: Studies performed on heterogeneous reactions of hydroxyl radicals (OH) in aerosol materials of tropospheric interest are presented, focusing on the chemical ionization mass spectrometric approach. Kinetic investigations of these reactions reduced deviation in the estimation of OH concentration in the troposphere by atmospheric modeling from field measurements. Recently, OH uptake was investigated under wet conditions to acquire kinetic information under more realistic conditions repre-sentative of the troposphere. The information on the mechanism and kinetics of OH uptake by tropospheric aerosol materials will contribute to the updating of atmospheric models, allowing a better understanding of the troposphere.
{"title":"Application of Chemical Ionization Mass Spectrometry to Heterogeneous Reactions of OH with Aerosols of Tropospheric Interest","authors":"Jong-Ho Park","doi":"10.5478/MSL.2017.8.1.1","DOIUrl":"https://doi.org/10.5478/MSL.2017.8.1.1","url":null,"abstract":": Studies performed on heterogeneous reactions of hydroxyl radicals (OH) in aerosol materials of tropospheric interest are presented, focusing on the chemical ionization mass spectrometric approach. Kinetic investigations of these reactions reduced deviation in the estimation of OH concentration in the troposphere by atmospheric modeling from field measurements. Recently, OH uptake was investigated under wet conditions to acquire kinetic information under more realistic conditions repre-sentative of the troposphere. The information on the mechanism and kinetics of OH uptake by tropospheric aerosol materials will contribute to the updating of atmospheric models, allowing a better understanding of the troposphere.","PeriodicalId":18238,"journal":{"name":"Mass Spectrometry Letters","volume":"73 1","pages":"1-7"},"PeriodicalIF":0.5,"publicationDate":"2017-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86913785","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Analysis of quinidine for fish tissues using single drop microextraction (SDME) coupled with atmospheric pressure matrix assisted laser desorption/ionization mass spectrometry (AP-MALDI-MS) are reported. Optimization conditions; such as extraction solvent, extraction time, pH of the aqueous solution, salt additions (NaCl), stirring rate, matrix type and concentration are investigated. Linear dynamic range (μM), limit of detection, relative recovery%, and enrichment factor are 0.08-9.2, 0.05, 94.8±3.198.5±3.3%, 4.34±0.28-4.40±0.30, respectively. SDME-AP-MALDI-MS shows good intraday and interday reproducibility.
{"title":"Simple and Direct Quantitative Analysis for Quinidine Drug in Fish Tissues","authors":"Yuan-Chin Chen, H. Abdelhamid, Hui-Fen Wu","doi":"10.5478/MSL.2017.8.1.8","DOIUrl":"https://doi.org/10.5478/MSL.2017.8.1.8","url":null,"abstract":"Analysis of quinidine for fish tissues using single drop microextraction (SDME) coupled with atmospheric pressure matrix assisted laser desorption/ionization mass spectrometry (AP-MALDI-MS) are reported. Optimization conditions; such as extraction solvent, extraction time, pH of the aqueous solution, salt additions (NaCl), stirring rate, matrix type and concentration are investigated. Linear dynamic range (μM), limit of detection, relative recovery%, and enrichment factor are 0.08-9.2, 0.05, 94.8±3.198.5±3.3%, 4.34±0.28-4.40±0.30, respectively. SDME-AP-MALDI-MS shows good intraday and interday reproducibility.","PeriodicalId":18238,"journal":{"name":"Mass Spectrometry Letters","volume":"317 1","pages":"8-13"},"PeriodicalIF":0.5,"publicationDate":"2017-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89664177","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Products containing any one or more of 26 fragrance allergens likely to cause contact allergies, are required under the 2008 domestic cosmetic law to be labeled when their concentrations exceed a certain range. This study focuses on the comparison and development of analytical methods based on headspace-solid phase micro extraction (HS-SPME) and liquid-liquid extraction (LLE) methods followed by GC-MS/MS for 24 of the fragrance allergens excepting for two natural materials in water samples. Using the developed HS-SPME method, 15 of the 24 fragrance allergens were analyzed and 9 compounds which have relatively low logKOW values (below about 2.5) were not extracted, and the correlation coefficient (r2) of the calibration curve for quantification showed linearity of 0.9969 or more, and the method detection limits (MDL) and the limits of quantification (LOQ) were 0.078 ~ 0.582 μg/L and 0.261 ~ 1.940 μg/L, respectively. In the case of using the optimized LLE method, all 24 fragrance allergens were analyzed, and the correlation coefficient (r2) of the calibration curve for quantification showed linearity of 0.9957 or more, MDL and LOQ were 0.020 ~ 0.138 μg/L and 0.065 ~ 0.440 μg/L, respectively.
{"title":"Comparative Study of Extracting Fragrance Allergens by GC-MS/MS","authors":"I. Lee, J. Ahn, Bogsoon Kim, Deukmo Chung","doi":"10.5478/MSL.2017.8.1.18","DOIUrl":"https://doi.org/10.5478/MSL.2017.8.1.18","url":null,"abstract":"Products containing any one or more of 26 fragrance allergens likely to cause contact allergies, are required under the 2008 domestic cosmetic law to be labeled when their concentrations exceed a certain range. This study focuses on the comparison and development of analytical methods based on headspace-solid phase micro extraction (HS-SPME) and liquid-liquid extraction (LLE) methods followed by GC-MS/MS for 24 of the fragrance allergens excepting for two natural materials in water samples. Using the developed HS-SPME method, 15 of the 24 fragrance allergens were analyzed and 9 compounds which have relatively low logKOW values (below about 2.5) were not extracted, and the correlation coefficient (r2) of the calibration curve for quantification showed linearity of 0.9969 or more, and the method detection limits (MDL) and the limits of quantification (LOQ) were 0.078 ~ 0.582 μg/L and 0.261 ~ 1.940 μg/L, respectively. In the case of using the optimized LLE method, all 24 fragrance allergens were analyzed, and the correlation coefficient (r2) of the calibration curve for quantification showed linearity of 0.9957 or more, MDL and LOQ were 0.020 ~ 0.138 μg/L and 0.065 ~ 0.440 μg/L, respectively.","PeriodicalId":18238,"journal":{"name":"Mass Spectrometry Letters","volume":"40 1","pages":"18-22"},"PeriodicalIF":0.5,"publicationDate":"2017-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83823877","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The effect of cationization agent concentration on glycan detection via matrix-assisted laser desorption/ionization time-offlight mass spectrometry (MALDI-TOF MS) was investigated using Na+ ions in the form of NaCl as the cationization agent. NaCl solution concentrations ranging from 1 mM to 1 M were investigated. Glycans from ovalbumin were mixed with the cationization agent solution and the 2,5-dihydroxybenzoic acid (2,5-DHB) matrix solution in a volume ratio of 1:1:1. The resulting mixture was loaded onto the MALDI plate. Two MALDI-TOF MS instruments (Voyager DE-STR MALDI-TOF MS and Tinkerbell RT MALDITOF MS) were used for detection of glycans. The best detection, in terms of the number of identified glycans, the peak intensity, and the signal-to-noise (S/N) ratio, was obtained with NaCl concentrations of 0.01-0.1 M for both MALDI-TOF MS instruments.
{"title":"Effect of Cationization Agent Concentration on Glycan Detection Using MALDI TOF-MS","authors":"Inyoung Kim, Dongwon Shin, J. Paek, Jeongkwon Kim","doi":"10.5478/MSL.2017.8.1.14","DOIUrl":"https://doi.org/10.5478/MSL.2017.8.1.14","url":null,"abstract":"The effect of cationization agent concentration on glycan detection via matrix-assisted laser desorption/ionization time-offlight mass spectrometry (MALDI-TOF MS) was investigated using Na+ ions in the form of NaCl as the cationization agent. NaCl solution concentrations ranging from 1 mM to 1 M were investigated. Glycans from ovalbumin were mixed with the cationization agent solution and the 2,5-dihydroxybenzoic acid (2,5-DHB) matrix solution in a volume ratio of 1:1:1. The resulting mixture was loaded onto the MALDI plate. Two MALDI-TOF MS instruments (Voyager DE-STR MALDI-TOF MS and Tinkerbell RT MALDITOF MS) were used for detection of glycans. The best detection, in terms of the number of identified glycans, the peak intensity, and the signal-to-noise (S/N) ratio, was obtained with NaCl concentrations of 0.01-0.1 M for both MALDI-TOF MS instruments.","PeriodicalId":18238,"journal":{"name":"Mass Spectrometry Letters","volume":"05 1","pages":"14-17"},"PeriodicalIF":0.5,"publicationDate":"2017-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88268821","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Post-translational modifications (PTMs) of proteins regulate self-renewal and differentiation in embryonic stem cells (ESCs). Nitration of tyrosine residues of proteins in ESCs modulates their downstream pathways, which can affect self-renewal and differentiation. However, protein tyrosine nitration (PTN) in ESCs has been rarely studied. We reviewed 23 nitrated sites in stem cell proteins. Functional enrichment analysis showed that these nitrated proteins are involved in signal transduction, cell adhesion and migration, and cell proliferation in ESCs. Comparison between the nitrated and known phosphorylated sites revealed that 7 nitrated sites had overlapping phosphorylated sites, indicating functional links of PTNs to their associated signaling pathways in ESCs. Therefore, nitrated proteome provides a basis for understanding potential roles of PTN in self-renewal and differentiation of ESCs.
{"title":"Nitrated Proteome in Human Embryonic Stem Cells","authors":"J. Kang, D. Hwang, K. Kim","doi":"10.5478/MSL.2016.7.4.85","DOIUrl":"https://doi.org/10.5478/MSL.2016.7.4.85","url":null,"abstract":"Post-translational modifications (PTMs) of proteins regulate self-renewal and differentiation in embryonic stem cells (ESCs). Nitration of tyrosine residues of proteins in ESCs modulates their downstream pathways, which can affect self-renewal and differentiation. However, protein tyrosine nitration (PTN) in ESCs has been rarely studied. We reviewed 23 nitrated sites in stem cell proteins. Functional enrichment analysis showed that these nitrated proteins are involved in signal transduction, cell adhesion and migration, and cell proliferation in ESCs. Comparison between the nitrated and known phosphorylated sites revealed that 7 nitrated sites had overlapping phosphorylated sites, indicating functional links of PTNs to their associated signaling pathways in ESCs. Therefore, nitrated proteome provides a basis for understanding potential roles of PTN in self-renewal and differentiation of ESCs.","PeriodicalId":18238,"journal":{"name":"Mass Spectrometry Letters","volume":"43 1","pages":"85-90"},"PeriodicalIF":0.5,"publicationDate":"2016-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75731679","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2016-12-30DOI: 10.5478/MSL.2016.7.4.106
J. Jo, Riya Shrestha, Sangkyu Lee
: Ginseng, a traditional herbal drug, has been used in Eastern Asia for more than 2000 years. Various ginsenosides, which are the major bioactive components of ginseng products, have been shown to exert numerous beneficial effects on the human body when co-administered with drugs. However, this may give rise to ginsenoside-drug interactions, which is an important research consideration. In this study, acassette assay was performed the inhibitory effects of 12 ginsenosides on seven cytochrome P450 (CYP) isoforms in human liver microsomes (HLMs) using LC-MS/MS to predict the herb-drug interaction. After incubation of the 12 ginsenosides with seven cocktail CYP probes, the generated specific metabolites were quantified by LC-MS/MS to determine their activities. Ginsenoside Rb1 and F2 showed strong selective inhibitory effect on CYP2C9-cata-lyzed diclofenac 4′-hydroxylation and CYP2B6-catalyzed bupropion hydroxylation, respectively. Ginsenosides Rd showed weak inhibitory effect on the activities of CYP2B6, 2C9, 2C19, 2D6, 3A4, and compound K, while ginsenoside Rg3 showed weak inhibitory effects on CYP2B6. Other ginsenosides, Rc, Rf, Rg1, Rh1, Rf, and Re did not show significant inhibitory effects on the activities of the seven CYPs in HLM. Owing to the poor absorption of ginsenosides after oral administration in vivo , ginsenosides may not have significant side effects caused by interaction with other drugs.
{"title":"Inhibitory Effects of 12 Ginsenosides on the Activities of Seven Cytochromes P450 in Human Liver Microsomes","authors":"J. Jo, Riya Shrestha, Sangkyu Lee","doi":"10.5478/MSL.2016.7.4.106","DOIUrl":"https://doi.org/10.5478/MSL.2016.7.4.106","url":null,"abstract":": Ginseng, a traditional herbal drug, has been used in Eastern Asia for more than 2000 years. Various ginsenosides, which are the major bioactive components of ginseng products, have been shown to exert numerous beneficial effects on the human body when co-administered with drugs. However, this may give rise to ginsenoside-drug interactions, which is an important research consideration. In this study, acassette assay was performed the inhibitory effects of 12 ginsenosides on seven cytochrome P450 (CYP) isoforms in human liver microsomes (HLMs) using LC-MS/MS to predict the herb-drug interaction. After incubation of the 12 ginsenosides with seven cocktail CYP probes, the generated specific metabolites were quantified by LC-MS/MS to determine their activities. Ginsenoside Rb1 and F2 showed strong selective inhibitory effect on CYP2C9-cata-lyzed diclofenac 4′-hydroxylation and CYP2B6-catalyzed bupropion hydroxylation, respectively. Ginsenosides Rd showed weak inhibitory effect on the activities of CYP2B6, 2C9, 2C19, 2D6, 3A4, and compound K, while ginsenoside Rg3 showed weak inhibitory effects on CYP2B6. Other ginsenosides, Rc, Rf, Rg1, Rh1, Rf, and Re did not show significant inhibitory effects on the activities of the seven CYPs in HLM. Owing to the poor absorption of ginsenosides after oral administration in vivo , ginsenosides may not have significant side effects caused by interaction with other drugs.","PeriodicalId":18238,"journal":{"name":"Mass Spectrometry Letters","volume":"42 1","pages":"106-110"},"PeriodicalIF":0.5,"publicationDate":"2016-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90499110","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2016-12-30DOI: 10.5478/MSL.2016.7.4.000
Yong-Seok Kim, H. Min, Changmin Sung, Ju-Hyung Park, J. Son, K. Lee, H. Kim, Jaeick Lee, O. Kwon, Ki Hun Kim
: Glycerol was identified and isolated from endogenous interferences during analysis of human urine using high-reso-lution mass spectrometry (HRMS) for doping control. Urinary sample preparation was simple; the samples were diluted with an organic solvent and then analyzed using a liquid chromatography-mass spectrometry (“dilute and shoot” method). Although the interfering ion peaks were observed at the similar retention time of glycerol, the inference could be identified by isolation with HRMS and further investigation. Thus, creatinine was identified as the endogenous interference for glycerol analysis and it also caused ion suppression resulting in the decrease of glycerol signal. This study reports the first identification and efficient isolation of endogenous interferences in human urine for “dilute and shoot” method. The information about ion suppression could be novel to prevent overestimation or a false result for antidoping analysis.
{"title":"Analysis of Glycerol with Isolation of Endogenous Interferences using \"Dilute and Shoot\" Strategy and High-Resolution Mass Spectrometry in Human Urine for Antidoping Testing","authors":"Yong-Seok Kim, H. Min, Changmin Sung, Ju-Hyung Park, J. Son, K. Lee, H. Kim, Jaeick Lee, O. Kwon, Ki Hun Kim","doi":"10.5478/MSL.2016.7.4.000","DOIUrl":"https://doi.org/10.5478/MSL.2016.7.4.000","url":null,"abstract":": Glycerol was identified and isolated from endogenous interferences during analysis of human urine using high-reso-lution mass spectrometry (HRMS) for doping control. Urinary sample preparation was simple; the samples were diluted with an organic solvent and then analyzed using a liquid chromatography-mass spectrometry (“dilute and shoot” method). Although the interfering ion peaks were observed at the similar retention time of glycerol, the inference could be identified by isolation with HRMS and further investigation. Thus, creatinine was identified as the endogenous interference for glycerol analysis and it also caused ion suppression resulting in the decrease of glycerol signal. This study reports the first identification and efficient isolation of endogenous interferences in human urine for “dilute and shoot” method. The information about ion suppression could be novel to prevent overestimation or a false result for antidoping analysis.","PeriodicalId":18238,"journal":{"name":"Mass Spectrometry Letters","volume":"109 1","pages":"111-115"},"PeriodicalIF":0.5,"publicationDate":"2016-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74755279","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2016-12-30DOI: 10.5478/MSL.2016.7.4.102
Jong-Ho Park
This study explored the feasibility of using a carburization technique to enhance the ion intensity of isotopic analysis of ultra-trace levels of uranium using thermal ionization mass spectrometry (TIMS). Prior to fixing uranium samples on TIMS filaments, graphite powder suspended in nitric acid was deposited on rhenium filaments. We observed an enhancement of 238U+ intensity by a factor of two when carburization was used, and were able to roughly optimize the amount of graphite powder necessary for carburization. The positive shift in heating current when evaporating filaments upon carburization implies that uranium was chemically altered by carburization, when compared to normal fixation processes. The good agreement between our method and known standards down to an ultra-trace level shows that the proposed technique can be applied to isotopic uranium analysis down to abundances of ~10 pg.
{"title":"Feasibility of Using Graphite Powder to Enhance Uranium Ion Intensity in Thermal Ionization Mass Spectrometry (TIMS)","authors":"Jong-Ho Park","doi":"10.5478/MSL.2016.7.4.102","DOIUrl":"https://doi.org/10.5478/MSL.2016.7.4.102","url":null,"abstract":"This study explored the feasibility of using a carburization technique to enhance the ion intensity of isotopic analysis of ultra-trace levels of uranium using thermal ionization mass spectrometry (TIMS). Prior to fixing uranium samples on TIMS filaments, graphite powder suspended in nitric acid was deposited on rhenium filaments. We observed an enhancement of 238U+ intensity by a factor of two when carburization was used, and were able to roughly optimize the amount of graphite powder necessary for carburization. The positive shift in heating current when evaporating filaments upon carburization implies that uranium was chemically altered by carburization, when compared to normal fixation processes. The good agreement between our method and known standards down to an ultra-trace level shows that the proposed technique can be applied to isotopic uranium analysis down to abundances of ~10 pg.","PeriodicalId":18238,"journal":{"name":"Mass Spectrometry Letters","volume":"20 1","pages":"102-105"},"PeriodicalIF":0.5,"publicationDate":"2016-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80747688","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Collisional Activation Dissociation Mass Spectrometry Studies of Oligosaccharides Conjugated with Na+-Encapsulated Dibenzo-18-Crown-6 Ether","authors":"J. Bae, H. Song, Bongjin Moon, H. Oh","doi":"10.5478/MSL.2016.7.4.96","DOIUrl":"https://doi.org/10.5478/MSL.2016.7.4.96","url":null,"abstract":"","PeriodicalId":18238,"journal":{"name":"Mass Spectrometry Letters","volume":"104 1","pages":"96-101"},"PeriodicalIF":0.5,"publicationDate":"2016-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87797709","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In recent years, matrix-free laser desorption ionization (LDI) for mass spectrometry of thermally labile molecules has been an important research subject in the pursuit of new ionization methods to serve as alternatives to the conventional matrixassisted laser desorption ionization (MALDI) method. While many recent studies have reported successful LDI of thermally labile molecules from various surfaces, mostly from surfaces with nanostructures, understanding of what drives the LDI process still requires further study. This article briefly reviews the thermal aspects involved in the LDI mechanism, which can be characterized as rapid surface heating. The thermal mechanism was supported by observed LDI and postsource decay (PSD) of peptide ions produced from flat surfaces with special thermal properties including amorphous Si (a-Si) and tungsten silicide (WSix). In addition, the concept of rapid surface heating further suggests a practical strategy for the preparation of LDI sample plates, which allows us to choose various surface materials including crystalline Si (c-Si) and Au tailorable to specific applications.
{"title":"Rapid Surface Heating Promotes Laser Desorption Ionization of Thermally Labile Molecules from Surfaces","authors":"S. Han","doi":"10.5478/MSL.2016.7.4.91","DOIUrl":"https://doi.org/10.5478/MSL.2016.7.4.91","url":null,"abstract":"In recent years, matrix-free laser desorption ionization (LDI) for mass spectrometry of thermally labile molecules has been an important research subject in the pursuit of new ionization methods to serve as alternatives to the conventional matrixassisted laser desorption ionization (MALDI) method. While many recent studies have reported successful LDI of thermally labile molecules from various surfaces, mostly from surfaces with nanostructures, understanding of what drives the LDI process still requires further study. This article briefly reviews the thermal aspects involved in the LDI mechanism, which can be characterized as rapid surface heating. The thermal mechanism was supported by observed LDI and postsource decay (PSD) of peptide ions produced from flat surfaces with special thermal properties including amorphous Si (a-Si) and tungsten silicide (WSix). In addition, the concept of rapid surface heating further suggests a practical strategy for the preparation of LDI sample plates, which allows us to choose various surface materials including crystalline Si (c-Si) and Au tailorable to specific applications.","PeriodicalId":18238,"journal":{"name":"Mass Spectrometry Letters","volume":"54 1","pages":"91-95"},"PeriodicalIF":0.5,"publicationDate":"2016-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91037349","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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