Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 14 de 14
Filtrar
1.
FASEB J ; 38(14): e23824, 2024 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-39012304

RESUMO

The regenerative ability of limb bones after injury decreases during aging, but whether a similar phenomenon occurs in jawbones and whether autophagy plays a role in this process remain unclear. Through retrospective analysis of clinical data and studies on a mouse model of jawbone defects, we confirmed the presence of delayed or impaired bone regeneration in the jawbones of old individuals and mice. Subsequently, osteoblasts (OBs) derived from mouse jawbones were isolated, showing reduced osteogenesis in senescent osteoblasts (S-OBs). We observed a reduction in autophagy within both aged jawbones and S-OBs. Additionally, pharmacological inhibition of autophagy in normal OBs (N-OBs) led to cell aging and decreased osteogenesis, while autophagic activation reversed the aging phenotype of S-OBs. The activator rapamycin (RAPA) increased the autophagy level and bone regeneration in aged jawbones. Finally, we found that fatty acid-binding protein 3 (FABP3) was degraded by autolysosomes through its interaction with sequestosome 1 (P62/SQSTM1). Autophagy inhibition within senescent jawbones and S-OBs led to the excessive accumulation of FABP3, and FABP3 knockdown partially rescued the decreased osteogenesis in S-OBs and alleviated age-related compromised jawbone regeneration. In summary, we confirmed that autophagy inhibition plays an important role in delaying bone regeneration in aging jawbones. Autophagic activation or FABP3 knockdown can partially rescue the osteogenesis of S-OBs and the regeneration of aging jawbones, providing insight into jawbone aging.


Assuntos
Envelhecimento , Autofagia , Regeneração Óssea , Proteínas de Ligação a Ácido Graxo , Osteoblastos , Osteogênese , Animais , Feminino , Humanos , Masculino , Camundongos , Envelhecimento/fisiologia , Envelhecimento/metabolismo , Autofagia/fisiologia , Senescência Celular/fisiologia , Proteínas de Ligação a Ácido Graxo/metabolismo , Proteínas de Ligação a Ácido Graxo/genética , Arcada Osseodentária , Camundongos Endogâmicos C57BL , Osteoblastos/metabolismo , Osteogênese/fisiologia
2.
Int J Clin Pract ; 2023: 2485368, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37313389

RESUMO

Background: The measurement and analysis of clinical crowns play a crucial role in stomatology, anthropology, and studies of genetic and environmental variables in oral and maxillofacial development. Purpose: The objective of the present study was to measure the parameters of clinical crowns of permanent dentition in youth of Han nationality using intraoral scanning and identify potential influencing factors. Materials and Methods: A total of 100 subjects (50 males and 50 females) of Han nationality aged 18-24 with normal occlusion were selected. An intraoral scanner was used to obtain the digital dental impressions, and Materialise Magics 21 software was used to measure the mesiodistal diameter (MDD), buccolingual diameter (BLD), height, mesiodistal angle (MDA), and vestibulo-oral angle (VOA) of clinical crowns. The central height was calculated based on the height of clinical crowns. SPSS 27.0 software was used for statistical analysis. The two-independent-samplet-test was used to assess discrepancies in clinical crowns between males and females. The paired t-test was used to determine differences between antimetric pairs of clinical crowns within the same arch. The repeatability of intraoral scanning was tested using the paired t-test between two measurements at one-month intervals. The overall estimated effect was considered significant where P < 0.05. Results: The MDD, BLD, height, MDA, and VOA of clinical crowns in the youth of Han nationality were measured, and the central height was calculated. No significant difference was found in terms of MDA and VOA between genders and antimetric pairs within the same arch. Regarding the distance parameters, the MDD, BLD, and height of clinical crowns in males were significantly larger than those in females (MDD: U1, U3, U7, L2, L3, L6, and L7: P < 0.01; BLD: U1: P=0.02; U3-U7 and L1-L7: P < 0.01; height: U2: P=0.03; and U1, U3-U7, and L3-L7: P < 0.01). No significant difference was found in clinical crowns between antimetric pairs within the same arch. Intraoral scanning demonstrated good repeatability in the measurement of clinical crowns. Conclusions: Apart from MDA and VOA, the parameters of clinical crowns in males were significantly larger than in females. Antimetric pairs of clinical crowns within the same arch demonstrated similar tooth dimensions. In future clinical practice and scientific research in the oral and maxillofacial region, a comprehensive design of sexual and ethnic characteristics should be considered.


Assuntos
Etnicidade , Projetos de Pesquisa , Adolescente , Humanos , Feminino , Masculino , Comportamento Sexual , Coroas
3.
BMC Oral Health ; 23(1): 470, 2023 07 10.
Artigo em Inglês | MEDLINE | ID: mdl-37424009

RESUMO

BACKGROUND: Within 3 years of the COVID-19 pandemic, increasing interest has been given to its potential influence on health status due to lockdowns caused by the pandemic. However, the impact is inadequately understood, especially for college students. This study aimed to investigate the potential association between psychological stress, anxiety and oral health of college students during the Omicron wave of the COVID-19 pandemic. METHODS: An online survey with measurements of psychological stress, anxiety and oral health was completed by 1770 Chinese college students. The Perceived Stress Scale-14 (PSS-14) and Generalized Anxiety Disorder-7 (GAD-7) were used to measure psychological stress and anxiety, respectively. Oral health status was self-reported including toothache, gingival bleeding, and oral ulcer. Multivariable logistic regressions were performed to determine underlying associations for outcome variables. Structural equation modeling (SEM) was performed to confirm the relationship between mental and oral health status. RESULTS: Of the 1770 subjects, 39.2% presented high psychological stress and only 41.2% expressed no anxiety. A significant association was found between psychological stress, anxiety and oral health status. Anxiety has significant impacts on toothache (OR = 0.36; 95%CI: 0.23-0.55; p < 0.01), gingival bleeding (OR = 0.43; 95%CI: 0.29-0.65; p < 0.01), and oral ulcer (OR = 0.54; 95%CI: 0.36-0.80; p < 0.01). Anxiety significantly mediated the association between psychological stress and self-reported oral symptoms. CONCLUSIONS: Anxiety may be a significant risk indicator for mental health among college students and demonstrates a significant relationship with the occurrence of self-reported oral symptoms. Concerns about academic and life changes caused by the pandemic were the two most significant sources of stress.


Assuntos
COVID-19 , Úlceras Orais , Humanos , Estudos Transversais , Saúde Bucal , Úlceras Orais/epidemiologia , Pandemias , Odontalgia , COVID-19/complicações , COVID-19/epidemiologia , Controle de Doenças Transmissíveis , Transtornos de Ansiedade , Estresse Psicológico/complicações , Estresse Psicológico/epidemiologia , Estudantes , Hemorragia Gengival , Depressão
4.
Heliyon ; 10(5): e26876, 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38434362

RESUMO

Background: With a wide range of dental implants currently used in clinical scenarios, evidence is limited on selecting the type of dental implant best suited to endure the biting force of missing teeth. Finite Element Analysis (FEA) is a reliable technology which has been applied in dental implantology to study the distribution of biomechanical stress within the bone and dental implants. Purpose: This study aimed to perform a systematic review to evaluate the biomechanical properties of dental implants regarding their length and diameter using FEA. Material and methods: A comprehensive search was performed in PubMed/MEDLINE, Scopus, Embase, and Web of Science for peer-reviewed studies published in English from October 2003 to October 2023. Data were organized based on the following topics: area, bone layers, type of bone, design of implant, implant material, diameter of implant, length of implant, stress units, type of loading, experimental validation, convergence analysis, boundary conditions, parts of Finite Element Model, stability factor, study variables, and main findings. The present study is registered in PROSPERO under number CRD42022382211. Results: The query yielded 852 results, of which 40 studies met the inclusion criteria and were selected in this study. The diameter and length of the dental implants were found to significantly influence the stress distribution in cortical and cancellous bone, respectively. Implant diameter was identified as a key factor in minimizing peri-implant stress concentrations and avoiding crestal overloading. In terms of stress reduction, implant length becomes increasingly important as bone density decreases. Conclusions: The diameter of dental implants is more important than implant length in reducing bone stress distribution and improving implant stability under both static and immediate loading conditions. Short implants with a larger diameter were found to generate lower stresses than longer implants with a smaller diameter. Other potential influential design factors including implant system, cantilever length, thread features, and abutment collar height should also be considered in future implant design as they may also have an impact on implant performance.

5.
Heliyon ; 10(2): e24529, 2024 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-38312590

RESUMO

Background: Evidence is limited regarding the relationship among physical activity, anxiety, and oral health in Chinese university students. This cross-sectional investigation aimed to assess the potential relationship between physical activity, anxiety, and oral health conditions among university students in China. Methods: An online questionnaire measuring physical activity, anxiety status, and oral health condition was completed by 1604 university students. The International Physical Activity Questionnaire Short Form (IPAQ-SF) and Generalized Anxiety Disorder-7 (GAD-7) were selected to evaluate physical activity and anxiety, respectively. Oral health condition was assessed through several self-reported variables, including self-reported toothache, gingival bleeding, frequency of tooth brushing, and use of dental floss. Multivariate logistic regression was performed to analyze the underlying relationship between outcome variables. The control variables included age, height, weight, gender, whether only one-child, education level, parental education level, smoking status, drinking habits, and length of sleep. Path analysis was conducted to disentangle the association between physical activity, anxiety, and oral health conditions. Results: Among 1604 university students, 666 (41.5 %) were males and 938 (58.5 %) were females, with an average of 21.9 ± 2.8 years. Only 833 (51.9 %) reported sufficient physical activity, while 684 (42.6 %) of the subjects displayed varying degrees of anxiety. Self-reported gingival bleeding was associated with insufficient physical activity (OR = 1.25; 95%CI: 1.02-1.55), anxiety (OR = 0.45; 95%CI: 0.27-0.74), frequency of tooth brushing (OR = 0.75; 95%CI: 0.60-0.95) and use of dental floss (OR = 0.75; 95%CI: 0.59-0.96), while toothache was not directly influenced by the physical activity and anxiety among university students. Anxiety markedly mediated the relationship between physical activity and oral health conditions. Conclusions: Anxiety was considered a factor associated with the level of physical activity, tooth brushing habits, and self-reported gingival bleeding among university students. Further investigations are required to elucidate whether oral health conditions could be enhanced through the improvement of anxiety and physical activity.

6.
Artigo em Inglês | MEDLINE | ID: mdl-38834501

RESUMO

OBJECTIVES: Artificial intelligence (AI) has been extensively used in the field of stomatology over the past several years. This study aimed to evaluate the effectiveness of AI-based models in the procedure, assessment, and treatment planning of surgical extraction. STUDY DESIGN: Following Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines, a comprehensive search was conducted on the Web of Science, PubMed/MEDLINE, Embase, and Scopus databases, covering English publications up to September 2023. Two reviewers performed the study selection and data extraction independently. Only original research studies utilizing AI in surgical extraction of stomatology were included. The Cochrane risk of bias tool for randomized trials (RoB 2) was selected to perform the quality assessment of the selected literature. RESULTS: From 2,336 retrieved references, 35 studies were deemed eligible. Among them, 28 researchers reported the pioneering role of AI in segmentation, classification, and detection, aligning with clinical needs. In addition, another 7 studies suggested promising results in tooth extraction decision-making, but further model refinement and validation were required. CONCLUSIONS: Integration of AI in stomatology surgical extraction has significantly progressed, enhancing decision-making accuracy. Combining and comparing algorithmic outcomes across studies is essential for determining optimal clinical applications in the future.


Assuntos
Inteligência Artificial , Extração Dentária , Humanos , Planejamento de Assistência ao Paciente
7.
Heliyon ; 9(2): e13476, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36820042

RESUMO

Purpose: The objective of the present study was to determine the accuracy of T-scan system and Cerec Omnicam system with respect to the evaluation of occlusal contact by quantitatively comparing the occlusal contact areas and the overlapping ratios of occlusal contact areas obtained from these systems. Material and methods: The occlusal contact of 20 adolescents with normal occlusion was measured with the T-scan system and the Cerec Omnicam system, respectively. The occlusal contact areas in the intercuspal position were then quantified with Adobe Photoshop CS6 Software. The same procedure was repeated for each subject using with 8 µm articulating paper as the control group. The overlapping ratio of T-scan system and Cerec Omnicam system was calculated respectively, which is defined as the ratio of overlapping areas comparing with those obtained from articulating paper. To examine the accuracy of T-scan system and Cerec Omnicam system, the Paired t-test was applied. The reproducibility of T-scan system was evaluated with Wilcoxon matched-pairs signed-ranks test by comparing the occlusal contact areas between two repeated measurements. In all statistical analysis, the level of significance was set to α = 0.05. Results: Results demonstrated measured occlusal contact areas were significantly different between those obtained between T-scan system and Cerec Omnicam system (P < 0.05). The tooth position of two-dimensional virtual dental arch established by T-scan system based on the width of the central incisor was in disagreement with the actual tooth position. The overlapping ratios obtained from Cerec Omnicam system were higher than those obtained from the T-Scan system (P < 0.05). The sensitivity of T-Scan system in anterior teeth area decreased when sensors are used more than once (P < 0.05). Conclusions: In the intercuspal position, the accuracy of Cerec Omnicam system for occlusal contact assessment is higher than that of T-scan system. The T-scan system demonstrates good reproducibility in the premolar region and the molar region, but poor reproducibility in the anterior teeth region. Clinical implications: In the intercuspal position, Cerec Omnicam system is more accurate than T-scan system, which can quantitatively analyze occlusal relationship in terms of number, position, size and distribution of occlusal contact points. When evaluating occlusal contacts, the accuracy of T-scan system in anterior teeth region is significantly lower than that of premolar and molar regions.

8.
Br J Oral Maxillofac Surg ; 61(6): 403-410, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37331853

RESUMO

Evidence is limited on whether titanium-zirconium alloy, narrow-diameter implants (Ti-Zr NDIs) have promising clinical outcomes when used to support single crowns. The purpose of this systematic review and meta-analysis was to evaluate clinical evidence, including survival rates, success rates, and marginal bone loss (MBL) on Ti-Zr NDIs that support single crowns. An extensive search was performed in the databases of PubMed/MEDLINE, Scopus, Embase, and the Cochrane Library for studies published in English up to April 2022. Only peer-reviewed clinical studies with at least 10 patients and a follow-up time of at least 12 months were included. Risk of bias in each study was assessed and data extraction was carried out independently by two reviewers. The outcome variables were survival rates, success rates, and MBL. The search returned 779 results. Eight studies were identified for qualitative analysis and seven for quantitative synthesis. Overall, a total of 256 Ti-Zr NDIs were included. Cumulative implant survival rates and success rates were 97.5% (95% confidence interval (CI): 94.5% to 98.9%) and 97.2% (95% CI: 94.2% to 98.7%), respectively, over a maximum follow-up period of 36 months, with no difference between Ti-Zr NDIs and commercial pure titanium (cpTi) implants. Cumulative mean (SD) MBL was 0.44 (0.04) mm (95% CI: 0.36 to 0.52) after one year. Meta-analysis of MBL indicated a mean difference of 0.02 mm (95% CI: -0.23 to 0.10), with no differences between Ti-Zr NDIs and cpTi implants. Short-term results of Ti-Zr NDIs for single-crown restorations are quite promising, although the number of published studies and follow-up periods are insufficient to determine the real benefit for single crowns. Long-term, follow-up clinical studies are needed to verify the excellent clinical performance of Ti-Zr NDIs.


Assuntos
Implantes Dentários , Titânio , Humanos , Zircônio , Planejamento de Prótese Dentária , Ligas , Coroas , Falha de Restauração Dentária
9.
Prev Med Rep ; 35: 102383, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37680854

RESUMO

Certain dental procedures produce high levels of aerosols containing pathogenic microorganisms, posing a risk for the transmission of infections in dental settings. This study aimed to assess the effectiveness of various aerosol mitigation interventions during clinical dental procedures in real-world environments. A systematic literature search was conducted in PubMed/MEDLINE, Scopus, Web of Science, and Embase for English studies up to March 2023 according to the PRISMA guidelines. Only peer-reviewed controlled clinical trials (CCT) or randomized controlled trials (RCT) studies involving human subjects were included. The risk of bias of selected researches were evaluated by two independent authors using the Cochrane Collaboration tool. The literature search yielded 3491 articles, of which 42 studies met the inclusion criteria and were included in this study. Most studies evaluated bacterial contamination in bio-aerosols, while the viral and fungal contamination was assessed in only three studies. Overall, various approaches have been applied in reducing aerosol contamination in clinical scenarios, including high-volume evacuators (HVE), mouse rinses and rubber dams, air cleaning systems, and high-efficiency particulate air (HEPA) filters. The available evidence suggests that various aerosol mitigation strategies could be implemented to decrease the risk of cross-infection during clinical dental procedures in real-world environments. However, further clinical trials are necessary to establish statistical validity in measuring aerosol contamination and mitigation, as well as to evaluate the risk of infection transmission for viral and fungal contamination.

10.
Sci Rep ; 13(1): 16773, 2023 10 05.
Artigo em Inglês | MEDLINE | ID: mdl-37798354

RESUMO

This study aimed to evaluate the accuracy of digital dental impressions obtained by intraoral scanning (IOS) for partial edentulous patients with maxillary defects by comparing them with conventional impression techniques. Ten subjects underwent an experimental procedure where three ceramic blocks were affixed to the healthy palate mucosa. Digital dental impressions were captured using IOS and subsequently imported into software. Conventional impressions obtained by silicone rubber were also taken and scanned. Linear distance and best-fit algorithm measurements were performed using conventional impression techniques as the reference. Twenty impressions were analyzed, which included 30 pairs of linear distances and 10 best-fit algorithm measurements. Regarding linear distance, paired two-sample t-test demonstrated no significant differences between IOS and model scanning in groups A and C, whereas significant differences were found in group B (P < 0.05). Additionally, ANOVA revealed significant differences among the groups (P < 0.05). No significant differences were found for the best-fit algorithm measurement of the dentition. IOS can provide accurate impressions for partial edentulous patients with maxillary defects and its accuracy was found to be comparable with conventional impression techniques. A functional impression may be needed to ensure accurate reproduction of soft and hard tissues in defect or flap areas.


Assuntos
Imageamento Tridimensional , Boca Edêntula , Humanos , Modelos Dentários , Desenho Assistido por Computador , Software , Técnica de Moldagem Odontológica
11.
J Sci Med Sport ; 26(9): 493-503, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37524627

RESUMO

OBJECTIVES: While the use of mouthguards is well established to prevent orofacial and dental trauma occurrence, limited evidence exists regarding their influence on athletic performance. The objective of this study was to conduct a systematic review of the literature to assess the effect of wearing mouthguards on athletic performance. DESIGN: Systematic review. METHODS: An extensive search was performed in the databases of PubMed/MEDLINE, Embase, Scopus and Cochrane Library for studies published up to August 2022. Only peer-reviewed studies involving humans in vivo and investigating the use of mouthguards on performance among athletes were included. Quality assessment was performed using the Cochrane Collaboration's risk of bias tool. RESULTS: The initial query yielded 4785 citations, of which 41 studies met the inclusion criteria, comprising a total of 852 athletes. Overall, wearing mouthguards was found to improve athletic performance compared to the control group (without mouthguards). Custom-made mouthguards were found to be more effective in enhancing athletic performance compared to other types of mouthguards. CONCLUSIONS: Wearing mouthguards should be advocated by athletes not only for the prevention of orofacial and dental trauma but also for their potential improvements in athletic performance in specific actions. However, caution must be exercised in interpreting these findings due to the variability in outcome measures and the lack of important methodological details.


Assuntos
Traumatismos em Atletas , Desempenho Atlético , Protetores Bucais , Humanos , Traumatismos em Atletas/prevenção & controle , Traumatismos em Atletas/epidemiologia , Desenho de Equipamento , Atletas
12.
Medicine (Baltimore) ; 101(47): e31922, 2022 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-36451461

RESUMO

BACKGROUND: The accuracy of 3-dimensional (3D) optical devices for facial soft-tissue measurement is essential to the success of clinical treatment in stomatology. The aim of the present systematic review was to summarize the accuracy of 3D optical devices used for facial soft-tissue assessment in stomatology. METHODS: An extensive systematic literature search was performed in the PubMed/MEDLINE, Embase, Scopus and Cochrane Library databases for studies published in the English language up to May 2022 in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. Peer-reviewed journal articles evaluating the facial soft-tissue morphology by 3D optical devices were included. The risk of bias was performed using the Quality Assessment Tool for Diagnostic Accuracy Studies-2 guidelines by the 2 reviewers. The potential publication bias was analyzed using the Review Manager software. RESULTS: The query returned 1853 results. A total of 38 studies were included in this review. Articles were categorized based on the principle of devices: laser-based scanning, structured-light scanning, stereophotogrammetry and red, green, blue-depth camera. CONCLUSION: Overall, the 3D optical devices demonstrated excellent accuracy and reliability for facial soft-tissue measurement in stomatology. red, green, blue-depth camera can collect accurate static and dynamic 3D facial scans with low cost and high measurement accuracy. Practical needs and availability of resources should be considered when these devices are used in clinical settings.


Assuntos
Dispositivos Ópticos , Medicina Bucal , Humanos , Reprodutibilidade dos Testes , Percepção de Profundidade , Face/diagnóstico por imagem
13.
Shanghai Kou Qiang Yi Xue ; 29(6): 611-616, 2020 Dec.
Artigo em Zh | MEDLINE | ID: mdl-33778828

RESUMO

PURPOSE: To verify the impact of alterations in the vertical position of maxillary canine on smile esthetic perceptions, in order to find an optimal canine position. METHODS: A volunteer's dentition and facial images were scanned by intra-oral scanning and three-dimensional facial scanning, which were then calibrated. In virtue of dental computer-aided design software, the canine vertical positions were symmetrically modified in a variable of 0.5 mm, creating 4 new 3D virtual digital smile faces varying from 1.0 mm of intrusion to 1.0 mm of extrusion. A total of 5 3D virtual digital smile faces were evaluated from the front and 45°to the right sides by 60 dentists and 60 laypersons on a visual analog scale. The data were input into SPSS 20.0 software package, ANOVA of repeated measurement was used to compare the differences in the assessment scores between two groups and rank sum test was used to analyze the differences from different evaluation angles. RESULTS: Alterations in the vertical position of maxillary canine had significant influence on the esthetic evaluation of the smile(P<0.05); there was significant difference between the dentists' and laypersons' esthetic evaluations after the canine vertical position being modified(P<0.05), there was no significant difference on the evaluations of smile esthetics from different evaluation perspectives(P>0.05). CONCLUSIONS: The most attractive smile was the one with canine cusp 0.5 mm vertically higher than the incisal edge of the lateral incisor. The smile is not attractive when the cusp of canine is vertically lower than the incisal edge of lateral incisor. These results can be used as references in the esthetic treatment planning for anterior maxillary teeth.


Assuntos
Estética Dentária , Sorriso , Dente Canino , Humanos , Incisivo , Percepção
14.
J Chromatogr A ; 1595: 19-27, 2019 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-30827698

RESUMO

1,2-Ethanedithiol was firstly involved in preparing sulfur-containing functional magnetic polymer material of Fe3O4@SiO2@ glycidyl methacrylate (GMA)-S-SH. The prepared Fe3O4@SiO2@GMA-S-SH magnetic nanoparticles (MNPs) show better adsorption capacity and adsorption/desorption dynamics for mercury species than other -SH functional materials due to the high affinity of both thioether and thiol group towards mercury. A new method of magnetic solid phase extraction (MSPE) using Fe3O4@SiO2@GMA-S-SH as sorbents combined with high performance liquid chromatography (HPLC)-inductively coupled plasma mass spectrometry (ICP-MS) was developed for the analysis of trace Hg2+, methylmercury (MeHg+) and phenylmercury (PhHg+). Variables affecting the simultaneous extraction of three target mercury species were investigated. It was found that Hg2+, MeHg+ and PhHg+ in 200 mL of water sample could be quantitatively adsorbed within 5 min and eluted by 0.5 mL 0.1 mol L-1 nitric acid and 4% thiocarbamide in 2 min. The developed method has high actual enrichment factors of 367, 380, 329-fold for Hg2+, MeHg+ and PhHg+, respectively. The detection limits were 0.40, 0.49 and 1.4 ng L-1 with the relative standard deviations (n = 5, inter-day) of 7.4, 8.1 and 8.3% for Hg2+, MeHg+ and PhHg+, respectively. The accuracy of the method was validated by the analysis of the Certified Reference Materials of GSS-11 soil, GSS-13 soil, GSB21 rice and DORM-2 fish. The established method was successfully used for the mercury speciation in farmland water, soil and rice samples collected from Wanshan, China, and satisfactory recoveries (84.3-116%) were obtained for the spiked samples.


Assuntos
Cromatografia Líquida de Alta Pressão , Monitoramento Ambiental/métodos , Espectrometria de Massas , Mercúrio/análise , Extração em Fase Sólida , Animais , China , Peixes , Limite de Detecção , Mercúrio/química , Compostos de Metilmercúrio/análise , Polímeros/química , Reprodutibilidade dos Testes , Dióxido de Silício/química , Enxofre/química , Água/química
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA