Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 18 de 18
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Sci Rep ; 14(1): 6748, 2024 03 21.
Artigo em Inglês | MEDLINE | ID: mdl-38514826

RESUMO

The data regarding primary FSGS (pFSGS) from different parts of the world differ. While the prevalence of pFSGS has been increasing in Western countries like the USA, it follows an inconsistent trend in Europe and Asia and a decreasing trend in Far Eastern countries such as China in the last two decades. There are undetermined factors to explain those national and geographic discrepancies. Herein, we aimed to reveal the current prevalence with clinical and histopathological characteristics of pFSGS in Turkish adults. This study includes the biopsy-proven pFSGS patients data recorded between 2009 and 2019, obtained from the national multicenter primary glomerulonephritis registry system of the Turkish Society of Nephrology Glomerular Diseases (TSN-GOLD) database. 850 of the 3875 primer glomerulonephritis patients(21.9%) have pFSGS. The mean age is 40.5 ± 14.2 and 435 (51.2%) of patients are male. Nephrotic syndrome is the most common biopsy indication (59.2%). 32.6% of patients have hematuria, 15.2% have leukocyturia and 7.8% have both. Serum creatinine, albumin, and proteinuria are 1.0 mg/dL (IQR = 0.7-1.4) mg/dl, 3.4 ± 0.9 g/dl, 3400 mg/day(IQR, 1774-5740), respectively. Females have lower mean arterial pressure (- 2.2 mmHg), higher eGFR (+ 10.0 mL/min/1.73 m2), and BMI (+ 1.6 kg/m2) than males. Thickened basal membrane(76.6%) and mesangial proliferation (53.5%) on light microscopy are the major findings after segmental sclerosis. IgM (32.7%) and C3 (32.9%) depositions are the most common findings on immunofluorescence microscopy. IgM positivity is related to lower eGFR, serum albumin, and higher proteinuria. The prevalence of pFSGS is stable although slightly increasing in Turkish adults. The characteristics of the patients are similar to those seen in Western countries.


Assuntos
Glomerulonefrite , Glomerulosclerose Segmentar e Focal , Adulto , Feminino , Humanos , Masculino , Biópsia , Glomerulosclerose Segmentar e Focal/epidemiologia , Glomerulosclerose Segmentar e Focal/patologia , Imunoglobulina M , Proteinúria , Estudos Retrospectivos , Albumina Sérica , Estudos Multicêntricos como Assunto , Pessoa de Meia-Idade
2.
Int Urol Nephrol ; 54(3): 619-625, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34213714

RESUMO

BACKGROUND: Several factors play a role in the pathogenesis of pruritus in uremic patients. The pathophysiology is complex and many factors have been identified in these patients. The aim of this study was to investigate the presence, severity, and possible causes of pruritus in patients with peritoneal dialysis (PD) . METHODS: Eighty patients, who received continuous ambulatory peritoneal dialysis (CAPD) treatment, were included in this study. Biochemical measurements, parathormone, C-reactive protein (CRP), and vitamin B12 levels of all the patients were recorded. Furthermore, substance P (SP) levels were measured by ELISA methods. Patients were examined by a dermatologist and pruritus degrees were queried using the visual analog score (VAS) with skin dryness. RESULTS: In generalized linear model analysis, total urea clearance and SP independently predicted VAS scores. SP was significantly predictive in ROC analysis in identifying the VAS score in patients with peritoneal dialysis. The sensitivity and specificity of SP were 80% and 67% (cut-off > 364), respectively, with an area under the ROC curve of 0.757 (95% CI 0.650-0.865, p < 0.001). SP also was significantly predictive in ROC analysis in identifying xerosis in PD patients. CONCLUSION: Pruritus was proportional to the amount of substance P and total urea clearance was another reason affecting pruritus in peritoneal dialysis patients.


Assuntos
Diálise Peritoneal Ambulatorial Contínua/efeitos adversos , Prurido/etiologia , Adulto , Idoso , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Índice de Gravidade de Doença
3.
BMC Nephrol ; 22(1): 352, 2021 10 28.
Artigo em Inglês | MEDLINE | ID: mdl-34711174

RESUMO

BACKGROUND: Galactose-deficient IgA1 (Gd-IgA1) has an increased tendency to form immunocomplexes with IgG in the serum, contributing to IgAN pathogenesis by accumulating in the glomerular mesangium. Several studies showed that glomerular IgG deposition in IgAN is an important cause of mesangial proliferation and glomerular damage. This study aims to determine the association of the positivity of IgG and the intensity of IgG staining with a poor renal prognosis. METHODS: A total of 943 IgAN patients were included in the study. Glomerular IgG staining negative and positive patients were compared using Oxford classification scores, histopathological evaluations, proteinuria, eGFR, albumin, blood pressures. IgG positive patients were classified as (+), (++), (+++) based on their staining intensity, and the association with the prognostic criteria was also evaluated. RESULTS: 81% (n = 764) of the patients were detected as IgG negative, while 19% (n = 179) were positive. Age, gender, body mass index, blood pressure, proteinuria, eGFR, uric acid values were similar in IgG positive and negative patients who underwent biopsy (p > 0.05). Intensity of glomerular IgG positivity was not found to be associated with diastolic and systolic blood pressure, urea, uric acid, age, eGFR, albumin, proteinuria (p > 0.05 for all, r = - 0.084, r = - 0.102, r = - 0.006, r = 0.062, r = 0.014, r = - 0.044, r = - 0.061, r = - 0.066, r = 0.150, respectively). There was no difference for histopathological findings between IgG (+), IgG (++), IgG (+++) groups (for all, p > 0.05). CONCLUSION: Glomerular IgG negativity and positivity detected by routine IFM in IgAN patients is not associated with poor renal prognostic risk factors.


Assuntos
Glomerulonefrite por IGA/patologia , Imunoglobulina G/análise , Glomérulos Renais/química , Adulto , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Estudos Retrospectivos , Coloração e Rotulagem
4.
Int Urol Nephrol ; 52(11): 2197-2203, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32948926

RESUMO

OBJECTIVE: This study aimed to investigate the relationship between fluid and sodium excretion and blood pressure, echocardiographic parameters, and arterial stiffness in peritoneal dialysis (PD) patients and to evaluate the effect of sodium excretion on patients' survival. METHOD: This study was conducted as a single-centered, prospective study in the Department of Nephrology in Erciyes University. The patients included in the study were followed up for 3 years. Seventy PD patients were included in the study. We recorded demographic characteristics, biochemical parameters, urine and peritoneal ultrafiltration volumes, peritoneal equalization tests, ambulatory blood pressure measurements, and echocardiographic measurements. We measured the amount of total sodium excretion of the patients and arterial stiffness using pulse wave velocity (PWV). Patients were divided into two groups based on the amount of total sodium excretion: low group and high group. We compared these groups in terms of cardiac and biochemical parameters. RESULTS: When demographic data and biochemical values were compared, there was no significant difference between the two groups. NT-proBNP level, systolic blood pressure, and mean arterial pressure were significantly higher in the low group (p: 0.02, p: 0.031, p: 0.05, respectively). Net ultrafiltration was significantly higher in the high group (p: 0.03), was also found to be high in patients with high sodium excretion (p: 0.001). Negative correlations were found between sodium excretion and net ultrafiltration, NT-Pro BNP, and PWV. At the end of the 3-year follow-up, the survival rate was shorter and the mortality rate was higher in the low group (p: 0.042). DISCUSSION AND CONCLUSION: Fluid status in PD patients can affect arterial stiffness both directly and through hypertension. Correction of hypervolemia has the potential to not only prevent hypertension and left ventricular hypertrophy, but also to improve arterial stiffness, a well-known cardiovascular risk factor. The mortality rate was higher in PD patients with low total sodium excretion. Therefore, these patients should be followed more closely to ensure volume control.


Assuntos
Pressão Arterial , Endotélio Vascular/fisiopatologia , Falência Renal Crônica/fisiopatologia , Falência Renal Crônica/terapia , Diálise Peritoneal , Sódio/metabolismo , Rigidez Vascular , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Soluções para Hemodiálise , Humanos , Falência Renal Crônica/metabolismo , Falência Renal Crônica/mortalidade , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Taxa de Sobrevida , Adulto Jovem
5.
Int J Rheum Dis ; 20(5): 628-638, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-26176346

RESUMO

BACKGROUND: The aim of this study was to investigate the relationship between central blood pressure, arterial stiffness parameters and renal function parameters in gout patients with chronic kidney disease (CKD) and without CKD. METHODS: The study enrolled 48 gout patients and 32 control subjects. Central blood pressure, arterial stiffness parameters and renal function parameters in gout patients were investigated. The vascular measurements were performed with an arteriograph. RESULTS: Of the gout patients, 40.1% had CKD. The 24-h pulse pressure (PP) (P < 0.001), central systolic blood pressure (SBP) (P < 0.001), central diastolic blood pressure (DBP) (P < 0.001), cardiac output (CO) (P < 0.001) and peripheral resistance (P = 0.004) were significantly higher in the all patients with gout compared to healthy control subjects. Moreover, when the gout patients with and without CKD were compared, the gout patients with CKD had higher 24-h PP (P = 0.009), 24-h augmentation index standardized to a heart rate of 75 beats per min (AIx@75) (P < 0.023), daytime PP (P = 0.001), daytime AIx@75 (P = 0.027), and nighttime PP (P = 0.035) than the gout patients without CKD. CONCLUSIONS: In our study, gout patients with CKD had worse and more emphasized evidence of arterial stiffness than gout patients without CKD. Further investigations with large sample sizes are needed to evaluate the effect of CKD on the arterial stiffness of gout patients.


Assuntos
Pressão Arterial , Artéria Braquial/fisiopatologia , Gota/complicações , Insuficiência Renal Crônica/complicações , Rigidez Vascular , Adulto , Idoso , Idoso de 80 Anos ou mais , Débito Cardíaco , Estudos de Casos e Controles , Estudos Transversais , Feminino , Gota/diagnóstico , Gota/fisiopatologia , Frequência Cardíaca , Humanos , Rim/fisiopatologia , Masculino , Pessoa de Meia-Idade , Prognóstico , Análise de Onda de Pulso , Insuficiência Renal Crônica/diagnóstico , Insuficiência Renal Crônica/fisiopatologia , Fatores de Risco , Resistência Vascular
6.
Clin Exp Hypertens ; 35(6): 430-6, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23216063

RESUMO

The aim of this study was to investigate the relationship between central blood pressures (BP), pulse wave velocity (PWV) meaurements, and biochemical parameters in female and male gout patients and controls. This study included 12 (23.5%) females and 39 (76.5%) males with gout disease. 24-hour diastolic BP, day diastolic BP and day diastolic exceeding limit value were higher in male gout patients than female gout patients. In male gout patients, more prominent inflammatory changes in the vascular wall may be an explanation for the result of this our study, because history of hypertension and smoking habits were frequent in this group.


Assuntos
Gota/fisiopatologia , Rigidez Vascular/fisiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Pressão Sanguínea , Estudos de Casos e Controles , Feminino , Gota/sangue , Humanos , Masculino , Pessoa de Meia-Idade , Análise de Onda de Pulso , Fatores de Risco , Ácido Úrico/sangue , Adulto Jovem
7.
Anal Chim Acta ; 688(1): 75-83, 2011 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-21296208

RESUMO

Activated carbon was produced from tea-industry wastes (TIWAC) and employed as a low cost and effective solid phase material for the separation, preconcentration and speciation of chromium species without using a complexing agent, prior to determination by flame atomic absorption spectrometry (FAAS). The characterization of TIWAC was performed by utilizing several techniques such as Fourier Transform Infrared (FTIR) Spectroscopy, Scanning Electron Microscopy (SEM), and elemental analysis. The adsorption experiments were conducted in a batch adsorption technique. Under the experimental conditions, Cr(VI) adsorption amount was nearly equal to zero, however the adsorption percentage of Cr(III) was in the range of 95-100%. Therefore total chromium was determined after the reduction of Cr(VI) to Cr(III) and Cr(VI) was calculated by subtracting Cr(III) concentration from total chromium concentration. The suitable conditions for adsorption and speciation processes were evaluated in terms of pH, eluent type and volume, TIWAC concentration, adsorption and desorption contact time, etc. Adsorption capacity of TIWAC was found to be 61.0 mg g(-1). The detection limit for Cr(III) was found to be 0.27 µg L(-1) and the preconcentration factor was 50 for 200mL of sample volume. The procedure was applied to the determination and speciation of chromium in stream, tap and sea water. Also, the proposed method was applied to total chromium preconcentration in microwave digested tobacco and dried eggplant samples with satisfactory results. The method was validated by analyzing certified reference materials (CRM-TMDW-500 Drinking Water and CRM-SA-C Sandy Soil C) and the results were in good agreement with the certified values.


Assuntos
Carbono/química , Cromo/análise , Resíduos Industriais/análise , Espectrofotometria Atômica/métodos , Poluentes Químicos da Água/análise , Cromo/isolamento & purificação , Concentração de Íons de Hidrogênio , Cinética , Oxirredução , Chá/química , Poluentes Químicos da Água/isolamento & purificação
8.
Environ Monit Assess ; 165(1-4): 1-13, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-19404755

RESUMO

This paper presents a comprehensive evaluation of drinking water quality from the stream Galyan and its tributary, the stream Kustul, in Trabzon Province, Turkey. In this study, surface water quality data for 20 physical and chemical parameters were determined and collected from three monitoring stations of the understudy stream during April 2004 to March 2005. According to the Turkish Water Pollution Control Regulation, the stream Galyan water was classified, and the studied parameters were evaluated for the values proposed by Turkish Standard (TS) 266 and World Health Organization (WHO) guidelines. The results showed that TS 266 and WHO guidelines were exceeded for Fe (up to 860 microg/l) and Cr (up to 134.7 microg/l). Pearson's correlation was also used to determine the relationship of the studied parameters and as a result significant correlations were observed between some parameters.


Assuntos
Água Doce/química , Metais/análise , Poluentes Químicos da Água/análise , Monitoramento Ambiental/métodos , Turquia
9.
J Hazard Mater ; 172(1): 353-62, 2009 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-19656623

RESUMO

A natural bentonite modified with a cationic surfactant, cetyl trimethylammonium bromide (CTAB), was used as an adsorbent for removal of phenol from aqueous solutions. The natural and modified bentonites (organobentonite) were characterized with some instrumental techniques (FTIR, XRD and SEM). Adsorption studies were performed in a batch system, and the effects of various experimental parameters such as solution pH, contact time, initial phenol concentration, organobentonite concentration, and temperature, etc. were evaluated upon the phenol adsorption onto organobentonite. Maximum phenol removal was observed at pH 9.0. Equilibrium was attained after contact of 1h only. The adsorption isotherms were described by Langmuir and Freundlich isotherm models, and both model fitted well. The monolayer adsorption capacity of organobentonite was found to be 333 mg g(-1). Desorption of phenol from the loaded adsorbent was achieved by using 20% acetone solution. The kinetic studies indicated that the adsorption process was best described by the pseudo-second-order kinetics (R(2) > 0.99). Thermodynamic parameters including the Gibbs free energy (DeltaG degrees), enthalpy (DeltaH degrees), and entropy (DeltaS degrees) were also calculated. These parameters indicated that adsorption of phenol onto organobentonite was feasible, spontaneous and exothermic in the temperature range of 0-40 degrees C.


Assuntos
Fenol/isolamento & purificação , Poluentes Químicos da Água/isolamento & purificação , Purificação da Água/métodos , Adsorção , Bentonita/química , Cetrimônio , Compostos de Cetrimônio/química , Concentração de Íons de Hidrogênio , Cinética , Microscopia Eletrônica de Varredura/métodos , Fenol/química , Espectrofotometria/métodos , Espectroscopia de Infravermelho com Transformada de Fourier , Temperatura , Termodinâmica , Fatores de Tempo , Difração de Raios X
10.
J AOAC Int ; 92(1): 257-62, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19382584

RESUMO

A coprecipitation method has been established for speciation of chromium(III) and chromium(VI) in real samples. The procedure is based on the coprecipitation of Cr(III), by using a new organic coprecipitant, 3-phenyl-4-o-hydroxybenzyl-idenamino-4,5-dihydro-1,2,4-triazole-5-one, without adding any carrier element. After reduction of Cr(VI) by concentrated H2SO4 and ethanol, the method was applied to the determination of total Cr. The level of Cr(VI) was calculated by the difference of total Cr and Cr(III) levels. For optimum recovery of Cr(III), different analytical factors such as pH, amount of coprecipitant, centrifugation rate and time, and effect of sample volume, were investigated. The influences of some anions, cations, and transition metals on the recoveries were also investigated, and no significant interferences were observed. The preconcentration factor was 100. The detection limit based on 3 times standard deviation (sigma) of the blank (n = 10) for Cr(III) was 0.50 microg/L. In order to evaluate the accuracy of the method, certified reference materials (CRM-TMDW-500 Drinking Water and National Institute of Standards and Technology Standard Reference Material 1573a Tomato Leaves) were analyzed, and the results obtained were in good agreement with certified values. The presented procedure was applied for Cr speciation in various solid and liquid samples with successful results.


Assuntos
Cromo/análise , Abastecimento de Água/normas , Ânions/análise , Cátions/análise , Cromo/isolamento & purificação , Concentração de Íons de Hidrogênio , Indicadores e Reagentes , Solanum lycopersicum/química , Folhas de Planta/química , Sensibilidade e Especificidade , Triazóis , Água/análise , Abastecimento de Água/análise
11.
J Hazard Mater ; 168(2-3): 888-94, 2009 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-19327886

RESUMO

The present study was carried out to assess the ability of original waste mud (o-WM) and different types of activated waste mud which are acid-activated (a-WM) and precipitated waste mud (p-WM), in order to remove excess of fluoride from aqueous solution by using batch technique. The p-WM exhibited greater performance than the others. Adsorption studies were conducted as a function of pH, contact time, initial fluoride concentration, adsorbent concentration, temperature, etc. Studies were also performed to understand the effect of some co-existing ions present in aqueous solutions. Adsorption process was found to be almost independent of pH for all types of waste mud. Among the kinetic models tested for p-WM, pseudo-second-order model fitted the kinetic data well with a perfect correlation coefficient value of 1.00. It was found that the adequate time for the adsorption equilibrium of fluoride was only 1h. Thermodynamic parameters including the Gibbs free energy (DeltaG degrees ), enthalpy (DeltaH degrees ), and entropy (DeltaS degrees ) revealed that adsorption of fluoride ions on the p-WM was feasible, spontaneous and endothermic in the temperature range of 0-40 degrees C. Experimental data showed a good fit with the Langmuir and Freundlich adsorption isotherm models. Results of this study demonstrated the effectiveness and feasibility of WM for removal of fluoride ions from aqueous solution.


Assuntos
Fluoretos/isolamento & purificação , Adsorção , Concentração de Íons de Hidrogênio , Cinética , Soluções , Termodinâmica , Água/química
12.
J Hazard Mater ; 167(1-3): 294-9, 2009 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-19181444

RESUMO

A separation/preconcentration procedure, based on the coprecipitation of Cr(3+), Fe(3+), Pb(2+) and Zn(2+) ions using a new organic coprecipitant, 3-phenly-4-o-hydroxybenzylidenamino-4,5-dihydro-1,2,4-triazole-5-one (POHBAT) without adding any carrier element has been developed. The method, thus, has been called carrier element-free coprecipitation (CEFC). The resultant concentrated elements were determined by flame atomic absorption spectrometric determinations. The influences of some analytical parameters including pH of the solution, amount of the coprecipitant, standing time, centrifugation rate and time, sample volume and diverse ions were investigated on the quantitative recoveries of analyte ions. The validation of the present preconcentration procedure was performed by the analysis of two certified reference materials. The recoveries of understudy analytes were found in the range of 93-98%, while the detection limits were calculated in the range of 0.3-2.0 microg L(-1). The precision of the method evaluated as relative standard deviation (R.S.D.), was in the range of 3-7% depend on the analytes. The proposed method was successfully applied to environmental samples for the determination of the analytes.


Assuntos
Triazóis/química , Poluentes Químicos da Água/isolamento & purificação , Precipitação Química , Cromo/isolamento & purificação , Poluentes Ambientais/isolamento & purificação , Ferro/isolamento & purificação , Chumbo/isolamento & purificação , Padrões de Referência , Espectrofotometria Atômica , Zinco/isolamento & purificação
13.
J Hazard Mater ; 166(2-3): 1480-7, 2009 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-19167162

RESUMO

The objective of this study was to assess the adsorption potential of a waste mud (WM) for the removal of lead (Pb(II)) ions from aqueous solutions. The WM was activated with NaOH in order to increase its adsorption capacity. Adsorption studies were conducted in a batch system as a function of solution pH, contact time, initial Pb(II) concentration, activated-waste mud (a-WM) concentration, temperature, etc. Optimum pH was specified as 4.0. The adsorption kinetic studies indicated that the overall adsorption process was best described by pseudo-second-order kinetics. The equilibrium adsorption capacity of a-WM was obtained by using Langmuir and Freundlich isotherm models and both models fitted well. Adsorption capacity for Pb(II) was found to be 24.4 mg g(-1) for 10 g L(-1) of a-WM concentration. Thermodynamic parameters including the Gibbs free energy (Delta G degrees), enthalpy (Delta H degrees), and entropy (DeltaS degrees) indicated that the adsorption of Pb(II) ions on the a-WM was feasible, spontaneous and endothermic, at temperature range of 0-40 degrees C. Desorption studies were carried out successfully with diluted HCl solutions. The results indicate that a-WM can be used as an effective and no-cost adsorbent for the treatment of industrial wastewaters contaminated with Pb(II) ions.


Assuntos
Cobre , Resíduos Industriais/prevenção & controle , Chumbo/isolamento & purificação , Mineração , Adsorção , Concentração de Íons de Hidrogênio , Íons , Cinética , Hidróxido de Sódio , Soluções , Temperatura , Termodinâmica , Eliminação de Resíduos Líquidos/métodos , Poluentes Químicos da Água/isolamento & purificação
14.
Anal Chim Acta ; 632(1): 35-41, 2009 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-19100880

RESUMO

A new, simple, rapid and sensitive separation, preconcentration and speciation procedure for chromium in environmental liquid and solid samples has been established. The present speciation procedure for Cr(III) and Cr(VI) is based on combination of carrier element-free coprecipitation (CEFC) and flame atomic absorption spectrometric (FAAS) determinations. In this method a newly synthesized organic coprecipitant, 5-chloro-3-[4-(trifluoromethoxy) phenylimino]indolin-2-one (CFMEPI), was used without adding any carrier element for coprecipitation of chromium(III). After reduction of chromium(VI) by concentrated H(2)SO(4) and ethanol, the procedure was applied for the determination of total chromium. Chromium(VI) was calculated as the difference between the amount of total chromium and chromium(III). The optimum conditions for coprecipitation and speciation processes were investigated on several commonly tested experimental parameters, such as pH of the solution, amount of coprecipitant, sample volume, etc. No considerable interference was observed from the other investigated anions and cations, which may be found in natural water samples. The preconcentration factor was found to be 40. The detection limit for chromium(III) corresponding to three times the standard deviation of the blank (N=10) was found 0.7 microg L(-1). The present procedure was successfully applied for speciation of chromium in several liquid and solid environmental samples. In order to support the accuracy of the method, the certified reference materials (CRM-TMDW-500 Drinking Water and CRM-SA-C Sandy Soil C) were analyzed, and standard APDC-MIBK liquid-liquid extraction method was performed. The results obtained were in good agreement with the certified values.

15.
Talanta ; 76(2): 469-74, 2008 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-18585308

RESUMO

A new co-precipitation method was developed to separate and pre-concentrate Fe(3+), Cu(2+), Cr(3+), Zn(2+), and Pb(2+) ions using an organic co-precipitant, 3-benzyl-4-p-nitrobenzylidenamino-4,5-dihydro-1,2,4-triazole-5-on (BPNBAT) without adding any carrier element, following flame atomic absorption spectrometric (FAAS) determinations. Effect of some analytical conditions, such as pH of the solution, quantity of the co-precipitant, standing time, centrifugation rate and time, sample volume, and interference of concomitant ions were investigated over the recovery yields of the metal ions. The recoveries of the analyte ions were in the range of 95-102%. The detection limits, corresponding to three times the standard deviation of the blank, were found to be in the range of 0.3-2.0 microg L(-1). The precision of the method, evaluated as the relative standard deviation (R.S.D.) obtained after analyzing a series of 10 replicates, was between 1.6% and 6.0% for the trace metal ions. The method was validated by analyzing two certified reference materials and spiked addition. The proposed procedure was applied for the trace metal ions in some environmental samples.


Assuntos
Oligoelementos/isolamento & purificação , Triazóis/química , Precipitação Química , Reprodutibilidade dos Testes , Espectrofotometria Atômica , Oligoelementos/análise
16.
J Hazard Mater ; 149(2): 317-23, 2007 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-17482351

RESUMO

A simple and accurate method was developed for separation and enrichment of trace levels of gold in environmental samples. The method is based on the adsorption of Au(III)-diethyldithiocarbamate complex on Amberlite XAD-2000 resin prior to the analysis of gold by flame atomic absorption spectrometry after elution with 1 molL(-1) HNO3 in acetone. Some parameters including nitric acid concentration, eluent type, matrix ions, sample volume, sample flow rate and adsorption capacity were investigated on the recovery of gold(III). The recovery values for gold(III) and detection limit of gold were greater than 95% and 16.6 microgL(-1), respectively. The preconcentration factor was 200. The relative standard deviation of the method was <6%. The adsorption capacity of the resin was 12.3 mg g(-1). The validation of the presented procedure was checked by the analysis of CRM-SA-C Sandy Soil certified reference material. The presented procedure was applied to the determination of gold in some environmental samples.


Assuntos
Ouro/química , Ouro/isolamento & purificação , Absorção , Ditiocarb/química , Íons/química , Ácido Nítrico/química , Espectrofotometria Atômica
17.
J Hazard Mater ; 146(1-2): 347-55, 2007 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-17223260

RESUMO

A new method using a column packed with Amberlite XAD-2010 resin as a solid-phase extractant has been developed for the multi-element preconcentration of Mn(II), Co(II), Ni(II), Cu(II), Cd(II), and Pb(II) ions based on their complex formation with the sodium diethyldithiocarbamate (Na-DDTC) prior to flame atomic absorption spectrometric (FAAS) determinations. Metal complexes sorbed on the resin were eluted by 1 mol L(-1) HNO3 in acetone. Effects of the analytical conditions over the preconcentration yields of the metal ions, such as pH, quantity of Na-DDTC, eluent type, sample volume and flow rate, foreign ions etc. have been investigated. The limits of detection (LOD) of the analytes were found in the range 0.08-0.26 microg L(-1). The method was validated by analyzing three certified reference materials. The method has been applied for the determination of trace elements in some environmental samples.


Assuntos
Poluentes Ambientais/análise , Metais Pesados/análise , Acetona/química , Adsorção , Camellia sinensis/química , Corylus/química , Ditiocarb/química , Poluentes Ambientais/química , Concentração de Íons de Hidrogênio , Metais Pesados/química , Águas Minerais/análise , Ácido Nítrico/química , Resinas Sintéticas/química , Rios/química , Extração em Fase Sólida , Espectrofotometria Atômica/métodos
18.
J Hazard Mater ; 146(1-2): 155-63, 2007 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-17222968

RESUMO

A method for the preconcentration of some transition elements at trace level was proposed using a column filled with Amberlite XAD-2000 resin. Metal ions were adsorbed on XAD-2000 as their diethyldithiocarbamate chelates, then analytes retained on the resin were eluted by 1 mol L(-1) nitric acid in acetone and determined by flame atomic absorption spectrometry (FAAS). The influences of some analytical parameters including pH of sample solution, ligand amount, the type, concentration and volume of elution solution, flow rates of the sample and eluent solutions, adsorption capacity of the resin and sample volume on the preconcentration efficiency have been investigated. The influences of some matrix elements were also examined. The detection limit (N=20, 3 sigma) for Mn(II), Fe(II), Co(II), Cu(II), Cd(II), Zn(II), Pb(II) and Ni(II) were found as 0.20, 0.35, 0.25, 0.20, 0.20, 0.15, 0.45 and 0.25 microg L(-1), respectively. The validation of the procedure was carried out by analysis of certified reference materials. The proposed method was applied to natural waters and kale vegetable (Brassica oleracea var. acephala).


Assuntos
Brassica/química , Metais Pesados/análise , Poluentes Químicos da Água/análise , Ditiocarb/química , Monitoramento Ambiental , Concentração de Íons de Hidrogênio , Metais Pesados/química , Poliestirenos/química , Resinas Sintéticas/química , Extração em Fase Sólida , Turquia , Poluentes Químicos da Água/química
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...