RESUMEN
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
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
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
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.