.7,"publicationDate":"2025-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://analyticalsciencejournals.onlinelibrary.wiley.com/doi/epdf/10.1002/rcm.70017","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145792603","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Valentine Grimaudo, Andreas Riedo, Marek Tulej, Peter Wurz
Rationale
Laser ablation mass spectrometry provides fast and direct chemical information of solids with high spatial resolution without the need for complex sample preparation. It has been shown that reducing the laser pulse length below picoseconds improves the quantification of chemical composition measurements of solids. This study compares the impact on chemical quantification of applying femtosecond laser ablation from IR to UV wavelengths to a steel alloy sample from NIST.
Methods
A compact laser ablation ionisation mass spectrometer (LIMS), coupled to a fs laser ablation ion source with a fundamental laser wavelength of 775 nm, is used for the presented mass spectrometric results. The fundamental wavelength is frequency doubled or tripled to 387 and 258 nm, respectively. An extensive mass spectrometric campaign, comprising various laser pulse energies, was conducted using the NIST iron alloy standard reference material 664. The recorded element composition was compared with the NIST certified values.
Results
Chemical composition analysis demonstrated the presence of significant chemical inhomogeneity of the NIST reference samples at spatial scales of about 10 μm, particularly in Ti and S. Large deviations identified were avoided for the presented study. A score was calculated for each of the accumulated spectra, indicating how close the measured composition reflected the certified values. The results show only minor differences between the wavelengths applied for sufficiently high irradiances.
Conclusions
These studies conducted on steel alloy NIST SRM 664 demonstrate that the impact of laser wavelength on the quantification becomes only noticeable for low irradiances. At sufficiently high laser irradiances at around 3.1 TW/cm2 and beyond, comparable calibration coefficients can be observed.
{"title":"Wavelength Dependence of fs Laser Ablation Ionisation Mass Spectrometry: a Dedicated Study on NIST SRM 664","authors":"Valentine Grimaudo, Andreas Riedo, Marek Tulej, Peter Wurz","doi":"10.1002/rcm.70012","DOIUrl":"10.1002/rcm.70012","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Rationale</h3>\u0000 \u0000 <p>Laser ablation mass spectrometry provides fast and direct chemical information of solids with high spatial resolution without the need for complex sample preparation. It has been shown that reducing the laser pulse length below picoseconds improves the quantification of chemical composition measurements of solids. This study compares the impact on chemical quantification of applying femtosecond laser ablation from IR to UV wavelengths to a steel alloy sample from NIST.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>A compact laser ablation ionisation mass spectrometer (LIMS), coupled to a fs laser ablation ion source with a fundamental laser wavelength of 775 nm, is used for the presented mass spectrometric results. The fundamental wavelength is frequency doubled or tripled to 387 and 258 nm, respectively. An extensive mass spectrometric campaign, comprising various laser pulse energies, was conducted using the NIST iron alloy standard reference material 664. The recorded element composition was compared with the NIST certified values.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Chemical composition analysis demonstrated the presence of significant chemical inhomogeneity of the NIST reference samples at spatial scales of about 10 μm, particularly in Ti and S. Large deviations identified were avoided for the presented study. A score was calculated for each of the accumulated spectra, indicating how close the measured composition reflected the certified values. The results show only minor differences between the wavelengths applied for sufficiently high irradiances.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>These studies conducted on steel alloy NIST SRM 664 demonstrate that the impact of laser wavelength on the quantification becomes only noticeable for low irradiances. At sufficiently high laser irradiances at around 3.1 TW/cm<sup>2</sup> and beyond, comparable calibration coefficients can be observed.</p>\u0000 </section>\u0000 </div>","PeriodicalId":225,"journal":{"name":"Rapid Communications in Mass Spectrometry","volume":"40 5","pages":""},"PeriodicalIF":1.7,"publicationDate":"2025-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12707028/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145761765","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ansar Babu Palathinkal, S. Farook Basha, Saraswathy Laya, Jahfar Nalakath, O. K. Praseen, Rasheed Naduvilakkandy, Marina Joseph, Shantymol V. Jose
Rationale
The growing emergence of synthetic opioids in the nitazene subclass such as butonitazene poses a significant challenge for doping control and toxicological monitoring. Butonitazene is a highly potent synthetic opioid, structurally distinct from classical opioids; its potential misuse in competitive events such as horse and camel racing cannot be overlooked. The in vitro metabolism of butonitazene was studied using camel liver, and findings were compared with metabolic profiles obtained from Cunninghamella elegans.
Methods
In vitro metabolic studies of butonitazene were conducted using homogenized camel liver and the fungus Cunninghamella elegans. A liquid chromatography–high resolution mass spectrometry method was used to identify and characterize the metabolites of butonitazene. Extracted metabolites were analyzed on a Thermo Fisher Orbitrap Exploris LC–MS system, renowned for its high resolution and accurate mass detection.
Results
A total of 17 Phase I and one Phase II metabolites were identified. The Phase I metabolism primarily involved N-dealkylation, O-dealkylation, and hydroxylation, whereas the Phase II metabolite was formed through the sulfonation of a hydroxylated Phase I metabolite. These metabolites demonstrate substantial potential as biomarkers for the long-term detection of butonitazene in doping control analysis.
Conclusion
The study utilized advanced high-resolution LC–MS techniques in identifying and characterizing the in vitro metabolites of butonitazene in camels. Given its high potency and its potential for misuse in competitive events, the identified metabolites provide a foundation for effective doping control measures, further enhancing regulatory frameworks designed to protect animal welfare and uphold the integrity of the sport.
{"title":"A Comparative In Vitro Metabolic Study of Butonitazene Using Camel Liver and Fungus Cunninghamella elegans for Doping Control Applications","authors":"Ansar Babu Palathinkal, S. Farook Basha, Saraswathy Laya, Jahfar Nalakath, O. K. Praseen, Rasheed Naduvilakkandy, Marina Joseph, Shantymol V. Jose","doi":"10.1002/rcm.70005","DOIUrl":"https://doi.org/10.1002/rcm.70005","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Rationale</h3>\u0000 \u0000 <p>The growing emergence of synthetic opioids in the nitazene subclass such as butonitazene poses a significant challenge for doping control and toxicological monitoring. Butonitazene is a highly potent synthetic opioid, structurally distinct from classical opioids; its potential misuse in competitive events such as horse and camel racing cannot be overlooked. The in vitro metabolism of butonitazene was studied using camel liver, and findings were compared with metabolic profiles obtained from <i>Cunninghamella elegans</i>.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>In vitro metabolic studies of butonitazene were conducted using homogenized camel liver and the fungus <i>Cunninghamella elegans</i>. A liquid chromatography–high resolution mass spectrometry method was used to identify and characterize the metabolites of butonitazene. Extracted metabolites were analyzed on a Thermo Fisher Orbitrap Exploris LC–MS system, renowned for its high resolution and accurate mass detection.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>A total of 17 Phase I and one Phase II metabolites were identified. The Phase I metabolism primarily involved <i>N</i>-dealkylation, <i>O</i>-dealkylation, and hydroxylation, whereas the Phase II metabolite was formed through the sulfonation of a hydroxylated Phase I metabolite. These metabolites demonstrate substantial potential as biomarkers for the long-term detection of butonitazene in doping control analysis.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusion</h3>\u0000 \u0000 <p>The study utilized advanced high-resolution LC–MS techniques in identifying and characterizing the in vitro metabolites of butonitazene in camels. Given its high potency and its potential for misuse in competitive events, the identified metabolites provide a foundation for effective doping control measures, further enhancing regulatory frameworks designed to protect animal welfare and uphold the integrity of the sport.</p>\u0000 </section>\u0000 </div>","PeriodicalId":225,"journal":{"name":"Rapid Communications in Mass Spectrometry","volume":"40 5","pages":""},"PeriodicalIF":1.7,"publicationDate":"2025-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145698873","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Atmospheric PM2.5 affects climate by altering radiative forcing and harms human health. Organosulfates (OSs) intensify these impacts, as cloud condensation nuclei modify the radiation balance and increase toxicological risks. We synthesized OSs reference standards and optimized a sensitive UPLC–MS/MS method, enabling precise quantification to mitigate PM2.5 pollution on climate and health.
Methods
We synthesized five organosulfates (ethyl-, 3-methylbenzyl-, cyclohexyl-, benzyl-, and phenethyl sulfate) as reference standards. These, combined with four commercial standards (methyl-, phenyl-, octyl-, and 4-nitrophenyl sulfate), were quantified by ultra-high performance liquid chromatography coupled with electrospray ionization (ESI) tandem mass spectrometry (UPLC-ESI-MS/MS). Separation used a Waters HSS T3 column with a gradient mobile phase (0.1% formic acid in H2O/CH3OH). ESI in negative mode enabled sensitive MS/MS detection.
Results
A nine-point calibration curve ranging from 0.08 to 20 ng mL−1 of standards in solvent was used to establish instrument response. The method was validated by analysis of three replicate environmental samples fortified with 5 ng mL−1 of mixed standard. The recoveries of various OSs were 44%–126%, and their method detection limits were 0.10 ng mL−1 and the method limits of quantification were 0.50 ng mL−1.
Conclusions
The optimized UPLC-ESI-MS/MS method was successfully applied for the determination of various OSs in PM2.5 collected from Tianjin, China. It enables the precise measurement of OSs in aerosols that provide a critical tool to improve air quality monitoring and develop strategies to reduce pollution-related health impacts.
大气PM2.5通过改变辐射强迫影响气候，危害人类健康。有机硫酸盐（OSs）加剧了这些影响，因为云凝结核改变了辐射平衡并增加了毒理学风险。我们综合了5种参考标准，并优化了一种灵敏的UPLC-MS /MS方法，实现了PM2.5的精确定量，从而减轻了PM2.5对气候和健康的影响。方法合成五种有机硫酸盐（乙基-、3-甲基苄基-、环己基-、苄基-和硫酸苯乙酯）作为参比标准。结合四种商业标准（甲基、苯基、辛基和4-硝基苯硫酸盐），采用超高效液相色谱-电喷雾电离（ESI）串联质谱（UPLC-ESI-MS/MS）进行定量。分离采用Waters HSS T3色谱柱，梯度流动相（0.1%甲酸水溶液/CH3OH）。ESI在阴性模式下使敏感的MS/MS检测。结果在0.08 ~ 20 ng mL−1的标准溶剂中建立9点校准曲线，建立仪器响应。通过分析添加5 ng mL−1混合标准物的三个重复环境样品，验证了该方法。各os的加样回收率为44% ~ 126%，方法检出限为0.10 ng mL−1，定量限为0.50 ng mL−1。结论优化后的UPLC-ESI-MS/MS方法可用于天津地区PM2.5中各种os的测定。它能够精确测量气溶胶中的生态系统，为改善空气质量监测和制定减少与污染有关的健康影响的战略提供重要工具。
{"title":"Synthesis of Reference Standards and Optimization of UPLC-ESI-MS/MS Method for Quantification of Organosulfates in PM2.5","authors":"Zhichao Dong, Subba Rao Devineni, Xiaoli Fu, Zhanjie Xu, Mingyu Li, Pingqing Fu, Cong-Qiang Liu, Chandra Mouli Pavuluri","doi":"10.1002/rcm.70008","DOIUrl":"https://doi.org/10.1002/rcm.70008","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Rationale</h3>\u0000 \u0000 <p>Atmospheric PM<sub>2.5</sub> affects climate by altering radiative forcing and harms human health. Organosulfates (OSs) intensify these impacts, as cloud condensation nuclei modify the radiation balance and increase toxicological risks. We synthesized OSs reference standards and optimized a sensitive UPLC–MS/MS method, enabling precise quantification to mitigate PM<sub>2.5</sub> pollution on climate and health.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>We synthesized five organosulfates (ethyl-, 3-methylbenzyl-, cyclohexyl-, benzyl-, and phenethyl sulfate) as reference standards. These, combined with four commercial standards (methyl-, phenyl-, octyl-, and 4-nitrophenyl sulfate), were quantified by ultra-high performance liquid chromatography coupled with electrospray ionization (ESI) tandem mass spectrometry (UPLC-ESI-MS/MS). Separation used a Waters HSS T3 column with a gradient mobile phase (0.1% formic acid in H<sub>2</sub>O/CH<sub>3</sub>OH). ESI in negative mode enabled sensitive MS/MS detection.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>A nine-point calibration curve ranging from 0.08 to 20 ng mL<sup>−1</sup> of standards in solvent was used to establish instrument response. The method was validated by analysis of three replicate environmental samples fortified with 5 ng mL<sup>−1</sup> of mixed standard. The recoveries of various OSs were 44%–126%, and their method detection limits were 0.10 ng mL<sup>−1</sup> and the method limits of quantification were 0.50 ng mL<sup>−1</sup>.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>The optimized UPLC-ESI-MS/MS method was successfully applied for the determination of various OSs in PM<sub>2.5</sub> collected from Tianjin, China. It enables the precise measurement of OSs in aerosols that provide a critical tool to improve air quality monitoring and develop strategies to reduce pollution-related health impacts.</p>\u0000 </section>\u0000 </div>","PeriodicalId":225,"journal":{"name":"Rapid Communications in Mass Spectrometry","volume":"40 5","pages":""},"PeriodicalIF":1.7,"publicationDate":"2025-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145698903","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Isomerism is common in new psychoactive substances (NPSs). Due to insignificant differences in their structure and properties, NPS isomers are hard to separate and identify, posing challenges for forensic laboratories to accurately identify them. Delta-8-tetrahydrocannabinol (Δ8-THC), a double-bond isomer of delta-9-tetrahydrocannabinol (Δ9-THC), is synthesized from cannabidiol (CBD).
Methods
To explore the MS fragmentation pattern of Δ8-THC and Δ9-THC, we systematically investigated them by gas chromatography–quadrupole time-of-flight mass spectrometry (GC-Q-TOF/MS) and liquid chromatography coupled to high-resolution quadrupole Orbitrap mass spectrometry (LC-Q-Orbitrap/MS).
Results
For GC-Q-TOF/MS analysis, significant differences in the ion abundance of the two characteristic ions at m/z 314 and 299 between these two isomers (Δ8-THC and Δ9-THC) stem from the varied stability of the free radicals they generate after losing an electron. Moreover, the ratio of the ion abundance of the fragment ions at m/z 314 and 299 can be utilized to recognize these two isomers. For LC-Q-Orbitrap/MS analysis, the fragmentation patterns of Δ8-THC were similar to those of Δ9-THC. Additional investigations by computational study revealed that Δ8-THC cationic radical can undergo a stepwise process like a retro Diels–Alder reaction to release an isoprene molecule directly but Δ9-THC via a double-hydrogen atoms transfer, shifting the location of carbon–carbon double bond, which indicates the different peaks at m/z 246 of Δ8-THC and 231 of Δ9-THC in EI-MS fragmentation processes.
Conclusions
Distinguishing accurately between Δ8-THC and Δ9-THC assists drug laboratories with in-depth analysis of drug sources, providing exact intelligence and scientific support to law enforcement.
{"title":"Differentiating Δ8-THC and Δ9-THC Isomers: Mass Spectrometry Analysis and Computational Explanation","authors":"Xing Ke, Xi Chen, Xianxin Chen, Hao Wu, Yilei Fan, Yu Xu, Jiawei Xu","doi":"10.1002/rcm.70011","DOIUrl":"https://doi.org/10.1002/rcm.70011","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Rationale</h3>\u0000 \u0000 <p>Isomerism is common in new psychoactive substances (NPSs). Due to insignificant differences in their structure and properties, NPS isomers are hard to separate and identify, posing challenges for forensic laboratories to accurately identify them. Delta-8-tetrahydrocannabinol (Δ<sup>8</sup>-THC), a double-bond isomer of delta-9-tetrahydrocannabinol (Δ<sup>9</sup>-THC), is synthesized from cannabidiol (CBD).</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>To explore the MS fragmentation pattern of Δ<sup>8</sup>-THC and Δ<sup>9</sup>-THC, we systematically investigated them by gas chromatography–quadrupole time-of-flight mass spectrometry (GC-Q-TOF/MS) and liquid chromatography coupled to high-resolution quadrupole Orbitrap mass spectrometry (LC-Q-Orbitrap/MS).</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>For GC-Q-TOF/MS analysis, significant differences in the ion abundance of the two characteristic ions at <i>m/z</i> 314 and 299 between these two isomers (Δ<sup>8</sup>-THC and Δ<sup>9</sup>-THC) stem from the varied stability of the free radicals they generate after losing an electron. Moreover, the ratio of the ion abundance of the fragment ions at <i>m/z</i> 314 and 299 can be utilized to recognize these two isomers. For LC-Q-Orbitrap/MS analysis, the fragmentation patterns of Δ<sup>8</sup>-THC were similar to those of Δ<sup>9</sup>-THC. Additional investigations by computational study revealed that Δ<sup>8</sup>-THC cationic radical can undergo a stepwise process like a retro Diels–Alder reaction to release an isoprene molecule directly but Δ<sup>9</sup>-THC via a double-hydrogen atoms transfer, shifting the location of carbon–carbon double bond, which indicates the different peaks at <i>m/z</i> 246 of Δ<sup>8</sup>-THC and 231 of Δ<sup>9</sup>-THC in EI-MS fragmentation processes.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>Distinguishing accurately between Δ<sup>8</sup>-THC and Δ<sup>9</sup>-THC assists drug laboratories with in-depth analysis of drug sources, providing exact intelligence and scientific support to law enforcement.</p>\u0000 </section>\u0000 </div>","PeriodicalId":225,"journal":{"name":"Rapid Communications in Mass Spectrometry","volume":"40 5","pages":""},"PeriodicalIF":1.7,"publicationDate":"2025-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145698847","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ying-Chun Chen, Han-Ju Chien, Yi-Feng Zheng, Huey-Ling Lin, Chien-Chen Lai
Rationale
Meta-topolin riboside (mTR) has shown superior effects over benzyladenine (BA) in promoting root and shoot development in passion fruit tissue culture, yet its underlying mechanisms remain unclear. Understanding the metabolic differences between mTR and BA treatments can inform optimized propagation strategies for high-quality planting material in this economically important crop.
Methods
Nodal buds of Passiflora edulis “Tainung No. 1” were cultured on BA- or mTR-supplemented medium, then analyzed using ultra-high-performance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry (UHPLC-QTOF-MS) in SWATH acquisition mode. Metabolite features were extracted, statistically filtered (VIP > 1, FC > 1.5 or < 0.667, p < 0.05), identified via multiple databases, and subjected to enrichment and pathway analysis.
Results
SWATH-MS detected 2823 ions in positive and 1637 in negative mode, with 21 significant metabolites identified in each mode. mTR treatment upregulated metabolites linked to root development (e.g., 5,10-methylenetetrahydrofolate, daidzin, and hesperidin) and stem elongation (amygdalin), while BA treatment had higher levels of kinetin, gibberellin A4, and lignans. Pathway analysis highlighted folate metabolism as significantly enriched in mTR samples.
Conclusions
mTR treatment altered phytohormone, flavonoid and phenolic profiles in ways that likely promote rooting, shoot elongation and oxidative stress resilience, explaining its superior growth performance over BA. These insights can guide refined cytokinin use in micropropagation and broader applications in horticultural biotechnology.
在百香果组织培养中，Meta-topolin riboside （mTR）在促进根和梢发育方面的作用优于苯ladenine (BA)，但其机制尚不清楚。了解mTR和BA处理之间的代谢差异可以为这种重要经济作物的优质种植材料的优化繁殖策略提供信息。方法将西番莲“台农1号”的节芽分别培养在BA-或mtr -补充培养基上，采用超高效液相色谱-四极杆飞行时间质谱（UHPLC-QTOF-MS） SWATH采集模式进行分析。提取代谢物特征，进行统计过滤（VIP > 1, FC >； 1.5或<； 0.667, p < 0.05），通过多个数据库进行鉴定，并进行富集和途径分析。结果SWATH-MS在阳性模式下检测到2823个离子，在阴性模式下检测到1637个离子，每种模式下鉴定出21种显著代谢物。mTR处理上调了与根发育相关的代谢物（例如，5,10-亚甲基四氢叶酸、大豆苷和橙皮苷）和茎伸长（苦杏仁苷），而BA处理具有更高水平的动蛋白、赤霉素A4和木脂素。途径分析显示，叶酸代谢在mTR样品中显著富集。结论mTR处理改变了植物激素、类黄酮和酚类物质的分布，可能促进了生根、芽伸长和氧化胁迫恢复能力，解释了其生长性能优于BA的原因。这些见解可以指导细胞分裂素在微繁殖中的精细使用以及在园艺生物技术中的更广泛应用。
{"title":"Comparative Metabolomic Analysis of Benzyl Adenine and Meta-Topolin Riboside Treatments in “Tainung No. 1” Passion Fruit","authors":"Ying-Chun Chen, Han-Ju Chien, Yi-Feng Zheng, Huey-Ling Lin, Chien-Chen Lai","doi":"10.1002/rcm.70006","DOIUrl":"https://doi.org/10.1002/rcm.70006","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Rationale</h3>\u0000 \u0000 <p><i>Meta</i>-topolin riboside (<i>m</i>TR) has shown superior effects over benzyladenine (BA) in promoting root and shoot development in passion fruit tissue culture, yet its underlying mechanisms remain unclear. Understanding the metabolic differences between <i>m</i>TR and BA treatments can inform optimized propagation strategies for high-quality planting material in this economically important crop.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>Nodal buds of <i>Passiflora edulis</i> “Tainung No. 1” were cultured on BA- or <i>m</i>TR-supplemented medium, then analyzed using ultra-high-performance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry (UHPLC-QTOF-MS) in SWATH acquisition mode. Metabolite features were extracted, statistically filtered (VIP > 1, FC > 1.5 or < 0.667, <i>p</i> < 0.05), identified via multiple databases, and subjected to enrichment and pathway analysis.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>SWATH-MS detected 2823 ions in positive and 1637 in negative mode, with 21 significant metabolites identified in each mode. <i>m</i>TR treatment upregulated metabolites linked to root development (e.g., 5,10-methylenetetrahydrofolate, daidzin, and hesperidin) and stem elongation (amygdalin), while BA treatment had higher levels of kinetin, gibberellin A4, and lignans. Pathway analysis highlighted folate metabolism as significantly enriched in <i>m</i>TR samples.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p><i>m</i>TR treatment altered phytohormone, flavonoid and phenolic profiles in ways that likely promote rooting, shoot elongation and oxidative stress resilience, explaining its superior growth performance over BA. These insights can guide refined cytokinin use in micropropagation and broader applications in horticultural biotechnology.</p>\u0000 </section>\u0000 </div>","PeriodicalId":225,"journal":{"name":"Rapid Communications in Mass Spectrometry","volume":"40 5","pages":""},"PeriodicalIF":1.7,"publicationDate":"2025-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145698887","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Time-of-flight secondary ion mass spectrometry (TOF-SIMS) is an ultrasensitive surface analysis technique capable of providing comprehensive elemental and molecular characterization of sample surfaces. The selection of appropriate sample preparation methods and optimal instrument parameters is critical for obtaining accurate and reliable analytical results.
Methods
This article systematically discusses three key aspects of the TOF-SIMS surface analytical technique: essential considerations in sample preparation, optimization of spectral acquisition parameters, and configuration of depth profiling parameters.
Results
Through representative case studies, we elucidate the fundamental principles and practical considerations for TOF-SIMS sample preparation and measurement optimization, thereby establishing a framework for acquiring high-quality TOF-SIMS data.
Conclusions
Sample preparation and processing are critical for ensuring the validity of TOF-SIMS detection results, while selecting appropriate testing parameters facilitates the acquisition of authentic and valid sample information. The presented methodology in this paper serves as a valuable reference for ensuring data reliability in TOF-SIMS analyses.
{"title":"Critical Considerations for TOF-SIMS Sample Preparation and Parameter Optimization","authors":"Chuqi Shi, Yanfang Pan, Qin Yang, Yikun Pan","doi":"10.1002/rcm.70010","DOIUrl":"https://doi.org/10.1002/rcm.70010","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Rationale</h3>\u0000 \u0000 <p>Time-of-flight secondary ion mass spectrometry (TOF-SIMS) is an ultrasensitive surface analysis technique capable of providing comprehensive elemental and molecular characterization of sample surfaces. The selection of appropriate sample preparation methods and optimal instrument parameters is critical for obtaining accurate and reliable analytical results.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>This article systematically discusses three key aspects of the TOF-SIMS surface analytical technique: essential considerations in sample preparation, optimization of spectral acquisition parameters, and configuration of depth profiling parameters.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Through representative case studies, we elucidate the fundamental principles and practical considerations for TOF-SIMS sample preparation and measurement optimization, thereby establishing a framework for acquiring high-quality TOF-SIMS data.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>Sample preparation and processing are critical for ensuring the validity of TOF-SIMS detection results, while selecting appropriate testing parameters facilitates the acquisition of authentic and valid sample information. The presented methodology in this paper serves as a valuable reference for ensuring data reliability in TOF-SIMS analyses.</p>\u0000 </section>\u0000 </div>","PeriodicalId":225,"journal":{"name":"Rapid Communications in Mass Spectrometry","volume":"40 5","pages":""},"PeriodicalIF":1.7,"publicationDate":"2025-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145698872","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Emma K. Hardwick, Alleigh N. Couch, J. Tyler Davidson
Rationale
Direct analysis in real time (DART) and electrospray ionization (ESI) are commonly used in forensic science and are combined with different activation techniques, which impact the degree and type of fragmentation. Therefore, this study compares collision-induced dissociation (CID), in-source CID (IS-CID), and all ions fragmentation (AIF) activation for nitazene analog identification using the NIST/NIJ Data Interpretation Tool (DIT).
Methods
DART and ESI were used to analyze 18 nitazene analogs on a quadrupole time-of-flight (Q-TOF) mass spectrometer. CID, IS-CID, and AIF were explored with DART, and CID was used for ESI analysis. All activation techniques included the use of low, medium, and high activation energies. The resulting data were compared with the NIST DART-MS Forensics Database using the NIST/NIJ DIT.
Results
The CID spectra were generally less noisy and had fewer ions than the IS-CID or the AIF spectra. The IS-CID spectra generated higher mass-to-charge (m/z) product ions and had fewer characteristic product ions than either CID or AIF. The NIST/NIJ DIT correctly identified 14/18 nitazene analogs when using AIF compared with 13/18 correct identifications using both CID and IS-CID. The ESI-CID data produced 12/18 correctly identified samples.
Conclusions
All three activation techniques performed similarly, based on the NIST/NIJ DIT results. However, IS-CID produced significantly less fragmentation than CID or AIF, indicating that AIF is a suitable screening technique for this instrumental setup. The NIST/NIJ DIT can also be utilized for ESI-CID spectra, although slightly fewer nitazene analogs were correctly identified with ESI-CID than with DART-CID.
{"title":"Comparison of Activation Techniques for the Identification of Nitazene Analogs Using the NIST/NIJ Data Interpretation Tool","authors":"Emma K. Hardwick, Alleigh N. Couch, J. Tyler Davidson","doi":"10.1002/rcm.70004","DOIUrl":"https://doi.org/10.1002/rcm.70004","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Rationale</h3>\u0000 \u0000 <p>Direct analysis in real time (DART) and electrospray ionization (ESI) are commonly used in forensic science and are combined with different activation techniques, which impact the degree and type of fragmentation. Therefore, this study compares collision-induced dissociation (CID), in-source CID (IS-CID), and all ions fragmentation (AIF) activation for nitazene analog identification using the NIST/NIJ Data Interpretation Tool (DIT).</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>DART and ESI were used to analyze 18 nitazene analogs on a quadrupole time-of-flight (Q-TOF) mass spectrometer. CID, IS-CID, and AIF were explored with DART, and CID was used for ESI analysis. All activation techniques included the use of low, medium, and high activation energies. The resulting data were compared with the NIST DART-MS Forensics Database using the NIST/NIJ DIT.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>The CID spectra were generally less noisy and had fewer ions than the IS-CID or the AIF spectra. The IS-CID spectra generated higher mass-to-charge (<i>m/z</i>) product ions and had fewer characteristic product ions than either CID or AIF. The NIST/NIJ DIT correctly identified 14/18 nitazene analogs when using AIF compared with 13/18 correct identifications using both CID and IS-CID. The ESI-CID data produced 12/18 correctly identified samples.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>All three activation techniques performed similarly, based on the NIST/NIJ DIT results. However, IS-CID produced significantly less fragmentation than CID or AIF, indicating that AIF is a suitable screening technique for this instrumental setup. The NIST/NIJ DIT can also be utilized for ESI-CID spectra, although slightly fewer nitazene analogs were correctly identified with ESI-CID than with DART-CID.</p>\u0000 </section>\u0000 </div>","PeriodicalId":225,"journal":{"name":"Rapid Communications in Mass Spectrometry","volume":"40 5","pages":""},"PeriodicalIF":1.7,"publicationDate":"2025-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145698902","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Heiko Moossen, Pharahilda M. Steur, Federica Camin, Bor Krajnc, Anett Enke, Heike Geilmann, Dipayan Paul, Markus Lange, Isabell von Rein, Harro A. J. Meijer
Rationale
In January 2024, the IAEA experts meeting endorsed both δ13C scales that are currently used within the scientific community: the Vienna Peedee belemnite (VPDB) δ13C scale defined by NBS 19 with a value of +1.95‰ exactly, and the VPDB-LSVEC scale defined by NBS 19 and the lithium carbonate LSVEC with a value of −46.60‰ exactly. Following the discovery of the instability of the LSVEC material, several expert laboratories independently proposed replacement reference materials (RMs). This study compares these calcium carbonate RMs IAEA-610, -611, -612, and USGS44 at the highest level of the metrological traceability chain and recommends values that enable users to realize the VPDB and VPDB-LSVEC scales.
Methods
The phosphoric acid reaction that is required to evolve CO2 from calcium carbonate RMs for isotope analyses is scrutinized by comparing the results of the different apparatuses used in the three participating laboratories. All three laboratories use high-precision dual-inlet isotope ratio mass spectrometers and assess the individual instrument offsets in terms of their effects on interlaboratory comparability of samples.
Results
The reported values for IAEA-610, -611, -612, and USGS44 on the δ13CVPDB scale are −9.114 ± 0.011‰, −30.815 ± 0.011‰, −36.739 ± 0.020‰, and −42.073 ± 0.015‰, respectively. Within their measurement uncertainty they are identical to previously published values. Finally, we provide values on the δ13CVPDB and δ13CVPDB-LSVEC scales for some RMs that are routinely used in elemental analysis–isotope ratio mass spectrometry.
{"title":"How Well Do We Know VPDB—Part 2: Interlaboratory Assessment of Existing δ13CVPDB Reference Materials","authors":"Heiko Moossen, Pharahilda M. Steur, Federica Camin, Bor Krajnc, Anett Enke, Heike Geilmann, Dipayan Paul, Markus Lange, Isabell von Rein, Harro A. J. Meijer","doi":"10.1002/rcm.10171","DOIUrl":"10.1002/rcm.10171","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Rationale</h3>\u0000 \u0000 <p>In January 2024, the IAEA experts meeting endorsed both <i>δ</i><sup>13</sup>C scales that are currently used within the scientific community: the Vienna Peedee belemnite (VPDB) <i>δ</i><sup>13</sup>C scale defined by NBS 19 with a value of +1.95‰ exactly, and the VPDB-LSVEC scale defined by NBS 19 and the lithium carbonate LSVEC with a value of −46.60‰ exactly. Following the discovery of the instability of the LSVEC material, several expert laboratories independently proposed replacement reference materials (RMs). This study compares these calcium carbonate RMs IAEA-610, -611, -612, and USGS44 at the highest level of the metrological traceability chain and recommends values that enable users to realize the VPDB and VPDB-LSVEC scales.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>The phosphoric acid reaction that is required to evolve CO<sub>2</sub> from calcium carbonate RMs for isotope analyses is scrutinized by comparing the results of the different apparatuses used in the three participating laboratories. All three laboratories use high-precision dual-inlet isotope ratio mass spectrometers and assess the individual instrument offsets in terms of their effects on interlaboratory comparability of samples.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>The reported values for IAEA-610, -611, -612, and USGS44 on the <i>δ</i><sup>13</sup>C<sub>VPDB</sub> scale are −9.114 ± 0.011‰, −30.815 ± 0.011‰, −36.739 ± 0.020‰, and −42.073 ± 0.015‰, respectively. Within their measurement uncertainty they are identical to previously published values. Finally, we provide values on the <i>δ</i><sup>13</sup>C<sub>VPDB</sub> and <i>δ</i><sup>13</sup>C<sub>VPDB-LSVEC</sub> scales for some RMs that are routinely used in elemental analysis–isotope ratio mass spectrometry.</p>\u0000 </section>\u0000 </div>","PeriodicalId":225,"journal":{"name":"Rapid Communications in Mass Spectrometry","volume":"40 4","pages":""},"PeriodicalIF":1.7,"publicationDate":"2025-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12676516/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145666528","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Guanglei Zhou, Lu Liu, Kuan Yan, Zhanliang Wang, Lisi Zhang
Rationale
Diuretics are banned in sports in- and out-of-competition without applicable threshold or reporting levels, and are classified as S5 Diuretics & Masking Agents by the World Anti-Doping Agency. In 2024, two cases reported by the Beijing Anti-Doping Laboratory involved the simultaneous detection of buthiazide and its degradation product, 4-amino-6-chloro-1,3-benzenedisulphonamide (ACB), in athlete urine samples. Subsequent investigations revealed that certain weight-loss medications contained undeclared buthiazide. While instability of thiazide diuretics such as hydrochlorothiazide and chlorothiazide in urine has been previously reported, the degradation behavior of structurally related compounds, buthiazide, mebutizide, and bemethizide, remains largely unexplored.
Methods
This study systematically evaluated the short-term stability of these three thiazide diuretics in human and artificial urine under various pH conditions (2.6, 5.0, 7.0, and 8.8), temperatures (−20°C, 25°C, 40°C, and 60°C), and light exposures (daylight and UV light). The degradation rate was evaluated using a single-point quantitative method by testing samples at predetermined time points in artificial urine (pH 5.0 and 7.0) at concentrations of 200, 1000, and 2000 ng/mL, and the results were subjected to statistical analysis. Long-term stability was evaluated after 1 week, 1 month, 3 months, and 6 months of storage at −20°C.
Results
Three thiazide diuretics and ACB were detected across all tested conditions, with higher degradation rates observed at higher pH values and temperatures. Single-point quantitative analysis corroborated that degradation was most rapid at 60°C, with mebutizide and bemethizide degrading faster than buthiazide. Long-term storage tests showed that buthiazide remained stable for 1 month at −20°C but partially degraded by 3 months, whereas mebutizide and bemethizide remained stable only for 1 week at low pH. Additionally, repeated freeze–thaw cycles promoted degradation in some samples.
Conclusions
These findings underscore the necessity of carefully controlled storage conditions in routine anti-doping analyses, especially when confirmatory testing of B samples is delayed.
{"title":"A Stability Study of Buthiazide, Mebutizide, and Bemethizide in Urinary and Aqueous Matrices","authors":"Guanglei Zhou, Lu Liu, Kuan Yan, Zhanliang Wang, Lisi Zhang","doi":"10.1002/rcm.70009","DOIUrl":"10.1002/rcm.70009","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Rationale</h3>\u0000 \u0000 <p>Diuretics are banned in sports in- and out-of-competition without applicable threshold or reporting levels, and are classified as S5 Diuretics & Masking Agents by the World Anti-Doping Agency. In 2024, two cases reported by the Beijing Anti-Doping Laboratory involved the simultaneous detection of buthiazide and its degradation product, 4-amino-6-chloro-1,3-benzenedisulphonamide (ACB), in athlete urine samples. Subsequent investigations revealed that certain weight-loss medications contained undeclared buthiazide. While instability of thiazide diuretics such as hydrochlorothiazide and chlorothiazide in urine has been previously reported, the degradation behavior of structurally related compounds, buthiazide, mebutizide, and bemethizide, remains largely unexplored.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>This study systematically evaluated the short-term stability of these three thiazide diuretics in human and artificial urine under various pH conditions (2.6, 5.0, 7.0, and 8.8), temperatures (−20°C, 25°C, 40°C, and 60°C), and light exposures (daylight and UV light). The degradation rate was evaluated using a single-point quantitative method by testing samples at predetermined time points in artificial urine (pH 5.0 and 7.0) at concentrations of 200, 1000, and 2000 ng/mL, and the results were subjected to statistical analysis. Long-term stability was evaluated after 1 week, 1 month, 3 months, and 6 months of storage at −20°C.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Three thiazide diuretics and ACB were detected across all tested conditions, with higher degradation rates observed at higher pH values and temperatures. Single-point quantitative analysis corroborated that degradation was most rapid at 60°C, with mebutizide and bemethizide degrading faster than buthiazide. Long-term storage tests showed that buthiazide remained stable for 1 month at −20°C but partially degraded by 3 months, whereas mebutizide and bemethizide remained stable only for 1 week at low pH. Additionally, repeated freeze–thaw cycles promoted degradation in some samples.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>These findings underscore the necessity of carefully controlled storage conditions in routine anti-doping analyses, especially when confirmatory testing of B samples is delayed.</p>\u0000 </section>\u0000 </div>","PeriodicalId":225,"journal":{"name":"Rapid Communications in Mass Spectrometry","volume":"40 4","pages":""},"PeriodicalIF":1.7,"publicationDate":"2025-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145666504","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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