Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 4 de 4
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
J Mass Spectrom ; 53(3): 234-239, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29314422

RESUMO

The determination of pesticide residues is an indispensable task in controlling food safety and environment protection. Carbendazim is one of the extensive uses of pesticides in the agricultural industry. In this study, a simple method utilizing syringe filter has been applied as electrospray ionization emitter for mass spectrometric identification and quantification of carbendazim in complex matrices including soil, natural water, and fruit juice samples, which contain many insoluble materials. With online syringe filter of the complex samples, most of insoluble materials such as soil were excluded in spray ionization process due to the filter effect, and analytes were subsequently sprayed out from syringe needle for mass spectrometric detection. The pore sizes of filters and diameters of syringe needles also were investigated. The analytical performances, including the linear range (1-200 ng·mL-1 ), limit of detection (0.2-0.6 ng·mL-1 , S/N > 3), limit of quantitation (3.5-8.6 ng·mL-1 , S/N > 10), reproducibility (6.4%-12.5%, n = 6), and recoveries (72.1%-91.0%, n = 6) were well acceptable for direct analysis of raw samples. Matrix effect for detection of carbendazim in soil samples also was experimentally investigated. This study demonstrated that syringe filter needle coupled with electrospray ionization mass spectrometry is a simple, efficient, and sensitive method for detection of pesticide residues in water, soil, and fruit juice for risk assessment.


Assuntos
Benzimidazóis/análise , Carbamatos/análise , Poluentes Ambientais/análise , Resíduos de Praguicidas/análise , Cromatografia Líquida de Alta Pressão , Sucos de Frutas e Vegetais/análise , Humanos , Limite de Detecção , Reprodutibilidade dos Testes , Solo/química , Espectrometria de Massas por Ionização por Electrospray , Seringas , Espectrometria de Massas em Tandem , Poluentes Químicos da Água/análise
2.
Anal Chim Acta ; 973: 68-74, 2017 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-28502429

RESUMO

Polycyclic aromatic hydrocarbons (PAHs) are environmental contaminants with carcinogenic effect raising worldwide concerns. Hydroxylated PAHs (OH-PAHs) could be formed in the body as metabolites of PAHs in human urine samples and thus considered as biomarkers of PAH exposure. In this study, five OH-PAHs including 3-phenanthrol, 1-naphthol, 2-hydroxy fluorene, 1-hydroxprene and 6-hydroxy chrysene in human urine samples were selectively enriched by C18 solid-phase microextraction (SPME), then SPME fiber was connected high voltage and then was inserted into a glass-capillary to elute and ionize the analytes for mass spectrometric (MS) detection. The coupling of SPME-MS showed excellent analytical performance for detection of urinary OH-PAHs under optimal conditions, providing an easy operation for rapid detection of a single sample within minutes. By use of internal standard (i.e., 2-hydroxy fluorene-d9), the limit of detection (LOD) and limit of quantitation (LOQ) of OH-PAHs were found to be less than 0.05 ng L-1 level (S/N > 3) and less than 0.1 ng L-1 level (S/N > 10), respectively. The dynamic ranges of five OH-PAHs were found to be a range at 0.1-5.0 ng L-1 with excellent coefficient (R2 > 0.99). This method also showed good precisions (intra-day: 3.4-5.5%, inter-day: 7.0-9.8%, n = 5) and good accuracy (85.3-95.3%, n = 5). Moreover, ion suppression and matrix effect in detection of OH-PAHs in urine were also investigated. Human urine samples collected from 12 volunteers including 6 non-smokers and 6 smokers have been successfully analyzed, it was found that individual OH-PAHs in smokers were higher than in non-smokers. This study demonstrated that SPME coupled with glass-capillary nanoESI-MS is a sensitive method for rapid detection of urinary OH-PAHs for health risk assessment of PAHs exposure.


Assuntos
Espectrometria de Massas , Hidrocarbonetos Policíclicos Aromáticos/urina , Microextração em Fase Sólida , Biomarcadores/urina , Humanos
3.
Mil Med Res ; 1: 10, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25722868

RESUMO

BACKGROUND: The treatment of hypertensive spontaneous intracranial hemorrhage (ICH) is still controversial. The purpose of the present study was to investigate whether minimally invasive puncture and drainage (MIPD) could improve patient outcome compared with decompressive craniectomy (DC). METHODS: Consecutive patients with ICH (≧30 mL in basal ganglia within 24 hours of ictus) were non-randomly assigned to receive MIPD (group A) or DC (group B) hematoma evacuation. The primary outcome was death at 30 days after onset. Functional independence was assessed at 1 year using the Glasgow Outcome Scale. RESULTS: A total of 198 patients met the per protocol analysis (84 in group A and 114 in group B). The initial Glasgow Coma Scale (GCS) score was 8.1 ± 3.4 and the National Institutes of Health Stroke Scale (NIHSS) score was 20.8 ± 5.3. The mean hematoma volume (HV) was 56.7 ± 23.0 mL, and there was extended intraventricular hemorrhage (IVH) in 134 patients. There were no significant intergroup differences in the above baseline data, except group A had a higher mean age than that of group B (59.4 ± 14.5 vs. 55.3 ± 11.1 years, P = 0.025). The cumulative mortalities at 30 days and 1 year were 32.3% and 43.4%, respectively, and there were no significant differences between groups A and B. However, the mortality for patients ≦60 years, NIHSS < 15 or HV≦60 mL was significantly lower in group A than that in group B (all P < 0.05). The cumulative functional independence at 1 year was 26.8%, and the difference between group A (33/84, 39.3%) and group B (20/114, 17.5%) was significant (P = 0.001). Multivariate logistic regression analysis showed that a favorable outcome after 1 year was associated with the difference in therapies, age, GCS, HV, IVH and pulmonary infection (all P <0.05). CONCLUSIONS: For patients with hypertensive spontaneous ICH (HV≧30 mL in basal ganglia), MIPD may be a more effective treatment than DC, as assessed by a higher rate of functional independence at 1 year after onset as well as reduced mortality in patients ≦60 years of age, NIHSS < 15 or HV≦60 mL.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...