1.Exercise improves microvascular function in patients with type 2 diabetes
Fan WEN ; Yang XIANG ; Huan ZHU ; Yanfang TUO ; Feng LI
Chinese Journal of Tissue Engineering Research 2026;30(5):1225-1235
BACKGROUND:Exercise is an effective way to improve microvascular function in patients with type 2 diabetes.In recent years,exercise has been used as an intervention therapy for microvascular dysfunction in patients with type 2 diabetes.However,few studies have systematically explored the influence of factors,such as"exercise type,exercise intensity and amount of exercise,"on microvascular function in patients.To some extent,this limits the formulation of precise exercise prescriptions to improve microvascular dysfunction in patients with type 2 diabetes and the comparison of study results.OBJECTIVE:To investigate the effects of exercise type,intensity,frequency and amount of exercise on microvascular function in patients with type 2 diabetes mellitus,and to make suggestions on exercise prescription.METHODS:The first author used computer to search the studies on the improvement of microvascular function in type 2 diabetes patients involving exercise in CNKI,WanFang,PubMed and other databases.The search terms were"diabetes mellitus,type 2 diabetes mellitus,microcirculation,microvascular reactivity,microvessels,capillaries,vasodilation,blood perfusion volume,endothelial cells,shear stress,exercise,aerobic exercise,resistance exercise,high-intensity exercise"in Chinese and English.The articles were screened by a quick glance at the article titles and abstracts to exclude those that were not closely related to the topic,and finally 60 articles were included for review.RESULTS AND CONCLUSION:(1)Exercise is an effective way to improve microvascular function in patients with type 2 diabetes.Aerobic exercise lasting 12-24 weeks,3-5 times/week,exercise time>30 minutes and intensity between 40%and 59%reserve oxygen intake can significantly improve microvascular function in patients with type 2 diabetes.On the basis of aerobic exercise,systemic resistance exercise 2-3 times a week(50%-85%1RM,every other day)or pressure resistance exercise can obtain better intervention effects.(2)In addition,exercise can improve microvascular function in patients with type 2 diabetes in a"dose-effect"manner,and patients can get better results from the intervention by increasing the amount of exercise,while maintaining safety.(3)The mechanism of exercise improving microvascular function in patients with type 2 diabetes is mainly related to promoting the release of nitric oxide and vascular endothelial growth factor from endothelial cells and inhibiting the release of endothelin1.
2.Exercise improves microvascular function in patients with type 2 diabetes
Fan WEN ; Yang XIANG ; Huan ZHU ; Yanfang TUO ; Feng LI
Chinese Journal of Tissue Engineering Research 2026;30(5):1225-1235
BACKGROUND:Exercise is an effective way to improve microvascular function in patients with type 2 diabetes.In recent years,exercise has been used as an intervention therapy for microvascular dysfunction in patients with type 2 diabetes.However,few studies have systematically explored the influence of factors,such as"exercise type,exercise intensity and amount of exercise,"on microvascular function in patients.To some extent,this limits the formulation of precise exercise prescriptions to improve microvascular dysfunction in patients with type 2 diabetes and the comparison of study results.OBJECTIVE:To investigate the effects of exercise type,intensity,frequency and amount of exercise on microvascular function in patients with type 2 diabetes mellitus,and to make suggestions on exercise prescription.METHODS:The first author used computer to search the studies on the improvement of microvascular function in type 2 diabetes patients involving exercise in CNKI,WanFang,PubMed and other databases.The search terms were"diabetes mellitus,type 2 diabetes mellitus,microcirculation,microvascular reactivity,microvessels,capillaries,vasodilation,blood perfusion volume,endothelial cells,shear stress,exercise,aerobic exercise,resistance exercise,high-intensity exercise"in Chinese and English.The articles were screened by a quick glance at the article titles and abstracts to exclude those that were not closely related to the topic,and finally 60 articles were included for review.RESULTS AND CONCLUSION:(1)Exercise is an effective way to improve microvascular function in patients with type 2 diabetes.Aerobic exercise lasting 12-24 weeks,3-5 times/week,exercise time>30 minutes and intensity between 40%and 59%reserve oxygen intake can significantly improve microvascular function in patients with type 2 diabetes.On the basis of aerobic exercise,systemic resistance exercise 2-3 times a week(50%-85%1RM,every other day)or pressure resistance exercise can obtain better intervention effects.(2)In addition,exercise can improve microvascular function in patients with type 2 diabetes in a"dose-effect"manner,and patients can get better results from the intervention by increasing the amount of exercise,while maintaining safety.(3)The mechanism of exercise improving microvascular function in patients with type 2 diabetes is mainly related to promoting the release of nitric oxide and vascular endothelial growth factor from endothelial cells and inhibiting the release of endothelin1.
3.Immunodynamic changes in a mouse model of malignant pleural effusion
Xiao-Lei WEI ; Xu GUO ; Chuang-Xin ZHANG ; Qi WANG ; Xiao-Fan LIU ; Ming-Ming SHAO ; Huan-Zhong SHI ; Kan ZHAI
Laboratory Animal Research 2026;42(1):59-67
Background:
Malignant pleural effusion (MPE), a common complication of advanced cancers, is associated with poor prognosis and reduced quality of life. Although host–tumor interactions are known to drive MPE development, the associated immune dynamics during disease progression remain unclear. Using a Lewis lung carcinoma-induced MPE model in C57BL/6JNidfc mice, we systematically evaluated general parameters and immune cell changes at two-day intervals throughout disease progression.
Results:
The day of Lewis lung carcinoma cell injection into the pleural space was designated as day 0. By day 10 post-injection (p.i.), MPE-bearing mice exhibited ~ 10% body weight loss, marking the experimental endpoint. Pleural tumor mass and pleural effusion volume were minimal up to day 4 p.i. but increased sharply from day 6 onward.CD45⁺ immune cell counts rose over time, and days 6, 8, and 10 p.i. marked key stages of MPE progression. On day 6, B cells, T cells, and natural killer cells, but not macrophages and neutrophils, increased significantly compared to earlier timepoints. By day 8, all immune cell subsets except T cells exceeded day 6 levels, and at day 10, natural killer cell numbers declined while others continued to increase. Besides, the numbers of CD8⁺ T cells, Th1 cells, regulatory T cells, and M2 macrophages progressively increased from day 6 to 10. Based on these data, days 6 and 10 were defined as early and advanced MPE stages, respectively, with distinct immune phenotypes. In advanced MPE, CD8⁺ T cells displayed reduced IFN-γ, TNF-α, Granzyme B, Perforin, FasL, and Ki-67, but upregulated PD-1 and CTLA-4 relative to early stage. Similarly, Th1 cells showed decreased IFN-γ, TNF-α, and IL-2 production along with reduced Ki-67 expression. Advanced-stage M2 macrophages exhibited lower MHC-II levels and impaired phagocytosis, but higher PD-L1 and IL-10 production, while neutrophils showed reduced TNF-α release and phagocytic activity.
Conclusions
Our findings characterize the temporal immune dynamics associated with MPE progression in a mouse model, revealing a transition from an early immunostimulatory state to a late immunosuppressive state. This study enhances our understanding of MPE immunopathogenesis and provides a foundation for developing precise, stagespecific therapeutic strategies.
4.Genetic diversity analysis of Aedes albopictus populations in Shandong Province using mitochondrial mtDNA-COⅠ gene sequences
Fan-jin MENG ; Yong LIU ; Huan HUANG ; Wei-bo MA ; Yi-fan WU ; Wei-long TAN
Acta Parasitologica et Medica Entomologica Sinica 2026;33(1):31-39
Objective This study aimed to investigate the genetic diversity, differentiation, and population structure of Aedes albopictus across different geographical regions in Shandong Province, and to explore the relationship between genetic diversity and geographical distribution. Methods Between July and August 2024, ten Ae. albopictus populations were sampled from seven cities in Shandong Province. Genomic DNA was extracted from individual mosquitoes, and the mitochondrial cytochrome c oxidase subunit I(COⅠ)gene was amplified using PCR and sequenced. The obtained sequences were verified using BLAST and analyzed with MAFFT, MEGA 11, DnaSP v6.12, Arlequin 3.5, PopART 1.7, STRUCTURE 2.3.4 and the R packages adegenet and vegan to assess genetic diversity and population structure. Results A total of 229 COⅠ sequences(662 bp) was obtained, revealing ten variable sites with no insertions or deletions. The overall base composition showed an AT bias of 67.7%. Haplotype analysis identified 11 haplotypes, with Hap2 being the dominant and most widely distributed haplotype across all populations. Neutrality tests showed significant population expansion only in the Rizhao population. Mantel testing result revealed that geographical distance does not significantly impede gene flow. Overall, genetic differentiation among populations was low, indicating frequent gene flow. When combined with additional samples from Shanghai, Fujian, Guangdong, Yunnan, Hainan and Guangxi, STRUCTURE, UPGMA and DAPC analyses revealed two primary genetic clusters of Ae. albopictus. Conclusions Ae. albopictus populations in Shandong Province exhibit frequent gene flow, low genetic differentiation, and relatively low overall genetic diversity. However, the Rizhao population showed signs of recent expansion, highlighting the need for enhanced surveillance and targeted control measures in this area.
5.Mechanism of Shengxian Yixin Granule (升陷益心颗粒) in the Treatment of Heart Failure with Preserved Ejection Fraction Based on Macrophage-Mediated Inflammatory Response
Zhengwei DONG ; Rui YU ; Qiaozhi LI ; Huan ZHAO ; Jingjing WEI ; Genhao FAN ; Xinlu WANG ; He WANG ; Yongxia WANG ; Mingjun ZHU
Journal of Traditional Chinese Medicine 2026;67(19):2086-2094
ObjectiveTo investigate the effect and mechanism of Shengxian Yixin Granule (升陷益心颗粒, SYG) in treating heart failure with preserved ejection fraction (HFpEF). MethodsExperiment 1: Forty male C57BL/6 mice were randomly divided into control group, model group, low-dose [25 mg/(kg·d)], medium-dose [50 mg/(kg·d)], and high-dose [(75 mg/(kg·d)] SYG groups, with 8 mice per group. Except for the control group, HFpEF was induced by a high-fat diet combined with Nω-nitro-L-arginine methyl ester in drinking water for 16 weeks. After 10 weeks of modeling, treatment groups received corresponding doses of SYG by gavage, while the control group and model group received equal volume of normal saline, for 6 weeks. After 6 weeks of administration, the body weight, blood pressure including systolic blood pressure (SBP) and diastolic blood pressure (DBP), and heart weight-to-tibia length ratio (HW/TL) were recorded. Echocardiography was used to evaluate left ventricular ejection fraction (LVEF) and the ratio of early to late diastolic transmitral flow velocity (E/A). Plasma N-terminal pro-brain natriuretic peptide (NT-proBNP) and C-reactive protein (CRP) levels were measured by ELISA. The expression level of brain natriuretic peptide (BNP) in heart tissue was detected by qRT-PCR. Blood lipid levels, including low-density lipoprotein cholesterol (LDL-C), triglycerides (TG), and total cholesterol (TC), were determined by a biochemical analyzer. Splenic proportions of M1 macrophages, M2 macrophages, T helper 17 (Th17) cells, and regulatory T (Treg) cells were analyzed by flow cytometry. Experiment 2: RAW 264.7 cells were stimulated with lipopolysaccharide (LPS) to establish an M1 macrophage polarization model, and then treated with SYG-containing serum for 24 h. The cells were divided into four groups, including blank serum group, high-dose SYG-containing serum group, LPS group, and LPS plus high-dose SYG-containing serum group. Combined with asignal transducer and activator of transcription 3 (Stat3) inhibitor for 24 h, the cells were divided into a lipopolysaccharide group, a high-dose SYG-containing serum group, an inhibitor group, and high-dose SYG-containing serum plus inhibitor group. The expression levels of inducible nitric oxide synthase (iNOS) and interleukin-1β (IL-1β) in each group were detected by qRT-PCR. The protein levels of iNOS, IL-1β, Stat3, and phosphorylated Stat3 (p-Stat3) were detected by Western Blotting. ResultsExperiment 1: Compared to the control group, the model group showed significantly decreased E/A ratio, and increased cardiac BNP expression, plasma NT-proBNP,HW/TL ratio, body weight, TC, LDL-C, SBP, and DBP, as well as shortened exhaustion distance and exhaustion time (P<0.05 or P<0.01). Compared to the model group, the E/A ratio increased in the low-, medium-, and high-dose SYG groups; cardiac BNP expression decreased in the low- and high-dose groups, and plasma NT-proBNP levels decreased in the high-dose group; the HW/TL ratio and body weight decreased, while exhaustion distance and exhaustion time increased in the medium- and high-dose groups; TG levels decreased in the low- and medium-dose groups, and LDL-C levels decreased in the medium- and high-dose groups; SBP and DBP decreased in the low-, medium-, and high-dose groups (P<0.05 or P<0.01). Compared to the low-dose SYG group, body weight decreased, and both exhaustion distance and exhaustion time increased in the medium- and high-dose groups (P<0.05 or P<0.01). Compared to the medium-dose SYG group, the exhaustion time increased in the high-dose SYG group (P<0.01). Experiment 2: In the LPS‑induced M1 macrophage polarization model, compared to the blank serum group, the LPS group showed significantly increased mRNA and protein expression of iNOS and IL‑1β, as well as the p‑Stat3/Stat3 ratio (P<0.01). Compared to the LPS group, the high‑dose SYG-containing serum plus LPS group showed significantly decreased mRNA and protein expression of iNOS and IL‑1β, as well as the p‑Stat3/Stat3 ratio (P<0.05 or P<0.01). Compared to the LPS group, the inhibitor group also showed significantly reduced these parameters (P<0.05 or P<0.01). ConclusionSYG can improve cardiac function, ventricular remodeling, exercise capacity, and lipid metabolism in HFpEF mice, while inhibiting inflammatory responses. Its mechanism may be related to the regulation of the Stat3 signaling pathway and inhibition of M1 macrophage polarization.
6.Mechanism of Shengxian Yixin Granule (升陷益心颗粒) in the Treatment of Heart Failure with Preserved Ejection Fraction Based on Macrophage-Mediated Inflammatory Response
Zhengwei DONG ; Rui YU ; Qiaozhi LI ; Huan ZHAO ; Jingjing WEI ; Genhao FAN ; Xinlu WANG ; He WANG ; Yongxia WANG ; Mingjun ZHU
Journal of Traditional Chinese Medicine 2026;67(19):2086-2094
ObjectiveTo investigate the effect and mechanism of Shengxian Yixin Granule (升陷益心颗粒, SYG) in treating heart failure with preserved ejection fraction (HFpEF). MethodsExperiment 1: Forty male C57BL/6 mice were randomly divided into control group, model group, low-dose [25 mg/(kg·d)], medium-dose [50 mg/(kg·d)], and high-dose [(75 mg/(kg·d)] SYG groups, with 8 mice per group. Except for the control group, HFpEF was induced by a high-fat diet combined with Nω-nitro-L-arginine methyl ester in drinking water for 16 weeks. After 10 weeks of modeling, treatment groups received corresponding doses of SYG by gavage, while the control group and model group received equal volume of normal saline, for 6 weeks. After 6 weeks of administration, the body weight, blood pressure including systolic blood pressure (SBP) and diastolic blood pressure (DBP), and heart weight-to-tibia length ratio (HW/TL) were recorded. Echocardiography was used to evaluate left ventricular ejection fraction (LVEF) and the ratio of early to late diastolic transmitral flow velocity (E/A). Plasma N-terminal pro-brain natriuretic peptide (NT-proBNP) and C-reactive protein (CRP) levels were measured by ELISA. The expression level of brain natriuretic peptide (BNP) in heart tissue was detected by qRT-PCR. Blood lipid levels, including low-density lipoprotein cholesterol (LDL-C), triglycerides (TG), and total cholesterol (TC), were determined by a biochemical analyzer. Splenic proportions of M1 macrophages, M2 macrophages, T helper 17 (Th17) cells, and regulatory T (Treg) cells were analyzed by flow cytometry. Experiment 2: RAW 264.7 cells were stimulated with lipopolysaccharide (LPS) to establish an M1 macrophage polarization model, and then treated with SYG-containing serum for 24 h. The cells were divided into four groups, including blank serum group, high-dose SYG-containing serum group, LPS group, and LPS plus high-dose SYG-containing serum group. Combined with asignal transducer and activator of transcription 3 (Stat3) inhibitor for 24 h, the cells were divided into a lipopolysaccharide group, a high-dose SYG-containing serum group, an inhibitor group, and high-dose SYG-containing serum plus inhibitor group. The expression levels of inducible nitric oxide synthase (iNOS) and interleukin-1β (IL-1β) in each group were detected by qRT-PCR. The protein levels of iNOS, IL-1β, Stat3, and phosphorylated Stat3 (p-Stat3) were detected by Western Blotting. ResultsExperiment 1: Compared to the control group, the model group showed significantly decreased E/A ratio, and increased cardiac BNP expression, plasma NT-proBNP,HW/TL ratio, body weight, TC, LDL-C, SBP, and DBP, as well as shortened exhaustion distance and exhaustion time (P<0.05 or P<0.01). Compared to the model group, the E/A ratio increased in the low-, medium-, and high-dose SYG groups; cardiac BNP expression decreased in the low- and high-dose groups, and plasma NT-proBNP levels decreased in the high-dose group; the HW/TL ratio and body weight decreased, while exhaustion distance and exhaustion time increased in the medium- and high-dose groups; TG levels decreased in the low- and medium-dose groups, and LDL-C levels decreased in the medium- and high-dose groups; SBP and DBP decreased in the low-, medium-, and high-dose groups (P<0.05 or P<0.01). Compared to the low-dose SYG group, body weight decreased, and both exhaustion distance and exhaustion time increased in the medium- and high-dose groups (P<0.05 or P<0.01). Compared to the medium-dose SYG group, the exhaustion time increased in the high-dose SYG group (P<0.01). Experiment 2: In the LPS‑induced M1 macrophage polarization model, compared to the blank serum group, the LPS group showed significantly increased mRNA and protein expression of iNOS and IL‑1β, as well as the p‑Stat3/Stat3 ratio (P<0.01). Compared to the LPS group, the high‑dose SYG-containing serum plus LPS group showed significantly decreased mRNA and protein expression of iNOS and IL‑1β, as well as the p‑Stat3/Stat3 ratio (P<0.05 or P<0.01). Compared to the LPS group, the inhibitor group also showed significantly reduced these parameters (P<0.05 or P<0.01). ConclusionSYG can improve cardiac function, ventricular remodeling, exercise capacity, and lipid metabolism in HFpEF mice, while inhibiting inflammatory responses. Its mechanism may be related to the regulation of the Stat3 signaling pathway and inhibition of M1 macrophage polarization.
7.Genetic diversity analysis of oxacillinase in 241 clinical isolates of Pseudomonas aeruginosa
Yuelong LI ; Jingyi ZHANG ; Yubing FU ; Meiqing SUN ; Beibei MIAO ; Xinyi GONG ; Xiao HAN ; Huan XING ; Pengfang GAO ; Jiachen LI ; Yating TANG ; Xinya FAN ; Yanlei GE ; Haijian ZHOU ; Juan LI ; Aiying DONG
Chinese Journal of Preventive Medicine 2025;59(7):1004-1012
Objective:To analyze the carriage status, subtype distribution and flanking gene sequence characteristics of oxacillinases (OXA enzyme) in 241 clinical strains of Pseudomonas aeruginosa, and assess their roles in the drug resistance of Pseudomonas aeruginosa and ability to horizontally transfer across species. Methods:Clinical P. aeruginosa isolates were collected from four hospitals in Sanya, Tangshan, Zhangjiakou, and Beijing. The prevalence of oxacillinases and their flanking gene sequences was analyzed by whole-genome sequencing (NGS) and bioinformatic approaches. Results:A total of 241 isolates of P. aeruginosa were gathered, and 35 blaOXA subtypes were identified through screening of 252 blaOXA genes. These genes were classified into three subfamilies: blaOXA-50-like (241, 95.6%), blaOXA-1-like (9, 3.6%) and blaOXA-10-like (2, 0.8%). Among these, 11 subtypes (11, 31.4%) were novel blaOXA subtypes. Nine of these belonged to the blaOXA-50-like subfamily and were designated as blaOXA-1244, blaOXA-1245, blaOXA-1246, blaOXA-1250, blaOXA-1252, blaOXA-1253, blaOXA-1254, blaOXA-1255, and blaOXA-1256. The remaining two belonged to the blaOXA-10-like subfamily and were named blaOXA-1247 and blaOXA-1248. Compared to the amino acid sequence of OXA-10, the newly identified subtype OXA-1247 exhibited a mutation at position 117, where a valine was replaced by a leucine. This change was thought to improve the enzyme′s ability to hydrolyze carbapenems. In the analysis of the flanking sequences of the blaOXA genes, Class I integrons were identified in four bacterial strains. The variable regions of these integrons carried three distinct patterns of resistance gene cassettes: aac( 6′) -Ib-blaOXA-1247-ant( 3′′) -Ia, aac( 6′) -Ib-blaOXA-1248 and aac( 6′) -Ib- blaIMP-45-blaOXA-1-catB3. Among these, the strain BJ2326 carried a class I integron that was connected to the downstream IS CR1 element to form a composite class I integron structure, additionally carrying the resistance gene blaPER-1. Out of the 223 non-wild-type P. aeruginosa strains, 127 strains exhibited non-wild-type profiles to the four beta-lactam antibiotics MEM, CAZ, FEP, and TZP, with the combination of MEM+CAZ+FEP being the most prevalent, representing 57.0% of the total. Conclusions:The blaOXA genes in 241 clinical P. aeruginosa strains showed diversity. Some blaOXA genes had a co-transfer risk with the metallo-β-lactamase resistance gene blaIMP-45. Among the 11 newly discovered blaOXA subtypes, the new subtype OXA-1247 may have carbapenemase activity and potential for horizontal transfer.
8.A Sensitive Ion Chromatography-Inductively Coupled Plasma Mass Spectrometry Method for Analysis of Iodine Speciation in Environmental Water Samples
Huan JIANG ; Ning CHEN ; Yan-Yun WANG ; Yu-Kun FAN ; Meng-Ting ZHANG ; Lu-Yuan ZHANG ; Xiao-Lin HOU
Chinese Journal of Analytical Chemistry 2025;53(2):278-288
Iodine speciations in aquatic environments are affected by dissolved oxygen,redox potential,microbial activity,organic matter decomposition,light reaction,etc.Accurate quantification of iodine speciation can not only help to understand the geochemical cycle of iodine,but also help to trace and study environmental processes.Based on the combination of ion chromatography(IC)and inductively coupled plasma mass spectrometry(ICP-MS),a rapid and sensitive method was established for determining the speciations of iodine in environmental water samples including seawater,river water,lake water,rainwater,groundwater,etc.The results presented here showed that IO3?and I?in seawater were quickly separated and measured within 120 s when using guard column AG22 and 8 mmol/L(NH4)2CO3 as the mobile phase.While for lake water,river water and precipitation samples with high soluble organically bond iodine(SOI),an AS22 separation column(250 mm×4 mm)connected with a guard column and using 50 mmol/L(NH4)2CO3 as mobile phase could effectively separate unknown SOI from IO3? to achieve accurate quantification of IO3?.For accurate correction of iodine measurement signal fluctuations,133Cs was directly added to the(NH4)2CO3 mobile phase as an internal standard.The SOI content was calculated by the total iodine concentrations minus the sum of IO3?and I?.The precision of the established iodine speciation analytical method was better than 3.5%,and the standard addition experiment showed that the analytical method was accurate.When the injection volume was 25 μL,the detection limits were 0.011?0.025 μg/L for IO3? and 0.023?0.031 μg/L for I?,respectively.The method was successfully used to analyze IO3?,SOI and I? in environmental water samples,such as seawater,river water,rainwater and groundwater.
9.Research and Application Progress of Polymer Magnetic Microspheres in the Fields of Biomedicine and Medical Diagnosis
Yong-Shuai TIAN ; Han WANG ; Fan YANG ; Jia-Nan LIU ; Huan-Lei WANG
Chinese Journal of Analytical Chemistry 2025;53(5):717-728
Polymer magnetic microspheres are a new type of composite functional materials,which have the advantages of stable structure,diverse modification methods,and magnetic response.These characteristics make polymer magnetic microspheres have the advantages of high sensitivity,high-specificity and fast response when detecting logo carriers or modified materials,and shows great application prospects in the fields of biomedicine and medical diagnosis.In this review,the basic properties of polymer magnetic microspheres were summarized,the research progresses of magnetic microspheres in the fields of biomedicine and medical diagnosis were emphatically introduced,and the improvement of preparation methods and development trends in the future were prospected.
10.Highly Sensitive Mass Spectrometric Analysis of Trace Iodine in Environmental Samples
Huan JIANG ; Yan-Yun WANG ; Yu-Kun FAN ; Ning CHEN ; Xiao-Lin HOU
Chinese Journal of Analytical Chemistry 2025;53(9):1536-1545
The cycling of iodine in the atmosphere and ocean plays a critical role in climate and environmental change.Ice cores and tree rings,as ideal climate archives,can provide essential data for paleoclimate reconstruction through accurate iodine analysis.However,iodine concentrations in ice core samples are as low as 0.01 μg/L,and as low as 0.01 μg/g in tree rings.Most currently reported analytical methods face challenges in accurately quantifying such low levels.In this study,a highly sensitive analytical method for trace iodine in environmental samples was developed based on inductively coupled plasma mass spectrometry(ICP-MS),incorporating a collision/reaction cell under the optimized collision/reaction gas conditions.Collision/reaction cell mode was employed to evaluate potential interferences in determination of trace iodine by ICP-MS.The results indicated that peak tailing from adjacent mass-to-charge ratios and polyatomic ion interferences could be considered negligible.However,residual iodine in ultrapure water constituted the major source of background,highlighting the need for strict control of sample pretreatment and procedural blanks in trace-level iodine analysis.By utilizing collision focusing effect of helium,the measurement sensitivity of iodine was enhanced to 3.5×105 cps(counts per second)/(μg/L),and the detection limit was reduced to 0.002 μg/L.The developed method exhibited a deviation of less than 2.3%in measurement of low-concentration standard solutions,indicating good accuracy.For actual samples and blanks,the precision of repeated measurements within 2 h was better than 1.6%,demonstrating excellent repeatability.No significant memory effect was observed during the measurements.The established method was successfully applied to determination of trace iodine in ice cores,tree rings,and other environmental samples,providing a robust technical foundation for investigating the role of iodine in climate and environmental change.


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