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1.
The content of Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn was determined in commercially available black and green tea from Sarajevo market. The concentrations of metals in tea infusion and solutions prepared by applying four digestion methods were determined by using FAAS. The results show that the highest concentration of total metals was obtained after acid digestion in an autoclave. The concentration of metals soluble in water obtained in tea infusion does not exceed maximum allowed values provided by WHO (Guidelines for drinking-water quality, World Health Organization, Geneva, 2011). Among the investigated metals Mn was the highest and ranged from 286 to 334 μg g?1 in tea infusion of green and black tea, respectively, to 1,078 and 1,528 μg g?1 total content of Mn in green and black tea, respectively. The concentration of heavy metals in water extracts of tea was distinctly low in comparison with the total content. The concentrations of Cd and Pb were under the determination limit using FAAS. The total content of all determined metals was higher in black tea than in green tea.  相似文献   

2.
Contents of various elements in dyferent parts of the tea plant (shoot, mature leaf, small stem, thick wood and root), black tea manufactured by the crush-tear-curl and orthodox processes, and tea brew after 1 and 5 min of infusion were determined by inductively coupled plasma atomic emission spectrometry. From these, the amount of each element assimilated in the production of 1000 kg of marketable tea, as well as the quantity of each element brought into infusion and thus possib f y taken up through drinking tea, were calculated and discussed. Among the various elements assimilated by the tea plant, the shoot jraction (economically important for manufacturing commercial tea) contained high concentrations of N, P, K and Mg while the mature leaf accumulated Al, Bu, Ca, Cd, Mn, Pb and Sr. Of the dgerent elements brought into infusion while brewing black tea, the amount of K was found to be the largest (> 10000 μg g−1 tea) followed by P (700–1200 μg g−1), Mg (300–700 μg g−1), Ca and A1 (each 150–300 μg−1), Mn (60–150 μg g−1), Cu, Na, Si and Z n (each 6–50 μg g−1), B, Ba, Cr, Fe, Ni and Pb (each Id μg g−1), and Sr, Co and Gd (each <1μg g−1). The proportion of the totalamount of an element brought into infusion showed that the elements Ba, Ca, Fe and Sr were less soluble (<10 % of total amount), Al, B, Cd, Co, Cr, Cu, Mg, Mn, P, Pb, Si and Zn were moderately soluble (10–50 %), and K, Nu and Ni were highly soluble (>50%). The overall mean of the extent of solubility of all elements in 1 and 5 min showed that, out of the amount soluble in 5 min, about 68% was dissolved within 1 min.  相似文献   

3.
This study deals with the determination of Cu, Al, Cd, Mo, Pb, V, Sr, Ni, Cr, Co, Zn, Mn, and Fe in tea, wheat grain, and wheat flour by inductively coupled plasma optical emission spectrometry (ICP OES) with axially viewed plasma. Ultrasonic nebulization (USN) or pneumatic nebulization with aerosol desolvation (PN/DES) is used to introduce the sample solution into the ICP. Solutions of nitric acid (HNO3) with different concentrations of the acid (4.6 to 9.1 mol L?1) and hydrogen peroxide (H2O2) were investigated for sample decomposition in closed vessel (made of TFM-polytetrafluoroethylene (PTFE)) under microwave irradiation. Certified reference materials of tea, wheat flour, or bush branches and leaves were analyzed (0.5 g of sample in the presence of 2 mL H2O2?+?3 mL HNO3?+?2 mL H2O). Element concentrations found were in accordance with those certified in most cases, excepting for Al and V. Plasma-related matrix effects were not observed as denoted by the signal of the Ar 420.069-nm emission line. The analyte recoveries in spiked chamomile tea and wheat flour samples ranged from 87 to 107 %. By using USN, the limits of quantification (LOQs) of Cu, Al, Cd, Mo, Pb, V, Sr, Ni, Cr, Co, Zn, Mn, and Fe were 0.033, 0.006, 0.023, 0.33, 2.0, 0.33, 0.001, 0.33, 0.07, 0.033, 0.07, 0.001, and 0.02 μg g?1, respectively. Quite similar LOQs were obtained for both nebulizers employed, with the exception of Pb; the LOQ of Pb was three times lower by using PN/DES. Commercialized tea, wheat grain, and wheat flour were analyzed, and the concentrations found were reported.  相似文献   

4.
Concentration levels of As, Cd, Hg, Pb, Tl, Sn, Sb Co, Cu, Mn, Se, Zn, Cr, Ni and Mo in different types of rice cultivated in irrigated fields in Brazil were evaluated. Arsenic, Cd, Pb, Zn, Mn and Cu were found in higher concentrations in brown rice samples, suggesting the prevalence of these elements in the bran. Meanwhile, lower concentrations of Pb, Mo, Cr, Se and Co were found in parboiled rice. Organic rice did not differ of cultivated conventionally rice. Thallium, Hg and Sb were not detected in any rice sample whose limits of detection were 0.7 μg kg?1, 2.5 μg kg?1 and 8 μg kg?1, respectively. The concentrations of the investigated elements were compared with those reported for polished rice and brown rice from other countries, unveiling concentrations in general at the same level for rice produced at non-contaminated sites.  相似文献   

5.
The objective of this study was to determine the seasonal and sexual effects on metal levels of lump crabmeat (LCM) and chela crabmeat (CCM) of mature Atlantic blue crabs, Callinectes sapidus, caught in the Mersin Bay, the north‐eastern Mediterranean. The findings indicated that the annual ranges of metal levels in the LCM of Atlantic blue crab were as follows: 0.44–0.61 μg Cd g?1, 0.30–0.60 μg Cr g?1, 0.24–0.52 μg Pb g?1, 9.72–43.70 μg Cu g?1, 39.52–97.26 μg Zn g?1, 11.97–32.48 μg Fe g?1. The annual range of metal levels in the CCM of Atlantic blue crab were as follows: 0.52–1.07 μg Cd g?1, 0.24–0.61 μg Cr g?1, 0.28–0.56 μg Pb g?1, 22.17–68.09 μg Cu g?1, 93.92–175.21 μg Zn g?1, 8.81–19.47 μg Fe g?1. Cd, Cu, Zn levels in CCM of Atlantic blue crabs were higher than in LCM, whereas Fe levels were found lower (P < 0.05). Fe metal specifically accumulated in LCM, and Cd, Cu and Zn metals accumulated in CCM. Metals such as Cu, Zn and Fe showed seasonal variations. It was found out that Cu, Zn and Fe levels of muscle tissues of the Atlantic blue crab in spring and summer seasons were higher than in autumn and winter seasons.  相似文献   

6.
In the present study, 20 inorganic elements in three parts of preserved eggs prepared with different metal ions, including Al, As, Ba, Ca, Cd, Co, Cr, Cu, Fe, Li, K, Mg, Mn, Mo, Na, P, Pb, Zn, Se, and Sr, were determined simultaneously by using inductively coupled plasma–atomic emission spectrometry (ICP-AES). The recoveries obtained by the standard addition method ranged between 84.4 and 112.2 %, and RSDs were lower than 8.76 %, The detection limits of the method for the 20 elements were in the range of 0.4–10 μg?L?1. The determination results showed that three parts of preserved eggs prepared with different metal ions are all rich in essential inorganic elements, such as Na, K, P, Ca, Mg, Fe, Cu, and Zn, and the contents of most of the inorganic elements in egg yolk are higher than in egg white. In comparison with fresh duck eggs, the contents of Na, Cu, Fe, Al, and Mn are significantly increased in three parts of preserved eggs prepared with different metal ions. Metal ions added in pickling solution would significantly affect the content of element added in preserved eggs. High contents of Pb (20.15 μg/g in egg shell, 18.99 μg/g in egg white, and 0.96 μg/g in egg yolk) were found in preserved eggs with PbO. Meanwhile, the experimental results indicated that the ICP-AES technique is easy to operate, rapid, accurate, and highly sensitive to determine many inorganic elements simultaneously in preserved egg.  相似文献   

7.
In this study, a total of 35 tree nut samples of walnut, pecan, pine seed, hickory nut and torreya were obtained from 5 farm product markets in Hangzhou, China, and investigated for essential (Cr, Mn, Fe, Mo, Cu, Zn, Se and Sr) and toxic (Al, As, Cd and Pb) elements by inductively coupled plasma–mass spectroscopy. Mean elemental concentrations of different tree nuts were in the following ranges: Cr 0.26–0.78 mg kg–1, Mn 42.1–174 mg kg–1, Fe 33.7–43.9 mg kg–1, Mo 0.11–0.48 mg kg–1, Cu 10.3–17.6 mg kg–1, Zn 21.6–56.1 mg kg–1, Se 0.015–0.051 mg kg–1, Al 1.44–37.6 mg kg–1, As 0.0062–0.047 mg kg–1, Cd 0.016–0.18 mg kg–1 and Pb 0.0069–0.029 mg kg–1. The estimated provisional tolerable daily intake of Al, As, Cd and Pb was much lower than the provisional tolerable daily intake.  相似文献   

8.
BACKGROUND: In this study, 18 kinds of medicinal plants were collected together with their soils from different regions of Turkey and their macro‐ and micro‐element and heavy metal contents were determined by inductively coupled plasma atomic emission spectrometry (ICP‐AES). In soils, pH, electrical conductivity, carbonate (lime), organic matter, texture, P, K, Ca, Mg, Fe, Cu, Mn, Zn and B were analysed. In plants and extracts, P, K, Ca, Mg, Fe, Cu, Mn, Zn, B, Na, Al, Li, Pb, Ni, Cd, Co and Cr contents were determined. Also, correlations between soil and plant and between plant and extract were established. RESULTS: Element concentrations ranged between 0.11 and 5160 µg g?1 in soil samples, between 0.14 and 54400 µg g?1 in plant samples and between 0.039 and 22033 µg g?1 in extract samples. While sage was rich in Fe (981.3 µg g?1), basil was abundant in P (9.8 mg g?1), K (54.4 mg g?1), Ca (22.6 mg g?1), Mg (3.1 mg g?1) and Zn (46.05 µg g?1) and mint was rich in Li (23.50 µg g?1). Moreover, while high levels of P (4100.9 µg g?1), K (22033 µg g?1) and Mg (529.15 µg g?1) were found in basil extract, Ca (5979.3 µg g?1) was present at high concentration in marjoram leaf extract. Also, Fe (4.25 µg g?1) and Zn (17.51 µg g?1) were detected at high levels in lime flower and mint extracts respectively. CONCLUSION: It was concluded that aromatic plants are important sources of nutrients and essential elements. Copyright © 2007 Society of Chemical Industry  相似文献   

9.
A practical method was described for determining Al, B, Co, Cr, Cu, Fe, Mg, Mn, Pb, and Zn in various vinegar samples using microwave induced plasma optical emission spectrometry (MIP OES). Prior to analysis, vinegar samples were diluted to appropriate volumes and then directly aspirated to the plasma. All determinations were performed using aqueous standards for calibration. The analytes added to the vinegar samples were recovered quantitatively (between 93 and 104 %). The LOD values for Al, B, Co, Cr, Cu, Fe, Mg, Mn, Pb, and Zn were 0.62, 7.67, 4.55, 0.52, 1.22, 5.72, 1.32, 0.35, 2.42, and 26.0 μg L?1, respectively. Finally, the analyte concentrations in various types of vinegar samples produced in Turkey were determined and found below maximum allowable values stated by the Turkish Food Codex.  相似文献   

10.
Heavy metals (As, Cd, Co, Cr, Cu, Mn, Ni, Pb and Zn) in various vegetables (cabbage, green onion, lettuce, parsley, rocket, spinach, carrot, onion, potato and cauliflower) from the market in Jordan were measured using inductively coupled plasma-mass spectrometry. As, Cd, Co, Cr, Cu, Mn, Ni, Pb and Zn ranged from 0.009–0.275 mg kg?1 wet weight, 0.004–0.060 mg kg?1, 0.003–0.401 mg kg?1, 0.105–3.51 mg kg?1, 0.15–1.15 mg kg?1, 0.93–14.39 mg kg?1, 0.044–0.702 mg kg?1, 0.072–0.289 mg kg?1 and 2.23–6.65 mg kg?1, respectively. Parsley, followed by spinach, contained the highest concentration of heavy metals. Onion contained high levels of toxic heavy metals. The content of Cu in parsley and spinach and Pb in onion exceeded the Codex limits. However, the daily intake of heavy metals from the tested vegetables was lower than the maximum limits for allowable intake.  相似文献   

11.
Toxic and nutrient elements were investigated in yerba mate (Ilex paraguariensis) from South America. Fifty-four brands of commercialised yerba mate from Argentina, Brazil, Paraguay and Uruguay were analysed for Al, Ba, Ca, Cu, Fe, K, Mg, Mn, P, Sr, and Zn, using inductively coupled plasma optical emission spectrometry (ICP-OES), and Li, Be, Ti, V, Cr, Ni, Co, As, Se, Rb, Mo, Ag, Cd, Sb, La, Ce, Pb, Bi and U using inductively coupled plasma mass spectrometry (ICP-MS). Antimony, Se, Ag and Bi were not detected in any sample whereas the limits of detection (LODs) of these elements were 0.19, 0.40, 0.003 and 0.001 μg g?1, respectively. Analysis of variance (ANOVA) revealed that the concentrations of Cd, Ti, Ni, As, Mo, U, Li and Be in yerba mate were not statistically different with regard to the country of origin, while those of the other investigated elements differed.  相似文献   

12.
BACKGROUND: Minerals are essential for human nutrition and must be obtained from our diet. Crucifer vegetables are a good source of these nutrients. Our objectives were to determine the genetic variability for mineral content and to evaluate the use of near‐infrared reflectance spectroscopy (NIRS) for prediction of ashes and minerals among and within the rocket species Eruca vesicaria subsp. sativa and vesicaria. The minerals studied were iron (Fe), copper (Cu), sodium (Na), potassium (K), calcium (Ca), magnesium (Mg), manganese (Mn) and zinc (Zn). RESULTS: The maximum mean values obtained for all the accessions (mean ± SE) were 235.5 ± 1.5 mg ashes kg?1, 273.3 ± 4.2 mg Fe kg?1, 18.1 ± 0.4 mg Cu kg?1, 2.8 ± 0.1 g Na kg?1, 71.6 ± 1.0 g K kg?1, 64.6 ± 1.2 g Ca kg?1, 6.8 ± 0.1 g mg kg?1, 101.6 ± 1.2 mg Mn kg?1, and 67.1 ± 0.4 mg Zn kg?1 of dry weight. CONCLUSION: The statistical analysis showed significant differences for all the minerals, except Ca, for each accession studied individually and for accessions grouped within countries. The results indicate that NIRS can be used as a rapid screening method for determining total mineral, Fe, Na, K, and Zn in rocket. Copyright © 2011 Society of Chemical Industry  相似文献   

13.
BACKGROUND: This paper deals with the biosorption process as a method of enrichment of natural biomass of the edible microalga Spirulina sp. with microelement metal ions, which is of significance in terms of animal nutrition. The influence of the following process parameters was studied for the biosorption of Cr(III): pH and biomass concentration on kinetics and equilibrium of biosorption. The enrichment process were performed in single‐ and multi‐mineral systems for nutritionally significant minerals such as Cu(II), Mn(II), Co(II), Zn(II) and Cr(III) under the conditions that were determined for Cr(III). RESULTS: The best operational parameters for the process were selected as pH 5 and Cs 1 g L?1. The maximum biosorption capacity 71.2 mg g?1, 18.4 mg g?1, 83.9 mg g?1, 31. 8 mg g?1 and 26.5 mg g?1, were reached for Cu(II), Mn(II), Co(II), Zn(II) and Cr(III), respectively. To cover 100% of animal demand on microelements, 4.91 g of the preparation for laying hens and 9 g for swine of enriched microalgae in the single‐metal system should be added to 1 kg of fodder. In the multi‐metal system the competition between microelements was high enough to make it impossible to reach a suitable ratio between bound metal ions. CONCLUSIONS: Two methods of production of mineral feed additives were proposed: a single‐metal system and a multi‐metal system. Performing the biosorption process in the single‐metal system enabled the preparation of additives with the desired composition. Carrying out biosorption in the multi‐metal system is easier, technologically, but the ratio of bound microelements is difficult to predict. Copyright © 2009 Society of Chemical Industry  相似文献   

14.
Pyrrolizidine alkaloids (PAs) are secondary metabolites of plant families such as Asteraceae or Boraginaceae and are suspected to be genotoxic carcinogens. Recent investigations revealed their frequent occurrence in honey and particularly in tea. To obtain a comprehensive overview of the PA content in animal- and plant-derived food from the European market, and to provide a basis for future risk analysis, a total of 1105 samples were collected in 2014 and 2015. These comprised milk and milk products, eggs, meat and meat products, (herbal) teas, and (herbal) food supplements collected in supermarkets, retail shops, and via the internet. PAs were detected in a large proportion of plant-derived foods: 91% of the (herbal) teas and 60% of the food supplements contained at least one individual PA. All types of (herbal) teas investigated were found to contain PAs, with a mean concentration of 460 µg kg?1 dry tea (corresponding to 6.13 µg L?1 in [herbal] tea infusion). The highest mean concentrations were found in rooibos tea (599 µg kg?1 dry tea, 7.99 µg L?1 tea infusion) and the lowest in camomile tea (274 µg kg?1 dry tea, 3.65 µg L?1 tea infusion). Occurrence of PAs in food supplements was found to be highly variable, but in comparable ranges as for (herbal) tea. The highest concentrations were present in supplements containing plant material from known PA-producing plants. In contrast, only 2% of the animal-derived products, in particular 6% of milk samples and 1% of egg samples, contained PAs. Determined levels in milk were relatively low, ranged between 0.05 and 0.17 µg L?1 and only trace amounts of 0.10–0.12 µg kg?1 were found in eggs. No PAs were detected in the other animal-derived products.  相似文献   

15.
Twenty-seven rice samples from Brazil, four parboiled brown, seventeen white and six parboiled white were analysed by ICP-MS for trace element determination. Concentrations of arsenic varied from 58.8 to 216.9?ng?g?1, for cadmium from 6.0 to 20.2?ng?g?1, for antimony from 0.12 to 1.28?ng?g?1, and for uranium from 0.025 to 1.28?ng?g?1. The estimated daily intake through rice consumption was 9.5?µg for As, 2.4?µg for Cd, 0.029?µg for Sb, 0.013?µg for U, 3.1?µg for Co, 0.2?µg for Cu, 85.6?mg for Mg, 1.9?mg for Mn, 333?mg for P, 3.0?µg for Se, 1.6?mg for Zn, 0.9?mg for Rb, and 0.3?µg for V. Found values represent a considerable percentage of the dietary reference intakes and provisional tolerable daily intake for essential and toxic elements, respectively.  相似文献   

16.
A survey of the levels of some essential and non-essential trace elements in different types of rice available on the Swedish retail market was carried out in 2001–03. The types of rice included long and short grain, brown, white, and parboiled white. The mean levels found were: chromium (Cr)?=?0.008 mg kg?1, copper (Cu)?=?1.9 mg kg?1, iron (Fe)?=?4.7 mg kg?1, manganese (Mn)?=?16 mg kg?1, platinum (Pt)?<?0.0003 mg kg?1, rubidium (Rb)?=?3.3 mg kg?1, selenium (Se) =0.1 mg kg?1; and zinc (Zn)?=?15 mg kg?1. Inductively coupled plasma-mass spectrometry (ICP-MS) was used for the determination of Pt, Rb, and Se, after acid digestion. All other elements were determined using atomic absorption spectrometry (AAS) after dry ashing. Intake calculations were performed and it was concluded that rice may contribute considerably to the daily requirements of the essential elements Cu, Fe, Mn, Se, and Zn if rice consumption is high. The levels of some elements, e.g. Fe and Mn, were significantly higher in brown compared with white rice.  相似文献   

17.
In this study, response surface methodology was applied to determine the optimal conditions for the extraction of tea polyphenols, EGCG and theanine from summer green tea. As results, the optimal extraction conditions were determined to be temperature 96 °C, time 40 min and ratio of water to raw material 16 mL g?1. Under these optimal conditions, the experimental values for tea polyphenols, EGCG, theanine and IC50 for DPPH free radical scavenging activity were 133.41 ± 3.12 mg gallic acid g?1, 30.23 ± 1.22, 3.99 ± 1.13 mg g?1 and 724.95 ± 15.12 μg mL?1, respectively. There was no statistical difference at significant level of 0.05 between the experimental and predicted values. The results suggested that the regression models were accurate and adequate for the bioactives extraction from summer green tea.  相似文献   

18.
Results are presented for the determination of levels of Ca, Cd, Ni, Cr, Cu, Pb, Mn, Zn Fe, Co and Mg in candies and chocolates consumed in southern Nigeria. Mean concentrations of metals in both confectionaries ranged 7.7–1405.2?µg/g1 for Ca, <0.001–0.2?µg/g for Cd, 1.4–7.9?µg/g for Ni, 0.4–3.0?µg/g for Cr, <0.08–2.3?µg/g for Pb, 0.4–12.6?µg/g for Mn, 0.6–8.0?µg/g for Zn, 1.7–12.3?µg/g for Fe, <0.05–1.49?µg/g for Co, and 8.4–576.1µg/g for Mg. The data showed that that these metals are not present at harmful levels. Concentrations of nickel and chromium were slightly elevated but were comparable to levels reported in similar food items elsewhere in the world.  相似文献   

19.
In this study, two methods were developed for the sequential determination of As and Sb, Bi and Pb using fast sequential continuous flow hydride generation atomic absorption spectrometry. Limits of detection obtained for As and Sb were 0.15 and 0.16 μg?L?1 and for Bi and Pb were 0.60 and 0.77 μg?L?1, respectively. Arsenic, Sb, and Bi were free from the influence of possible interferents in the levels investigated, but Pb showed a significant analytical signal decrease when Co, Cu, Fe, Ni, and HNO3 were presented in the solutions. The methods were applied to the analysis of water from the Tietê River (São Paulo State, Brazil), sea water from Praia Grande—Ubatuba (São Paulo State), chicken feed, trace elements in water (NIST 1643e), and trace metals in drinking water (HPS TMDW). The obtained recoveries varied from 88 (for As) to 116 % (for Bi).  相似文献   

20.
In the present study, hybrid amine-functionalized titania/silica nanoparticles were employed as a new and novel adsorbent for solid-phase extraction of Pb2+, Cu2+, and Zn2+ ions prior to their determination using flame atomic absorption spectrometry. Under the best conditions (including adsorbent, 0.4 g; eluent, 5.0 mL nitric acid (HNO3), 3.0 mol L?1, 1.0 mL min?1; and sample, pH 5.0, 3.0 mL min?1), detection limits, adsorption capacities, and preconcentration factors were 0.12–0.24 μg L?1, 7.1–20.7 mg g?1, and 200, respectively. To predict the adsorption isotherms, different isotherm models were studied and the obtained results showed that the Langmuir model is the most suitable one to explain the experimental data. The kinetics of the reaction followed pseudo-second-order kinetic model. Thermodynamic parameters like free energy (ΔG 0) and enthalpy (ΔH 0) confirmed the spontaneous and exothermic nature of the process. The method was successfully applied for determination of the analytes in different food and water samples.  相似文献   

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