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1.
Neurol Neurochir Pol ; 58(1): 60-65, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-37466321

RESUMO

INTRODUCTION: It is known that multiple sclerosis (MS) often coexists with other autoimmune diseases. Hence, autoantibody (auto-Ab) tests may prove useful in the differential diagnosis of MS. The objectives of this study were to: (a) investigate the prevalence of auto-Ab positivity at the beginning of the MS diagnostic process; (b) assess whether Auto-Ab+ and Auto-Ab- patients differ in baseline clinical, laboratory, and radiological parameters; and (c) investigate the prognostic value during a two-year follow-up period. MATERIAL AND METHODS: This retrospective study consisted of 450 patients aged between 18 and 55 years. All patients underwent a wide range of auto-Ab tests, anti-nuclear antibody (ANA) tests in particular. The expanded disability status scale (EDSS) scores of the patients were recorded at the time of diagnosis and at the end of a two-year follow-up period. RESULTS: The mean age of the 212 patients, 148 (69.8%) female and 64 (30.2%) male, included in the study sample was 37 ± 10.83 years. The rate of relapsing cases was 84% (178). Oligoclonal band (OCB) was positive in 142 (86.6%) of the 164 tested cases. At least one of the auto-Ab tests was positive in 51 (24.1%) of the cases. ANA test was positive in 21 (9.9%) cases. There was no significant difference between patients with at least one positive auto-Ab test and without any positive auto-Ab test and between ANA-positive and ANA-negative patients in terms of age, gender, clinical features of MS, presence of brain stem lesion, presence of spinal lesion, OCB positivity, level of clinical improvement after the first pulse steroid treatment, family history, presence of comorbidity, presence of autoimmune disease, or EDSS scores recorded at the end of the two-year follow-up period (p > 0.05). CONCLUSIONS: Our study findings revealed that Auto-Ab positivity was more common in MS patients than in the general population. However, given their limited contribution to the diagnosis and differential diagnosis of MS with no effect on the prognostic process, auto-Ab tests should be requested only in the event of accompanying autoimmune disease symptoms, and in cases where the diagnosis of MS may be suspected.


Assuntos
Autoanticorpos , Esclerose Múltipla , Humanos , Masculino , Feminino , Adolescente , Adulto Jovem , Adulto , Pessoa de Meia-Idade , Esclerose Múltipla/diagnóstico , Prognóstico , Estudos Retrospectivos , Relevância Clínica , Bandas Oligoclonais
2.
Environ Monit Assess ; 193(1): 17, 2021 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-33389185

RESUMO

The bioaccessibility of some elements (As, B, Cd, Cu, Fe, Mn, Ni and Zn) in soils and vegetables was determined using the physiologically based extraction test. An investigation of the geochemical phases of soils through sequential extraction methods followed by ICP-MS detection was also undertaken. Samples were collected from Iskele, Begendikler and Yolbasi villages in the Bigadic region and Yildiz village in the Susurluk region of Balikesir province, Turkey. All of these villages are close to boron mines. Principal component analysis and correlation analysis demonstrated the interrelationship between the bioaccessibility values of these elements in the gastric and intestinal extracts of soils as well as the plant samples grown in those soils and the elements' concentrations in the different soil fractions. From the bioaccessible concentrations of the elements in the intestinal phases, it was shown that the amounts of As, B, Cu, Mn and Ni in some plant samples were higher than the recommended and tolerable values for human consumption. The bioaccessibilty of these elements in the soils and plants were statistically related with the concentrations of these elements in the labile phases of the soil. The methodology adopted here would be applicable to determining interactions between elements and soil fractions and the interrelationships between bioaccessibility data and soil fractions for any soil samples.


Assuntos
Poluentes do Solo , Solo , Boro , Monitoramento Ambiental , Humanos , Poluentes do Solo/análise , Turquia , Verduras
3.
Talanta ; 200: 41-50, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31036203

RESUMO

Two sequential extraction methods (BCR sequential extraction method and a newly proposed sequential extraction method) were used to evaluate the bioavailability of the elements from the contaminated soils to different plants. The concentrations of As, B, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb and Zn in acid digests from different plants collected from the fields near to boron mines in Turkey were determined using ICP-MS. The levels of the elements in some plants exceeded the limits of maximum and guideline levels for As, Cd and Pb; Tolerable Upper Intake Levels (ULs) for Ni and B; Adequate Intakes (AIs) for Cr and Mn and Recommended Dietary Allowances (RDAs) for Cu, Fe and Zn. The average Transfer Factor values for elements were in the order of B>Ni>Zn>Cu>Cr>Co>Fe>Mn>Cd>Pb>As. In most cases, Principal Component Analysis and correlation analysis showed that these methods gave similar results. However, the newly proposed sequential extraction method is a more detailed method, capable of separating metals associated with manganese oxides and iron as amorphous and crystalline fractions. Three different fractions are produced for these environmental phases instead of the BCR sequential extraction procedure in which they are represented together in the second fraction. The new method therefore specifically fractionates bioavailable manganese and iron to plants.


Assuntos
Monitoramento Ambiental , Metais Pesados/análise , Poluentes do Solo/análise , Solanum lycopersicum/química , Disponibilidade Biológica , Solo/química , Turquia
4.
Talanta ; 194: 189-198, 2019 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-30609521

RESUMO

The mobility of As, B, Ba, Cd, Co, Cr, Cu, Ni, Pb and Zn in the soils collected from fields near boron mines was investigated using a new sequential extraction method and the BCR sequential extraction methods. The new sequential extraction method fractionates elements in more detail as F1 (water soluble and exchangeable fraction), F2 (bound to carbonates), F3 (bound to manganese oxides), F4 (bound to amorphous Fe minerals), F5 (bound to crystalline Fe minerals), F6 (oxidizable fraction-bound to organic matter and sulfides) and F7 (residual). The concentrations of the elements in these fractions from the new sequential extraction method were compared with the concentrations of the elements in the fractions obtained from the BCR sequential extraction method. A MANOVA test was used to find any inter-relationships between the fractions of these sequential extraction methods. It was concluded that the percentages of the elements extracted using the new sequential extraction method for the fractions F1 to F6 were generally higher than BCR sequential extraction method. This difference was probably related to the detailed fractionation capacity of the new sequential extraction method.

5.
J Interpers Violence ; 34(17): 3574-3591, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-30516451

RESUMO

The purpose of the study was to examine differences in sexual harassment attitudes between male and female labor force in health care organizations. A total of 571 employees working in various health care organizations in Turkey participated in the study. Sexual harassment was measured using 22 items and three-factor structure with constructs "Provocative Behavior," "Normal Flirtations," and "Trivial Matter" developed by Turgut. The data were collected using percentage, frequency, mean, standard deviation, independent sample t tests, and multivariate analysis of variance and covariance (MANOVA and MANCOVA). The results of the study revealed that a significant gender difference exists in sexual harassment attitudes with respect to "Provocative Behavior" and "Normal Flirtations" factors, while "Trivial Matter" factor was not statistically significant at the probability level of .05 as part of the sexual harassment scale. After controlling for variables such as age, marital status, monthly income level, education level, profession, institution, length of working time in the organization, and length of time in the health care sector; it was seen that most gender differences remained significant.


Assuntos
Atitude do Pessoal de Saúde , Pessoal de Saúde/psicologia , Assédio Sexual/psicologia , Percepção Social , Local de Trabalho/psicologia , Adulto , Fatores Etários , Feminino , Mão de Obra em Saúde , Humanos , Masculino , Estado Civil , Fatores Sexuais , Turquia , Adulto Jovem
6.
Environ Sci Pollut Res Int ; 25(3): 2672-2682, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29134525

RESUMO

Bream, anchovy, horse mackerel, sea bass, sardine, and whiting that are commonly consumed by the Turkish community were collected from the Marmara Sea in September and March and were analyzed for trace elements and for fat content. The total concentrations of some metals in these fish were determined using ICP-MS in acid extracts obtained after microwave digestion. The seasonal fat contents of the fish samples were determined gravimetrically following a Soxhlet extraction method. Experimental results were evaluated statistically using t tests and principal component analyses. This enabled the comparison of the elements' contents in the fish samples in March and September and also led to an investigation into whether or not there is a relationship between the elements' contents and the fat amount. The results of this work showed that a significant temporal difference was observed. This difference was not related to the seasonal variation in fat concentrations.


Assuntos
Monitoramento Ambiental/métodos , Peixes , Metais Pesados/análise , Alimentos Marinhos/análise , Oligoelementos/análise , Animais , Oceanos e Mares , Análise de Componente Principal , Medição de Risco , Estações do Ano , Turquia
7.
J AOAC Int ; 100(3): 712-716, 2017 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-28468698

RESUMO

A new, simple, efficient, and environmentally friendly ionic liquid dispersive liquid-liquid microextraction method was developed for the determination of irinotecan, an anticancer drug, in water and urine samples using UV-Vis spectrophotometry. The ionic liquid 1-hexyl-3-methylimidazolium hexafluorophosphate was used as the extraction solvent, and ethanol was used as the disperser solvent. The main parameters affecting the extraction efficiency, including sample pH, volume of the ionic liquid, choice of the dispersive solvent and its volume, concentration of NaCl, and extraction and centrifugation times, were investigated and optimized. The effect of interfering species on the recovery of irinotecan was also examined. Under optimal conditions, the LOD (3σ) was 48.7 µg/L without any preconcentration. Because the urine sample was diluted 10-fold, the LOD for urine would be 487 µg/L. However, this could be improved 16-fold if preconcentration using a 40 mL aliquot of the sample is used. The proposed method was successfully applied to the determination of irinotecan in tap water, river water, and urine samples spiked with 10.20 mg/L for the water samples and 8.32 mg/L for the urine sample. The average recovery values of irinotecan determined were 99.1% for tap water, 109.4% for river water, and 96.1% for urine.


Assuntos
Antineoplásicos Fitogênicos/análise , Antineoplásicos Fitogênicos/urina , Camptotecina/análogos & derivados , Microextração em Fase Líquida , Poluentes Químicos da Água/análise , Camptotecina/análise , Camptotecina/urina , Líquidos Iônicos , Irinotecano , Espectrofotometria , Água
8.
Food Chem ; 220: 242-248, 2017 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-27855895

RESUMO

A novel, simple, rapid, sensitive, inexpensive and environmentally friendly dispersive liquid-liquid microextraction method based on the solidification of a floating organic drop (DLLME-SFO) was developed for the determination of copper by flame atomic absorption spectrometry (FAAS). N-o-Vanillidine-2-amino-p-cresol was used as a chelating ligand and 1-undecanol was selected as an extraction solvent. The main parameters affecting the performance of DLLME-SFO, such as sample pH, volume of extraction solvent, extraction time, concentration of the chelating ligand, salt effect, centrifugation time and sample volume were investigated and optimized. The effect of interfering ions on the recovery of copper was also examined. Under the optimum conditions, the detection limit (3σ) was 0.93µgL-1 for Cu using a sample volume of 20mL, yielding a preconcentration factor of 20. The proposed method was successfully applied to the determination of Cu in tap, river and seawater, rice flour and black tea samples as well as certified reference materials.


Assuntos
Cobre/análise , Microextração em Fase Líquida/métodos , Espectrofotometria Atômica , Benzaldeídos/química , Quelantes/química , Cresóis/química , Água Potável/química , Farinha/análise , Análise de Alimentos , Concentração de Íons de Hidrogênio , Limite de Detecção , Oryza/química , Rios/química , Água do Mar/química , Chá/química
9.
Anal Chim Acta ; 935: 1-29, 2016 09 07.
Artigo em Inglês | MEDLINE | ID: mdl-27543012

RESUMO

This review discusses and compares the methods given for the determination of rare earth elements (REE) in natural water samples, including sea, river, lake, tap, ground and waste waters as well as Antarctic ice. Since REE are at very low concentrations in natural waters, numerous different preconcentration methods have been proposed to enable their measurement. These include liquid liquid extraction, dispersive liquid-liquid micro-extraction and solidified floating drop micro-extraction. In addition to liquid-liquid extraction methods, solid phase extraction using commercial resins, resins made in-house, silica-based exchange materials and other solid media is also discussed. These and other techniques such as precipitation/co-precipitation and flotation are compared in terms of speed, preconcentration factors achieved, precision, accuracy and limits of detection (LOD). Some papers have discussed the direct determination of REE in these sample types. Some have used specialised sample introduction systems such as ultrasonic nebulization whereas others have used a standard sample introduction system coupled with inductively coupled plasma mass spectrometry (ICP-MS) detection. These direct methods have also been discussed and compared.

10.
J AOAC Int ; 99(5): 1356-62, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27458174

RESUMO

In the present study, the simultaneous preconcentration of copper and cadmium based on dispersive liquid-liquid microextraction as a prior step to their determination using flame atomic absorption spectrometry was developed. Carbon tetrachloride and N,N'-bis(2-hydroxy-5-bromo-benzyl)1,2 diaminopropane were used as the extraction solvent and chelating ligand, respectively. Some parameters that influence the extraction efficiency-e.g., sample pH, volume of extraction solvent (carbon tetrachloride), concentration of the chelating ligand, effect of salt addition, and sample volume-were investigated and optimized. With a preconcentration factor of 10, the LODs (3σ) for Cd and Cu were 0.69 and 1.98 µg/L, respectively. The accuracy of the developed method was evaluated by analyzing SLRS-5 river water and SRM 1573a tomato leaves certified reference materials. Results obtained were in good agreement with the certified values. The proposed method was successfully applied to river water, seawater, and black tea samples. Good spike recoveries, varying within the range of 97.5 to 116.9%, confirmed the good performance of the method in real sample analysis.


Assuntos
Cádmio/análise , Cobre/análise , Diaminas/química , Microextração em Fase Líquida , Fenóis/química , Espectrofotometria Atômica , Rios/química , Água do Mar/química , Chá/química , Poluentes Químicos da Água/química
11.
J AOAC Int ; 2016 Dec 16.
Artigo em Inglês | MEDLINE | ID: mdl-28118131

RESUMO

A new, simple, efficient, and environmentally friendly ionic liquid dispersive liquid–liquid microextractionmethod was developed for the determination of irinotecan, an anticancer drug, in water and urine samples using UV-Vis spectrophotometry. The ionic liquid 1-hexyl-3-methylimidazolium hexafluorophosphate was used as the extraction solvent, and ethanol was used as the disperser solvent. The main parameters affecting the extraction efficiency, including sample pH, volume of the ionic liquid, choice of the dispersive solvent and its volume, concentration of NaCl, and extraction and centrifugation times, were investigated and optimized. The effect of interfering species on the recovery of irinotecan was also examined. Under optimal conditions, the LOD (3σ) was 48.7 μg/L without any preconcentration. Because the urine sample was diluted 10-fold, the LOD for urine would be 487 μg/L. However, this could be improved 16-fold if preconcentration using a 40 mL aliquot of the sample is used. The proposed method was successfully applied to the determination of irinotecan in tap water, river water, and urine samples spiked with 10.20 mg/L for the water samples and 8.32 mg/L for the urine sample. The average recovery values of irinotecan determined were 99.1% for tap water, 109.4% for river water, and 96.1% for urine.

12.
Talanta ; 144: 219-25, 2015 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-26452813

RESUMO

A new method for the extraction and preconcentration of trace elements (Al, Ba, Cd, Cu, Fe, Mn, Mo, Ni, Ti, V and Zn) from edible oils by producing detergentless micro-emulsions via an ultrasound-assisted extraction using a water phase containing Lipase at pH 3 as an extractant was developed. The trace elements in the water phase post-extraction were determined against matrix matched standards using ICP-MS. In the first step of the work, the parameters that affect extraction, such as pH, the volume of 1% lipase in the water phase and the ultrasonic and centrifugation times were optimized. Under the optimal conditions, the detection limits (µg kg(-1)) were 0.46, 0.03, 0.007, 0.028, 0.67, 0.038, 0.022, 0.14, 0.17, 0.05 and 0.07 for Al, Ba, Cd, Cu, Fe, Mn, Mo, Ni, Ti, V and Zn respectively for edible oils (3 Sb/m). A certified reference material (EnviroMAT HU-1 Used oil) was analysed to check the accuracy of the developed method. Results obtained were in agreement with certified values with a t-test showing that no significant differences at the 95% confidence levels were found. The proposed method was applied to different edible oils such as sunflower oil, rapeseed oil, olive oil and salmon oil.


Assuntos
Óleos de Peixe/análise , Lipase/química , Metais/análise , Metais/química , Óleos de Plantas/análise , Animais , Óleos de Peixe/química , Óleos de Plantas/química , Salmão , Sonicação
13.
Food Chem ; 188: 143-8, 2015 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-26041176

RESUMO

The aim of this study is to develop a new method for the extraction and preconcentration of trace elements from edible oils via an ultrasound-assisted extraction using ethylenediaminetetraacetic acid (EDTA) producing detergentless microemulsions. These were then analyzed using ICP-MS against matrix matched standards. Optimum experimental conditions were determined and the applicability of the proposed ultrasound-assisted extraction method was investigated. Under the optimal conditions, the detection limits (µg kg(-1)) were 2.47, 2.81, 0.013, 0.037, 1.37, 0.050, 0.049, 0.47, 0.032 and 0.087 for Al, Ca, Cd, Cu, Mg, Mn, Ni, Ti, V and Zn respectively for edible oils (3Sb/m). The accuracy of the developed method was checked by analyzing certified reference material. The proposed method was applied to different edible oils such as sunflower seed oil, rapeseed oil, olive oil and cod liver oil.


Assuntos
Emulsões/química , Óleos de Plantas/química , Oligoelementos/isolamento & purificação , Óleo de Fígado de Bacalhau/química , Ácido Edético , Oligoelementos/análise , Ultrassom
14.
Spectrochim Acta A Mol Biomol Spectrosc ; 147: 158-62, 2015 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-25835378

RESUMO

The present work describes a selective, rapid and economical spectrophotometric method for the determination of molybdenum using N,N'-bis(2-hydroxy-5-bromo-benzyl)1,2 diaminopropane. Molybdenum(VI) reacts with N,N'-bis(2-hydroxy-5-bromo-benzyl)1,2 diaminopropane to form a stable 1:1 yellow complex with an absorption maximum at 342 nm. The reaction is completed within 10 min and the absorbance of the molybdenum complex remains stable for at least 1 week at room temperature. The effective molar absorption coefficient at 342 nm was 9.6 × 10(3)L mol(-1)cm(-1). Under optimal conditions, the complex obeys Beer's law from 0 to 9.9 µg mL(-1). The relative standard deviation was 0.08% (for 11 samples, each containing 6 µg mL(-1) molybdenum). Under the optimum conditions, the detection limit (3σ) was 17.7 µg L(-1) for molybdenum without any preconcentration. The precision was determined from 30 results obtained for 4.80 µg mL(-1) Mo(VI); the mean value of a molybdenum(VI) was 4.83 µg ml(-1) with a standard derivation of 0.002 µg ml(-1) molybdenum(VI).


Assuntos
Compostos de Benzil/química , Diaminas/química , Molibdênio/análise , Rios/química , Espectrofotometria/métodos , Halogenação , Limite de Detecção
15.
Talanta ; 134: 476-481, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25618696

RESUMO

A new, simple, efficient and rapid separation method based on ligandless-dispersive liquid-liquid microextraction (LL-DLLME) was developed for the preconcentration of rare earth elements (REEs) (La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu) in natural water samples, followed by inductively coupled plasma mass spectrometry (ICP-MS) detection. Carbon tetrachloride and acetone were used as extraction solvent and disperser solvent, respectively. The experimental parameters affecting the extraction efficiency such as sample pH, volume of extraction/disperser solvent and concentration of NaCl were investigated and optimized. Under the optimum conditions, detection limits between 0.68 and 26.6 ng L(-1) for a 5 mL sample volume were determined. The developed method was successfully applied to samples such as tap water, river water and seawater. Satisfactory recoveries were obtained with the percentage recovery values of the REEs for spiked water samples being between 94 and 111 for tap water, between 89 and 118 for river water and between 92 and 124 for seawater.

16.
Artigo em Inglês | MEDLINE | ID: mdl-25058626

RESUMO

Seventeen trace metals in acid digests of nuts and seeds were determined using inductively coupled plasma-atomic emission spectrometry and inductively coupled plasma-mass spectrometry. The data were subjected to chemometric evaluation using principal component analysis (PCA), linear discriminant analysis (LDA) and cluster analysis (CA) in an attempt to classify the samples. Hazelnuts (raw and dry roasted), almonds (raw and dry roasted), sunflower seeds (black and white), peanuts (raw and dry roasted), cashew nuts, Brazil nuts, walnuts, chickpeas (raw and dry roasted), pumpkin seeds (raw and dry roasted), and pistachio nuts were used as samples. The samples were classified into seven groups by PCA and CA. All group members determined using PCA and CA were found by LDA to be correctly classified in the predicted groups. Interestingly, the chemometric evaluation indicated that the raw and roasted nuts are very close to each other even though some originated from different countries.


Assuntos
Análise de Alimentos , Metais/química , Sementes/química , Oligoelementos/química , Humanos , Análise de Componente Principal
17.
Food Chem ; 157: 70-6, 2014 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-24679753

RESUMO

Concentrations of the total aflatoxin, aflatoxin B1, aflatoxin B2, aflatoxin G1, aflatoxin G2, ochratoxin A, lead, cadmium, mercury, arsenic, copper, zinc and chromium in corn flour samples were determined. Eighteen corn flour samples that were obtained from different cities and villages in Turkey and 3 corn flour samples obtained from the UK. Determination of the different toxins was carried out using HPLC instrumentation after pre-separation using immunoaffinity columns that work through a mechanism of solid-phase extraction. An ICP-MS instrument was used for the heavy metal determinations. The results obtained from HPLC and ICP-MS analyses of the corn flour samples showed that these samples contain detectable levels of most of the analytes but the mercury was at undetectable levels. A very strong statistical relationship was observed between Cr and total Aflatoxin and Aflatoxin B1; whereas Ochratoxin A was related to Cu and Zn concentrations using correlation analyses and principal component analyses.


Assuntos
Aflatoxina B1/análise , Metais Pesados/análise , Ocratoxinas/análise , Aflatoxinas/análise , Cromatografia Líquida de Alta Pressão , Farinha/análise , Contaminação de Alimentos/análise , Análise de Componente Principal , Turquia , Zea mays
18.
Water Sci Technol ; 69(2): 312-9, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24473300

RESUMO

A new method has been developed for the determination of rare earth elements (REEs) (Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu) in water samples based on preconcentration with a mini-column packed with 6-(2-thienyl)-2-pyridinecarboxaldehyde functionalized Amberlite XAD-4 resin prior to their determination using inductively coupled plasma optical emission spectrometry (ICP-OES). The optimum experimental parameters for preconcentration of REEs, such as pH of the sample, sample and eluent flow rates and sample volume, were investigated. The optimum pH values for quantitative (90-110%) sorption of the REE ions were between 6.0 and 8.0. The elution process was carried out using 2 mL of 1.0 mol L(-1) HNO3 solution. Under the optimum conditions, detection limits between 0.032 and 0.963 µg L(-1) for a 10 mL sample volume and 0.006 and 0.193 µg L(-1) for a 50 mL sample volume were determined. The proposed method was successfully applied to the determination of REEs in water samples with recoveries in the range of 90.1-110.5%.


Assuntos
Metais Terras Raras/química , Poliestirenos/química , Polivinil/química , Resinas Sintéticas/química , Água/química
19.
Food Chem ; 141(2): 655-61, 2013 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-23790831

RESUMO

The synthesis and characterization of the resin Amberlite XAD-4 functionalized with 2,6-pyridinedicarboxaldehyde and its application in an on-line system for the preconcentration of cadmium, cobalt, copper, lead and manganese prior to determination using flame atomic absorption spectrometry (FAAS) is proposed. Metal ions retained on the modified resin were eluted using 1.0 mol L(-1) HNO3 solution and aspirated directly to the nebulizer-burner system of a FAAS instrument using a flow injection system. Detection limits (3σ) were determined to be 0.13 µg L(-1) for Cd, 0.29 µg L(-1) for Cu, 0.23 µg L(-1) for Mn, 0.58 µg L(-1) for Co and 2.19 µg L(-1) for Pb using a 10 mL of water sample loading volume. The limits of detection would be 100 times higher with units of µg kg(-1) for the solid samples in which their dilution ratios as (volume/weight) were 100. Enrichment factors ranged from 23.6 to 28.9 (for Co and Mn, respectively). The proposed method was successfully applied to determination of the analytes in natural water samples and certified reference materials.


Assuntos
Automação/métodos , Grão Comestível/química , Contaminação de Alimentos/análise , Resinas Sintéticas/química , Extração em Fase Sólida/métodos , Oligoelementos/isolamento & purificação , Poluentes Químicos da Água/isolamento & purificação , Automação/instrumentação , Polímeros/síntese química , Polímeros/química , Resinas Sintéticas/síntese química , Extração em Fase Sólida/instrumentação , Espectrofotometria Atômica/métodos , Oligoelementos/análise , Poluentes Químicos da Água/análise
20.
Environ Sci Pollut Res Int ; 19(4): 1280-95, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22081370

RESUMO

INTRODUCTION: A chemometric evaluation has been done to classify metal ions in soils and to determine whether or not the gastric and intestinal phases of a physiologically based extraction test bear any relation to any of the phases of the four-stage Community Bureau of Reference (BCR) extraction protocol. MATERIALS AND METHODS: Nine trace analytes (As, Ba, Cd, Cr, Cu, Mn, Ni, Pb and Zn) were determined in extracts obtained from the BCR sequential extraction procedure as well as from in vitro gastro-intestinal experiments. The results showed that high As, Pb, Zn and Cd concentrations were found in these soils. Principal component analysis (PCA) and linear discriminant analysis were used as classification techniques. Stepwise multiple linear regression analysis was applied to the data set to determine how the bioaccessibility of a metal is linked to the operationally defined fractions of metal speciation in soil. RESULTS AND DISCUSSION: This analysis showed that the metal concentrations in the intestinal and gastric extracts are mainly dependent on the concentrations found in BCR phases 1 and 2 for each metal ion except for Cr, which was mainly dependent on the concentrations found in BCR phase 3. From the chemometric technique of correlation analysis, it was concluded that the metals extracted using BCR phases 1 and 2 are more likely to be bioaccessible, i.e. are also extracted by gastric and intestinal digestion solutions. When the correlation and PCA results were interpreted together, it indicated that the bioaccessiblity of Zn, Pb, Mn and Cd were higher than As, Ba, Cr, Ni and Cu for these soils.


Assuntos
Exposição Ambiental , Trato Gastrointestinal/metabolismo , Medição de Risco/métodos , Poluentes do Solo/análise , Poluentes do Solo/farmacocinética , Arsênio/análise , Arsênio/farmacocinética , Disponibilidade Biológica , Técnicas de Química Analítica , Monitoramento Ambiental , Humanos , Metais/análise , Metais/farmacocinética , Turquia
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