RESUMEN
A qualitative study was carried out to explore the health status of people with diabetes during Ramadan. Fifteen patients participated in two focus group discussions. Most respondents reported lack of knowledge regarding their own conditions and do not follow the medical advice of not fasting during Ramadan. Barriers facing the patients seeking healthcare before and during Ramadan were the atmosphere, long distances to facilities, monthly appointments, and monthly prescribed medication. All respondents agreed on the importance of physical activity but their opinions varied on how to conduct it. Regarding the services, most respondents were unsatisfied due to the lack of health services provided in addition to the shortage of essential medication or laboratory investigations. Others blamed primary healthcare-center staff for the delay in laboratory investigation results and the unavailability of glycosylated hemoglobin (HbA1c). Respondents also claimed that self-check glucometer measurements are not as accurate as laboratory results. Doctors may be able to educate patients regarding the effects of fasting with diabetes whereas religious leaders may influence individuals to follow doctors' advice. Evaluation of the quality of healthcare services is necessary to identify defects in health services in order to ameliorate service quality, including availability of drugs and glucometers in pharmacies, and laboratory investigations, including HbA1c, to meet patient satisfaction.
Asunto(s)
Diabetes Mellitus/terapia , Ayuno , Conocimientos, Actitudes y Práctica en Salud , Adolescente , Adulto , Anciano , Consejo Dirigido , Femenino , Grupos Focales , Humanos , Islamismo , Masculino , Persona de Mediana Edad , Investigación Cualitativa , Arabia Saudita , Adulto JovenRESUMEN
In the present study, milk samples including raw and ultra-high temperature (UHT) processed milk were analyzed for pesticide residue levels, including five pesticides, viz chloripyrifos, endosulfan (α and ß), profenofos and bifenthrin by gas chromatography microelectron capture detector (GC-µECD) after extraction by QuEChERS method. Further confirmation of the pesticide residue was done by GC-MS. The pesticide residual level in raw and UHT milk samples (n = 70) was determined in the range of 0.1-30 µg L(-1). All UHT processed milk samples contain pesticide residues within permissible limit set by the World Health Organization (WHO); however, among raw milk samples, chloripyrifos (12 %), α (24 %), and ß (14 %) endosulfan were found above the maximum residue limit (MRL). The estimated daily intake (EDI) of these four pesticide residues were also calculated as 1.32, 16.16, 5.30, 10.20, and 9.93 µg kg(-1) body weight for chloripyrifos, endosulfan α, profenofos, endosulfan ß, and bifenthrin, respectively. It is concluded that the raw milk samples showed higher prevalence of pesticide residues as compared to UHT processed milk. Graphical abstract Determination of pesticide residues in dairy milk by GC-µECD after QuEChERS extraction method.
Asunto(s)
Contaminantes Ambientales/análisis , Leche/química , Residuos de Plaguicidas/análisis , Animales , Fraccionamiento Químico/métodos , Cromatografía de Gases/métodos , Endosulfano/análisis , Monitoreo del Ambiente , Contaminación de Alimentos/análisis , Cromatografía de Gases y Espectrometría de Masas/métodos , Calor , Plaguicidas/análisis , PiretrinasRESUMEN
Cigarette smoking causes an acute increase in blood pressure and heart rate and has been found to be associated with malignant hypertension (HT). A significant flux of toxic metals among other toxins reaches the lungs through smoking. In the present study, the relationship between essential (zinc and selenium) and toxic element (TE; cadmium and mercury) and HT incidence in smoker and nonsmoker population living in Dublin, Ireland was investigated. The zinc (Zn), selenium (Se), cadmium (Cd) and mercury (Hg) were determined in biological (scalp hair and blood) samples of smoker and nonsmoker hypertensive patients. For comparison purposes, healthy age- and sex-matched subjects as referents residing in the same city were also selected. The different brands of cigarette consumed by the studied population were also analyzed for Cd and Hg. The concentrations of essential trace and TEs in all studied samples were measured by inductively coupled plasma atomic emission spectrophotometer after microwave-assisted acid digestion. The validity and accuracy of the methodology was checked using certified reference materials (CRMs). The recovery of all the studied elements was found to be in the range of 96.4-99.7% of certified values of CRMs. The filler tobacco of different branded cigarettes contains Hg and Cd concentrations in the range of 9.55-12.4 ng and 1.70-2.12 µg per cigarette, respectively. The results of this study showed that the mean values of Cd and Hg were significantly higher in scalp hair and blood samples of hypertensive patients as compared with healthy controls, whereas Zn and Se concentrations were found to be lower in hypertensive patients, the difference was significant in the case of smoker patients (P < 0.001). The levels of both TEs were 2-3-folds higher in scalp hair and blood samples of nonhypertensive smoker subjects as compared with nonsmoker controls. It was observed that exposure of TEs via cigarette smoking may be synergistic with other risk factors associated with HT.
Asunto(s)
Cadmio/análisis , Cabello/efectos de los fármacos , Hipertensión/sangre , Mercurio/análisis , Selenio/análisis , Fumar , Productos de Tabaco , Zinc/análisis , Adulto , Femenino , Humanos , Hipertensión/psicología , Irlanda , Masculino , Factores de Riesgo , Fumar/efectos adversos , Fumar/sangre , Espectrofotometría Atómica/métodos , Productos de Tabaco/efectos adversos , Productos de Tabaco/análisis , Oligoelementos/análisisRESUMEN
The concentration of cadmium and zinc in vegetables was determined by using an online flame atomic absorption spectrophotometer after simultaneous pre-concentration based on the complexation of Cd and Zn with 1,5-diphenylthiocarbazone immobilised on naphthalene. The effect of pH, sample flow rate and amount of 1,5-diphenylthiocarbazone on adsorption was investigated. After pre-concentration, Cd and Zn were eluted from the sorbent with hydrochloric acid. A pre-concentration factor of 20 and 33 was achieved for Cd and Zn, respectively. The calibration curve was linear in the range of 0.2-1 µg ml(-1) for Cd and Zn. The regression coefficients for the lines were 0.9914 and 0.9989 for Cd and Zn, respectively. The detection limits were calculated as three times the standard deviation of nine replicates of blanks: 0.00123 µg ml(-1) for Cd and 0.00176 µg ml(-1) for Zn.
Asunto(s)
Cadmio/química , Contaminación de Alimentos/análisis , Naftalenos/química , Espectrofotometría Atómica/métodos , Verduras/química , Zinc/química , Ditizona/química , Análisis de los Alimentos/métodos , Concentración de Iones de Hidrógeno , Espectrofotometría Atómica/instrumentaciónRESUMEN
A simple and rapid non-chromatographic method was developed to determine methylmercury (MeHg) and inorganic mercury (iHg) levels in muscles tissues of 10 freshwater fish species. The MeHg and iHg were determined by cold vapour atomic absorption spectrometry after alkaline wet digestion of samples. The digested samples were reduced sequentially with stannous chloride and sodium tetrahydroborate for iHg and MeHg, respectively. Parameters such as carrier gas flow rate (argon), volume of oxidizing and potassium persulphate solutions were investigated in detail. The accuracy of the technique was evaluated by using certified reference material (DORM-2) and spiking the both Hg species in muscles tissue of a fish. The limits of detection were 0.117 and 0.133 µg kg(-1) for MeHg and iHg, respectively. The concentrations of MeHg and iHg in muscles tissues of ten fish species were found in the range of (28.4-56.3) and (3.01-8.11) µg kg(-1), respectively.
Asunto(s)
Mercurio/análisis , Compuestos de Metilmercurio/análisis , Músculo Esquelético/química , Espectrofotometría Atómica/métodos , Animales , Peces , Contaminantes Químicos del Agua/análisisRESUMEN
Cloud point extraction method has been developed for preconcentration of trace quantities of zinc (Zn) in aqueous extract of medicinal plants and blood samples of liver cancer patients using flame atomic absorption spectrometry. The Zn in aqueous extracts of medicinal plants (MPs) was complexed with 2-methyl-8-hydroxyquinoline (quinaldine) and 1-(2-pyridylazo)-2-naphthol (PAN) separately and entrapped in a non-ionic surfactant Triton X-114. After centrifugation, the surfactant-rich phase was diluted with 0.25mL acidic ethyl alcohol. The multivariate strategy was applied to estimate the optimum values of experimental variables (pH, time temperature, ligands and surfactant concentrations). Interactions between analytical factors and their optimal levels were investigated by two level factorial designs. Student's t-test on the results of factorial design with 16 runs for Zn extraction, demonstrated that the factors, ligands concentrations, pH and temperature were statistically significant. The accuracy was assessed by analysis of certified reference materials, namely, BCR 101 (spruce needles), Clincheck control-lyophilized human whole blood. Enhancement factor of 30 and 26 were achieved for the preconcentration of Zn by 2-methyl-8-hydroxyquinoline (L1) and 1-(2-pyridylazo)-2-naphthol (L2), respectively. The relative standard deviation for six replicate determinations of Zn at 10µg/L level using 2-methyl-8-hydroxyquinoline (L1) and 1-(2-pyridylazo)-2-naphthol (L2) were <4% and >5%, respectively.
Asunto(s)
Extracción Líquido-Líquido/métodos , Neoplasias Hepáticas/sangre , Extractos Vegetales/química , Plantas Medicinales/química , Espectrofotometría Atómica/métodos , Zinc/análisis , Adulto , Femenino , Humanos , Persona de Mediana Edad , Extractos Vegetales/aislamiento & purificación , Zinc/sangre , Zinc/aislamiento & purificaciónRESUMEN
A highly sensitive, simpler, faster and economical UV/visible spectrophotometric method has been established for the estimation of hydroquinone (HQ) in dilute organic matrices. The method is based on using ammonium meta-vanadate as an oxidizing catalyst for conversion of HQ to p-benzoquinone (BQ) in the presence of oxygen. As a result of higher absorption of UV light by BQ than by HQ, its signal has been utilized for determining HQ at the trace level. The effect of various parameters such as amount of oxidizing agent, stability time, temperature, acids and bases, solvents and interference by various compounds has been studied upon the absorption of BQ as HQ. Under optimized conditions, Beer's Law was obeyed in the range of 0.025-2.00 µg ml(-1) HQ at 245.5 nm using 1 : 1 (V/V) 2-propanol/water system with a lower detection limit of 7 ng ml(-1) and linear regression coefficient of 0.9998. Relative standard deviation of 1.5% was observed for 0.5 µg ml(-1) HQ solution (n = 11). The newly developed method has been successfully applied to diluted samples of various skin lightening creams for free HQ determination at the trace level. Comparison of the results obtained by the proposed method with those by a previously reported method proved its validity.
Asunto(s)
Cosméticos/química , Hidroquinonas/análisis , Espectrofotometría Ultravioleta/métodos , Humanos , Límite de Detección , Modelos LinealesRESUMEN
The chemical constituents in medicinal plants (MPs), including elements, are partially responsible for their medicinal and nutritional properties as well as toxic effects. This research aimed to monitor selenium (Se) contents in aqueous extract of MPs used for treatment of cancer and different diseases. In present work the Se in MPs was extracted in aqueous media by microwave-assisted (ME) and conventional extraction (CE) methods. The total and residual Se in MPs were determined, prior to microwave-assisted acid digestion. The Se in aqueous extracts and digests were analysed by electrothermal atomic absorption spectrometry. The optimum extractable Se in MPs were obtained by ME and CE, required 2 and 40 min, respectively. Precision and accuracy of the methodologies were checked by standard addition method. The Se contents in aqueous extract of MPs were found in the range of 1.09-2.23 µg/g corresponding to 21-33% of total Se contents. The daily intake of Se from aqueous extract of MPs as recommended by herbalist (10 g of plant material) was found in the range of 20-40% of daily requirement.
Asunto(s)
Antioxidantes/análisis , Neoplasias/tratamiento farmacológico , Plantas Medicinales/química , Selenio/análisis , Calibración , Dieta , Suplementos Dietéticos , Indicadores y Reactivos , Microondas , Extractos Vegetales/análisis , Espectrofotometría AtómicaRESUMEN
In this study, the contents of total mercury (Hg) present in poultry feed, tissues of broiler chicken and manure were assessed. For this purpose, chicken feeds (five brands), different tissues of broiler chicken of two age groups (1-3 and 4-6 week) and manure samples were collected from five commercial poultry farms of Hyderabad, Pakistan. The Hg concentrations in feeds, chicken tissues (leg, muscle, liver and heart) and manure samples were determined by CVAAS, prior to microwave assisted acid digestion in closed vessels. For validation, a certified reference material, DORM-2 was used. The limit of detection and quantitation were 0.117 and 0.382 microg/kg, respectively The Hg concentration in different chicken feed were found in the range of 8.57-16.5 microg/kg. The concentration of Hg in chicken tissues were found in the range of 2.54-5.54 microg/kg (liver), 1.27-3.86 microg/kg (muscles) and 2.13-3.27 microg/kg (heart). The bioaccumulation factors (BAF) for Hg in different tissues were found in the range of 0.092-0.269. The obtained data shows the high correlation coefficient between feed and manure, while low r-values were obtained between Hg levels in feed and tissues of broiler chicken of two age groups.
Asunto(s)
Alimentación Animal/análisis , Estiércol/análisis , Mercurio/análisis , Espectrofotometría Atómica/métodos , Animales , Pollos , Mercurio/farmacocinéticaRESUMEN
The objective of this study was to evaluate the association between trace and toxic elements zinc (Zn), cadmium (Cd), nickel (Ni) and lead (Pb) in biological samples (scalp hair, blood and urine) of smoker and nonsmoker hypertensive patients (n=457), residents of Hyderabad, Pakistan. For the purpose of comparison, the biological samples of age-matched healthy controls were selected as referents. The concentrations of trace and toxic elements were measured by atomic absorption spectrophotometer prior to microwave-assisted acid digestion. The validity and accuracy of the methodology were checked using certified reference materials and by the conventional wet acid digestion method on the same certified reference materials and real samples. The recovery of all the studied elements was found to be in the range of 97.8-99.3% in certified reference materials. The results of this study showed that the mean values of Cd, Ni and Pb were significantly higher in scalp hair, blood and urine samples of both smoker and nonsmoker patients than in referents (P<0.001), whereas the concentration of Zn was lower in the scalp hair and blood, but higher in the urine samples of hypertensive patients. The deficiency of Zn and the high exposure of toxic metals as a result of tobacco smoking may be synergistic with risk factors associated with hypertension.
Asunto(s)
Cadmio/análisis , Hipertensión/metabolismo , Plomo/análisis , Níquel/análisis , Fumar/metabolismo , Zinc/análisis , Adulto , Cadmio/sangre , Cadmio/orina , Femenino , Cabello/química , Humanos , Plomo/sangre , Plomo/orina , Masculino , Persona de Mediana Edad , Níquel/sangre , Níquel/orina , Zinc/sangre , Zinc/orinaRESUMEN
A cloud point extraction (CPE) method has been developed for the determination of total mercury (Hg) in different tissues of broiler chicken by cold vapor atomic absorption spectrometry (CVAAS). The broiler chicken tissues (leg, breast, liver and heart) were subjected to microwave assisted digestion in a mixture of nitric acid and hydrogen peroxide (2:1 ratio), prior to preconcentration by CPE. Various parameters such as the amount of ammonium O,O-diethyldithiophosphate (DDTP), concentrations of Triton X-114, equilibrium temperature, time and centrifugation have been studied in order to find the best conditions for the determination of mercury. For validation of proposed method a certified reference material, DORM-2 was used. No significant difference p>0.05 was observed between the experimental results and the certified values of CRM (paired t-test). The limit of detection and quantitation obtained under the optimal conditions were 0.117 and 0.382 microg/kg, respectively. The accumulation of Hg in different tissues were found in the order of, liver>muscles>heart. The concentration of Hg in chicken tissues were found in the range of 1.57-2.75, 1.40-2.27, 1.55-4.22, and 1.39-2.61 microg/kg in leg, breast, liver and heart, respectively.
Asunto(s)
Pollos/metabolismo , Mercurio/análisis , Animales , Calibración , Indicadores y Reactivos , Hígado/química , Músculo Esquelético/química , Miocardio/química , Pakistán , Valores de Referencia , Espectrofotometría Atómica , Tensoactivos/química , TemperaturaRESUMEN
A prevalence survey on hepatitis B and C infections was carried out to obtain national estimates and assess epidemiological dynamics and underlying risk factors. Overall prevalence of hepatitis B surface antigen (HBsAg) and anti-hepatitis C virus (HCV) of 2.5% and 4.8%, respectively, reflected a combined infection rate of 7.6% in the general population, consistent with an ongoing high burden of chronic liver disease (CLD). There was significant association of these viral infections with a range of risk factors led by reuse of syringes. These findings validate currently implemented strategies by the national programme for the control of hepatitis viral infections, including universal vaccination of newborns and high-risk groups, support of auto-disable syringes, promotion of infection control and patient safety, public health education, and management of needy CLD patients as a poverty-reduction health intervention.
Asunto(s)
Hepatitis B/epidemiología , Hepatitis C/epidemiología , Adolescente , Adulto , Niño , Preescolar , Femenino , Encuestas Epidemiológicas , Hepatitis B/prevención & control , Antígenos de Superficie de la Hepatitis B/sangre , Hepatitis C/prevención & control , Anticuerpos contra la Hepatitis C/sangre , Humanos , Lactante , Masculino , Persona de Mediana Edad , Pakistán/epidemiología , Prevalencia , Factores de Riesgo , Distribución por Sexo , Vacunación , Adulto JovenRESUMEN
Smokeless tobacco (ST), widely used in Pakistan, poses a high risk for oral cancer. Our hospital-based data illustrate that oropharyngeal cancer (9.9%) is the second leading malignancy after breast cancer (16.1%), and is significantly higher than in other Member States of the World Health Organization's Eastern Mediterranean Region. Urdu-speaking communities had a proportionately higher rate of oropharyngeal cancer (20.4%), followed by Balochis (19.9%), Sindhis (16.8%), Punjabis (11.7%) and Pashtuns (9.6%). Association of oropharyngeal cancer with ST use was four times higher relative to no history of tobacco use after adjustingfor age, ethnicity and gender. Our findings also show a predominance of this cancer among males relative to females and one-third of the reported cases occurred among individuals under 40 years. These findings have significant social impact, indicating the need for urgent intervention against the use of ST.
Asunto(s)
Neoplasias Orofaríngeas/etiología , Tabaco sin Humo/efectos adversos , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Niño , Preescolar , Femenino , Humanos , Lactante , Masculino , Persona de Mediana Edad , Análisis Multivariante , Neoplasias/epidemiología , Neoplasias Orofaríngeas/epidemiología , Pakistán/epidemiología , Adulto JovenRESUMEN
Smokeless tobacco [ST], wtclefy used in Pakistan, poses a high risk for oral cancer. Our hospital-based data illustrate that oropharyngeal cancer [9.9%] is the second leading malignancy after breast cancer [16.1%], and is significantly higher than in other Member States of the World Health Organization's Eastern Mediterranean Region. Urdu-speaking communities had a proportionately higher rate of oropharyngeal cancer [20.4%], followed by Balochis [19.9%], Sindhis [16.8%], Punjabis [11.7%] and Pashtuns [9.6%]. Association of oropharyngeal cancer with ST use was four times higher relative to no history of tobacco use after adjusting for age, ethnicity and gender. Our findings also show a predominance of this cancer among males relative to females and one-third of the reported cases occurred among individuals under 40 years. These findings have significant social impact, indicating the need for urgent intervention against the use of ST
Asunto(s)
Neoplasias Orofaríngeas , Factores de Riesgo , Tabaco sin HumoRESUMEN
The determination of trace and toxic elements in biological samples (blood, urine and scalp hair samples) of human beings is an important clinical test. The aim of our present study was to determine the concentration of arsenic (As), copper (Cu), cobalt (Co) and manganese (Mn), in biological samples of male production workers (PW) and quality control workers (QW) of steel mill, with aged 25-55 years, to assess the possible influence of environmental exposure. For comparison purpose, the same biological samples of unexposed healthy males of same age group were collected as control subjects. The determination of all elements in biological samples was carried out by electrothermal atomic absorption spectrometry, prior to microwave assisted acid digestion. The accuracy of the As, Cu, Co and Mn measurements was tested by simultaneously analyzing certified reference materials (CRMs) and for comparative purposes conventional wet acid digestion method was used on the same CRMs. No significant differences were observed between the analytical results and the certified values, using both methods (paired t-test at P > 0.05). The results indicate that concentrations of As, Cu, Co and Mn in all three biological samples of the exposed workers (QW and PW) were significantly higher than those of the controls. The possible correlation of these elements with the etiology of different physiological disorders is discussed. The results were also demonstrated the need of attention for improvements in workplace, ventilation and industrial hygiene practices.
Asunto(s)
Arsénico/metabolismo , Metalurgia , Metales Pesados/metabolismo , Exposición Profesional/efectos adversos , Espectrofotometría Atómica/métodos , Adulto , Arsénico/análisis , Cobalto/análisis , Cobalto/metabolismo , Cobre/análisis , Cobre/metabolismo , Cabello/química , Humanos , Masculino , Manganeso/análisis , Manganeso/metabolismo , Metales Pesados/análisis , Persona de Mediana Edad , AceroRESUMEN
Multivariate statistical techniques, cluster analysis (CA) and principal component analysis (PCA) were applied to the data on water quality of Manchar Lake (Pakistan), generated during 2005-06, with monitoring at five different sites for 36 parameters. This study evaluated and interpreted complex water quality data sets and apportioned of pollution sources to get better information about water quality and to design a monitoring network. The chemical correlations were observed by PCA, which were used to classify the samples by CA, based on the PCA scores. Three significant sampling locations--(sites 1 and 2), (site 4) and (sites 3 and 5)--were detected on the basis of similarity of their water quality. The results revealed that the major causes of water quality deterioration were related to inflow of effluent from industrial, domestic, agricultural and saline seeps into the lake at site 1 and also resulting from people living in boats and fishing at sites 2 and 3.
Asunto(s)
Monitoreo del Ambiente/métodos , Agua Dulce/química , Medición de Riesgo/métodos , Contaminantes del Agua/análisis , Abastecimiento de Agua/análisis , Abastecimiento de Agua/normas , Análisis por Conglomerados , Monitoreo del Ambiente/estadística & datos numéricos , Pakistán , Análisis de Componente Principal , Medición de Riesgo/estadística & datos numéricosRESUMEN
It was extensively investigated that a significant flux of toxic metals, along with other toxins, reaches the lungs through smoking. In present study toxic metals (TMs) (Al, Cd, Ni and Pb) were determined in different components of Pakistani local branded and imported cigarettes, including filler tobacco (FT), filter (before and after normal smoking by a single volunteer) and ash by electrothermal atomic absorption spectrometer (ETAAS). Microwave-assisted digestion method was employed. The validity and accuracy of methodology were checked by using certified sample of Virginia tobacco leaves (ICHTJ-cta-VTL-2). The percentages (%) of TMs in different components of cigarette were calculated with respect to their total contents in FT of all branded cigarettes before smoking, while smoke concentration has been calculated by subtracting the filter and ash contents from the filler tobacco content of each branded cigarette. The highest percentage (%) of Al was observed in ash of all cigarettes, with range 97.3-99.0%, while in the case of Cd, a reverse behaviour was observed, as a range of 15.0-31.3% of total contents were left in the ash of all branded cigarettes understudy.
Asunto(s)
Electrones , Metales/análisis , Metales/toxicidad , Nicotiana/química , Espectrofotometría Atómica/métodos , Temperatura , Microondas , PakistánRESUMEN
The aim of present study was to develop a database of arsenic (As) in lake water, ground water, sediment, soil, vegetables, grain crops and fish to evaluate the potential human health risks posed by higher level of As, in south east part of Sindh, Pakistan during 2005-2007. The total concentration of As in various samples under study was determined by electrothermal atomic absorption spectrophotometry (ETAAS). The reliability and accuracy of technique was checked by different certified reference materials. The concentration of As in lake and ground water samples exceeded the WHO guideline values. The concentration of As in lake sediment and agricultural soil samples ranged between 11.3-55.8 and 8.7-46.2 mg/kg while acid soluble As (acetic acid 0.11 mol/L) was observed in the range of 1.48-3.54 and 0.34-3.78 mg/kg, respectively. It was observed that the leafy vegetables (spinach, coriander and peppermint) contain higher As levels (0.90-1.20 mg/kg) as compared to ground vegetables (0.048-0.25) and grain crops (0.248-0.367 mg/kg) on dried weight basis. The estimated daily intake of total As in the diet was 9.7-12.2 microg/kg body weight/day.
Asunto(s)
Arsénico/análisis , Dieta , Contaminación de Alimentos/análisis , Agua Dulce/química , Sedimentos Geológicos/química , Animales , Grano Comestible/química , Peces , Análisis de los Alimentos , Humanos , Pakistán , Verduras/químicaRESUMEN
The mobility, availability and persistence of heavy metals (Cd, Cr, Cu, Ni, Pb and Zn) in contaminated lake sediment samples were evaluated by means of sequential extraction scheme, proposed by the Community Bureau of Reference protocol (BCR). The metal content in the extracts was measured by atomic absorption spectrometry. The precision and accuracy of the proposed procedure were evaluated by using a certified reference material BCR 701. The maximum recoveries for heavy metals (HMs) were observed for all three steps of BCR protocol at 32h total shaking period instead of previously reported 51h, with p>0.05. The lixiviation tests (DIN 38414-S4) were used to evaluate the leaching of HMs from sediment samples and it was observed that levels of water extractable HMs were low as compared to those values obtained by acid-soluble fraction of the BCR protocol.
Asunto(s)
Sedimentos Geológicos/análisis , Metales Pesados/análisis , Contaminantes Químicos del Agua/análisis , Contaminación Química del Agua/análisis , Ácidos , Agua Dulce/análisis , Indicadores y Reactivos , Microondas , Estándares de Referencia , Espectrofotometría AtómicaRESUMEN
The concentrations of 15 elements were determined in water, sediment and tissues of fish (Oreochromis mossambicus) collected from five sampling stations of Manchar Lake in 2005 for two successive seasons, winter (WS) and summer (SS). Elements analysis was performed by atomic absorption spectrometry with flame (FAAS) and electrothermal (ETAAS) modes, using multielement standard solution. The obtained results show that, the trace and toxic elements (As, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb and Zn) and macronutrients (Al, Ca, K, Mg and Na) concentrations in lake water were above the recommended drinking water standards by WHO. Concentrations of Na detected in lake water in WS and SS, were in the range of 445.5-562.7 and 420.6-643.5 mgl(-1), respectively. While among toxic elements As concentration in both seasons, have been found in the range of 60.4-88.9 and 64.9-101.8 microgl(-1) respectively, these values are 6-10 times higher than the permissible limit of WHO. The mean concentrations of elements understudy in muscles of fish were found as 2.35, 1.39, 0.46, 2.3, 1517.9, 2.2, 2.4 and 188.9 mgkg(-1) for As, Cd, Cr, Cu, Fe, Ni, Pb and Zn, respectively. High accumulation of toxic elements in fish tissues is indicating that some of the metal contaminants are entering the food chain. Correlations among the variables were identified by multivariate analysis. The extraction of elements from sediments with EDTA, to predict the bioavailability of trace and toxic elements, has shown that among them As, Cd and Zn were the most bioavailable elements in lake sediment.