Element differences and evaluation of the dietary intake from farmed oysters and mussels collected at different sites along the Croatian coast of the Adriatic Sea

Concentrations of the macroelements Ca, Mg, K and Na, microelements Cr, Cu, Fe, Mn and Zn and toxic metals As, Cd, Hg and Pb were determined in oysters and mussels collected at farming sites in the northern, central and south Adriatic Sea. Mean concentrations in oysters were (mg kg⁻¹): As 4.51, Ca 1551, Cd 1.44, Cu 53.6, Cr 0.23, Fe 45.9, Hg 0.047, K 2476, Mg 895, Mn 2.80, Na 7148, Pb 0.52, Zn 675. Mean values in mussels were (mg kg⁻¹): As 4.71, Ca 601, Cd 0.37, Cu 1.91, Cr 0.29, Fe 49.6, Hg 0.026, K 2246, Mg 1043, Mn 2.49, Na 7992, Pb 0.58, Zn 28.8. Significant differences in the concentrations of toxic metals and elements were found in oysters and mussels among farming sites. Obtained Cd, Hg and Pb concentration in oysters and mussels were lower than the limit levels set by the European Community. However, Cd concentration exceeded the limit level of 1 mg kg⁻¹ in oysters from all locations except Lim Bay. The estimated daily intakes (EDIs) indicate that oysters are a good source of Ca, Cu and Zn. The higher Cu and Zn concentrations than the toxicity reference values suggest a risk for consumers if larger quantities of oysters are consumed frequently.     

Investigation of heavy metal concentrations in some Turkish wines

Research studies analysing heavy metal or trace elements in Turkish wines is scarce. This study was designed to fill this gap, analysing 43 wines produced in 4 different regions in Turkey. A total of 37 red and 6 white wines produced from various grapes from 2006 to 2008 in Marmara, Aegean, Central Anatolia and Eastern Anatolia regions were studied. Wines were analyzed for Cr, Mn, Fe, Co, Ni, Cu, Zn, Cd and Pb using atomic absorption spectrometer equipped (AAS) with electrothermal atomization unit (ET). Average results for red and white wines, respectively, were: Cr, 38.6 and 29.4 μg/L; Mn, 697 and 101 μg/L; Fe, 1.7 and 0.7 mg/L; Co, 6.3 and 0.5 μg/L; Ni, 134 and 573 μg/L; Cu, 131 and 158 μg/L; Zn, 389 and 2099 μg/L; Cd, 2.8 (red wine; white wine results were under limit of detection); Pb, 6.3 (red wine; white wine results were under limit of detection). These results were interpreted for grape types and regions. Accuracy was tested with standard addition method. Recoveries ranged from 96% to 107% after standard addition. Cr, Fe and Mn in red wines were higher in comparison to white wines, whereas white wines were higher in Ni and Zn. Non-essential Cd and Pb concentrations were very low in both red and white wines. Comparison with literature shows all heavy metal concentrations in the analyzed Turkish wines to be below the limits designated by World Health Organization.     

Major and trace elements levels in multifloral and unifloral honeys in Croatia

Different honey types were collected in Croatia during 2010 and 2011: 7 multifloral orchard honeys, 7 multifloral meadow honeys, 19 black locust, 9 chestnut, 11 lime and 6 sage honeys. Elements were measured using graphite (As, Cu, Cd, Pb, Se) and flame atomic absorption spectrometer (Ca, Fe, K, Mg, Na, Zn) and by mercury analyser (Hg). Significant differences in Ca, Fe, K, Mg, Zn, As and Hg levels were observed between honey types. In chestnut honey were determined (K, Ca, Mg: mg kg⁻¹; Hg, Ad, Cd: μg kg⁻¹): the highest concentrations of K 2824.4, Ca 486.7, Mg 59.1 and Hg 2.52; the lowest of As 24.1 and Cd 2.52. Lime honey has been shown the highest content of Cu (20.6 mg kg⁻¹), Zn (6.78 mg kg⁻¹), Cd (2.14 μg kg⁻¹) and Pb (810.3 μg kg⁻¹). The lowest levels of following elements were determined in black locust honey (Fe, K, Mg: mg kg⁻¹; Hg: μg kg⁻¹): Fe 2.77, K 304.7, Mg 8.02 and Hg 0.82. Sage honey had the lowest Ca and Na content (173.9 and 31.8 mg kg⁻¹). Among the multifloral honeys, the following was determined (Fe, Na, Cu: mg kg⁻¹; As, Pb: μg kg⁻¹): orchard honey – highest of Fe 5.17 and As 276.1, lowest Pb 301; meadow honey – highest Na 36.1, lowest Cu 4.38. The average Ca, Cu and Pb levels found in multifloral honey types were much higher than those reported in other European countries. Calcium levels in lime, chestnut and black locust were higher than those from other countries.     

Heat-assisted slurry sampling GFAAS method for determination of lead in food standard reference materials

A valid method based on heat-assisted slurry sampling graphic furnace atomic absorption spectrometry (HASS-GFAAS) was developed for the accurate determination of trace Pb in food standard reference materials (SRMs). The HASS technique significantly improved Pb recovery and precision compared to conventional slurry sampling techniques. The optimized HASS procedure was performed as follows: first, the sample (particle size ≤ 150 μm) was diluted with 0.05% (v/v) Triton X-100 containing 2% HNO₃ and 1% H₂O₂ followed by heating for 20 min at 120 °C on a heating block. Next, the obtained slurry was sonicated in an autosampler cup, and finally, the slurry was introduced into a graphite tube and analyzed by the GFAAS with a Pb electrodeless discharge lamp (EDL). Calibration with aqueous standard solutions was used for Pb determination in food samples. The characteristic mass and limit of detection for Pb based on the integrated absorbance for a 2% (m/v) sample were 12 ± 0.6 pg and 0.003 mg kg⁻¹, respectively. The accuracy (95.1–102% recovery) and good precision (0.1–3.6%) of this procedure are illustrated by the results obtained for the 12 food reference materials. The proposed method is suitable for determination of trace Pb in solid food samples.     

Essential and non-essential elements in Brazilian infant food and other rice-based products frequently consumed by children and celiac population

Rice and its derivatives are important source of essential and non-essential elements. Essential elements as cobalt (Co) and selenium (Se) are vital for human homeostasis. However, non-essential elements such as arsenic (As), cadmium (Cd) and lead (Pb) may be present in rice-based food and consequently, people can be exposed—especially children and the celiac population. This study aimed to determine essentials and non-essentials elements in rice-based products and baby food and also to evaluate nutritional risk by estimating the daily intake of non-essential elements. Regarding essential elements, Co and Se presented the highest concentrations in rice flour (56 μg kg⁻¹) and porridge (254 μg kg⁻¹), respectively. For non-essential elements, the highest concentrations of As, Cd and Pb were 104 μg kg⁻¹ (porridge), 16 μg kg⁻¹ (flour), and 188 μg kg⁻¹ (bread), respectively. Total As concentration in Brazilian rice-based baby food was <29 μg kg⁻¹. However, As-speciation revealed inorganic-As (i-As) as the main specie. The highest estimated daily intake of Cd, Pb and i-As were 1.37 (rice-based baby food); 10.39 (pasta); and 3.34 (pasta) μg d⁻¹, respectively. Therefore, continuous food monitoring for nutritional and toxicological purpose is necessary, especially concerning these particular populations and discussions for maximum levels of non-essential elements.     

Study of nutrients and toxic minerals in rice and legumes by instrumental neutron activation analysis and graphite furnace atomic absorption spectrophotometry

Instrumental neutron activation analysis (INAA) is one of the high metrological techniques for mineral determination. Nevertheless, it has some limitations for minerals with low detection limits, such as lead and cadmium, for which graphite furnace atomic absorption spectrophotometry (GF-AAS) provides reliable outcomes. This study was conducted to determine nutrients and toxic elements in four varieties of rice and six varieties of legumes. Rice and legume samples were collected from Talad-Thai and Yoawarat markets, which were representatives of rural and Bangkok areas, respectively. INAA was used for determination of various minerals whereas GF-AAS was used to determine Cd and Pb. In-house reference materials (RMs: white jasmine rice and soybeans) were prepared and their mineral contents were assigned, along with certified reference materials, by INAA and GF-AAS with standard addition technique. The INAA and GF-AAS methods were validated by various certified reference materials which showed a fairly good accuracy, 0.7–4.5% bias for INAA; 1.54 and 6.06% bias for AAS. The precision of INAA and GF-AAS, relative standard deviation (RSD) of all studied minerals was good (RSD less than 8.9%). All varieties of rice and legume seeds contain high amounts of Ca, K and Mg, whereas trace amounts of Al, Br, Cl, Fe, Mn, Zn. Cr, Cu, I, Mo, Se and Sn were found. Trace amounts of As (0.029–0.181 mg/kg) and Cd (0.010–0.025 mg/kg) were detected in all varieties of rice, but not detected in legume seeds, except that slightly higher level of Cd were found in soybeans and peanut (0.022 and 0.085 mg/kg, respectively). Low levels of Hg, ranging from 0.196 to 0.352 mg/kg, were detected in all studied sample, whereas level of Pb less than LOD (1 mcg/100 g) was found. To improve the quality of analytical mineral data, these in-house reference materials can be used as a reference material for internal and external quality control systems.     

Geographical discrimination of Italian honey by multi-element analysis with a chemometric approach

In this study the concentrations of K, Ca, Mg, Na, Al, Zn, Fe, Mn, Cu, Cr, Ni, Se, Pb, Cd, and As in 39 honey samples of different botanical (orange-blossom, lemon-blossom, chestnut, eucalyptus, acacia, sulla and wildflower honeys) and geographical (Sicily and Calabria, Italy) origin were determined by ICP-OES and ICP-MS. The most abundant minerals decreased in the following order: K (mean value: 1.57 mg g⁻¹) > Ca (0.2 mg g⁻¹) > Mg (0.121 mg g⁻¹) > Na (0.092 mg g⁻¹). Recommended Dietary Allowance (RDA) values and benchmark levels were employed to assess the honey quality and safety. The data excluded toxicological risks: for an adult of 60 kg, a daily intake of 2 g of honey covered maximum 0.40% of Tolerable Weekly Intake (TWI) for Al, 0.33% of Benchmark Dose of 1% Extra Risk (BMDL01) for Pb, and 0.07% of Tolerable Daily Intake (TDI) for Ni. Mineral content marks the differences in honey samples from different geographical origin despite the botanical factor weight and can be used as a tool to assess the traceability of honeys. The discrimination between Sicilian and Calabrian honeys was achieved by Principal Component Analysis (PCA), and also the results of Canonical Discriminant Analysis (CDA) indicate that the 100% of total samples are correctly classified. This research contributes to the studies to determine the geographical origin of honeys.     

Metal accumulation and toxicity measured by PAM—Chlorophyll fluorescence in seven species of marine macroalgae

The effects of five metals, copper (Cu), chromium (Cr), Zinc (Zn), cadmium (Cd) and lead (Pb), on photosynthetic activity, measured as pulse amplitude modulation (PAM) chlorophyll fluorescence yield, was monitored in seven species of green, red and brown macroalgae over a 14 d period. The 10 μmol l^?1 of Cr and Zn reduced chlorophyll fluorescence of all species by day 4, and 10 μmol l^?1 of Cu and Cd reduced the fluorescence of some species; however, fluorescence yields of all species were unaffected by 10 μmol l^?1 of Pb. Metals were generally accumulated in the order of Cu>Pb>Zn>Cr>Cd. Ulva intestinalis accumulated the highest amounts of all metals, and Cladophora rupestris the lowest. A relationship between internal metal concentration and fluorescence was not always evident as in some cases fluorescence was reduced at low metal contents. In the case of Zn, fluorescence was lowest in plants which contained lowest concentrations after 14 d-exposure, possibly because plants had died and Zn leached out of the algal cells. The relationship between internal metal concentration and fluorescence was algal species and metal-specific.     

Levels and daily intake of lead (Pb) and six essential elements in gari samples from Ondo State,Southwest Nigeria: A potential risk factor of health status

Gari, a staple food in most West African countries is a processed product of cassava plant. It supplies about 70% of the daily calorie intake in these countries. In this study, levels of lead (Pb), zinc (Zn), manganese (Mn), cobalt (Co), copper (Cu), calcium (Ca) and iron (Fe) in gari samples that were collected from four major Nigerian cities: Akure, Ondo, Isua and Ore – all located in Ondo State, Southwest, Nigeria were determined. The estimated daily intakes (EDI) of these elements were determined and compared to the recommended dietary intake limits or requirements. The mean concentrations of Pb in gari samples was 0.16 ± 0.09 mg/kg while for essential elements the concentrations were 4.13 ± 0.95, 0.00497 ± 0.00078, 12.98 ± 1.48, 1.01 ± 0.47, 512.6 ± 9.12 and 23.22 ± 2.32 mg/kg for Zn, Mn, Co, Cu, Ca and Fe, respectively. The mean estimated dietary intakes were 0.0333 ± 0.00443, 0.88 ± 0.21, 1.06 ± 0.36, 0.00278 ± 0.00068, 0.22 ± 0.04, 109.7 ± 4.22 and 4.97 ± 1.07 mg/day for Pb, Zn, Mn, Co, Cu, Ca and Fe respectively. The estimated mean Pb dietary intake from gari consumption alone was almost the same as the benchmark dose lower confidence limit (BMDL) for Pb, thus inferring that dietary route is a potential source of Pb contamination for gari consumers in Southwest Nigerian. Also, the data from this study indicated that gari is a good source of some essential elements like Mn, Co, and Cu but not exceptionally rich in Zn, Fe and Ca. It is therefore recommended that gari diets should be complemented with other food substances like beef, vegetables and low fat cheese that are good sources of the deficient elements.     

Comparison of the chemical composition of British and Continental European bottled waters by multivariate analysis

The elemental composition of 37 bottled waters from the UK and continental Europe has been determined. Ca, K, Mg, Na, Al, As, Ba, Cd, Cr, Co, Cu, Fe, Mn, Mo, Ni, Pb, Sb, Sr, U, V and Zn were determined by ICP-OES and ICP-MS, in addition to inorganic and total organic carbon. The composition of all the waters analysed fell within the guideline values recommended by the World Health Organization. Na, Ca, Sr and Ba showed the widest variation in concentrations, ranging over two orders of magnitude. Levels of Fe were below the limit of detection (30 μg L⁻¹) in all samples analysed. Waters produced in the UK generally showed lower levels of most major elements and trace metals, with the exception of Ba (up to 455 μg L⁻¹). Italian waters showed the highest concentrations of Sr (3000–8000 μg L⁻¹) and U (8–13 μg L⁻¹), whereas waters produced in Slovakia and the Czech Republic showed the highest levels of Pb (0.7–4 μg L⁻¹). The use of multivariate analysis reveals an association between high alkaline metal content and high concentrations of As and Cr. There also appears to be a correlation between high Ca and Sr content and high levels of U. Analysis of variance (ANOVA) indicates that the composition of bottled water can be distinguished primarily by the country of origin, over other factors including the geological environment of the source. This would suggest that composition reflects, and is biased towards, consumer preferences.     

A magnetic ion-imprinted polymer for lead(II) determination: A study on the adsorption of lead(II) by beverages

In this work a variety of beverage samples had been kept in a contaminated area to investigate their lead adsorption. To determine the adsorbed Pb(II), a novel magnetic lead ion-imprinted polymer, grafted onto Fe₃O₄ nanoparticles, was synthesized and used as a selective sorbent for the preconcentration of Pb(II) ions. The sorbent was characterized by different techniques. The synthesized sorbent was applied for highly accurate and selective determination of Pb(II) ions absorbed from polluted air in several beverages and results were compared. To validate the method, three certified reference materials were analyzed by the proposed method and the results showed that pre-concentrating by this sorbent and subsequent determination by flame atomic absorption spectroscopy is an accurate method for lead determination in beverage samples (recoveries higher than 95%). The limits of detection and the relative standard deviations were less than 1.7 μg kg⁻¹ and 4.1%, respectively. The sorption capacity of this new sorbent was 51.8 mg g⁻¹. Finally, this method was used for the determination of Pb(II) ions in polluted beverage samples, and the results revealed that under equal conditions, coffee exhibits more tendency to adsorb Pb(II) ions.     

Recognition of organic rice samples based on trace elements and support vector machines

A simple approach is proposed for the authentication of organic rice samples. The strategy combines levels of concentration of trace elements and a data mining technique known as support vector machine (SVM). Nineteen elements (As, B, Ba, Ca, Cd, Ce, Cr, Co, Cu, Fe, La, Mg, Mn, Mo, P, Pb, Rb, Se and Zn) were determined in organic (n = 17) and conventional (n = 33) rice samples by quadrupole inductively coupled plasma mass spectrometry (q-ICP-MS) and the variations found in their elemental composition resulted in profiles with useful information for classification purposes. With the proposed methodology, it was possible to predict the authenticity of organic rice samples with an accuracy of 98% when using the 19 original elements. An accuracy of 96% was found using only the elements Ca and Cd.     

Major and trace elements in sclerotium of Pleurotus tuber-regium (Ósū) mushroom—Dietary intake and risk in southeastern Nigeria

This paper presents the results of the determination of Ag, Al, Ba, Ca, Cd, Co, Cr, Cu, Fe, Hg, K, Mg, Mn, Na, Ni, P, Pb, Rb, Sr and Zn in 30 specimens of the sclerotia of Pleurotus tuber-regium mushroom from two markets in southeastern Nigeria. The elements were determined by inductively coupled plasma atomic emission spectroscopy (ICP-AES). The K and Mg contents ranged from 500 to 10,000 μg/g (dry weight), followed by Ca and Na ranging from 19 to 1700 μg/g. The median concentrations of Fe, Zn, Al, and Mn were generally >10 μg/g, followed by Rb, Cu, Sr, Ba, and P with median between 1.1 and 11 μg/g, while Cr, Ni, Ag, Co, and Cd were <1 μg/g. The Hg concentrations were between 0.0033 and 0.15 μg/g. The Pb (0.05–2.2 μg/g) and Cd (0.0027–0.16 μg/g) contents were below EU limits for these metals in fungi, and thus safe for human consumption. Principal component analysis (PCA) showed that the concentrations of Ba, Ca, Mg, P, Rb and Sr in sclerotia did not vary considerably, depending on the sampling location, as did Cd, Cu, and Mn. PCA also revealed that the Hg and Pb in sclerotia could be related to anthropogenic sources.     

Synthesis and characterization of functionalized silica with 3,6-ditia-1,8-octanediol for the preconcentration and determination of lead in milk employing multicommuted flow system coupled to FAAS

Novel functionalized silica, containing 3,6-dithia-1,8-octanediol (Si-DIO), was synthesized and characterized by infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), scanning electron microscope (SEM) and nuclear magnetic resonance (NMR) of ¹³C and ²⁹Si. The Si-DIO was used to pre-concentrate and determine the amount of Pb(II) in milk samples employing a multicommuted flow system coupled to flame atomic absorption spectrometry (FAAS). For the adsorption process, a pre-concentration minicolumn with 100 mg of Si-DIO, a solution of 0.005 mg L⁻¹ Pb(II) at pH 9.0 and HNO₃ as the eluent was used, obtaining an enrichment factor of 28 times with retention efficiency higher than 99%. The Pb(II) ion, using the multicommuted flow system coupled to FAAS, showed a linear response between 0.005 and 20.0 mg L⁻¹; a linear coefficient where r = 0.9939 and n = 7; a detection limit estimated at 0.001 mg L⁻¹ and a relative standard deviation of 3.8% (n = 50). Fifty pre-concentrations runs were tested in the minicolumn without significant variation in the analytical signal. The proposal system showed analytical applicability to determine Pb(II) ion in milk samples, presenting recovery of 90.7–102.5%.     

Determination of metal content in wild edible mushroom species from regions of Greece

Eight different species of wild edible mushrooms (Cantharellus cibarius, Hydnum repandum, Lactarius salmonicolor, Xerocomus chrysenteron, Agaricus cupreobrunneus, Amanita franchetii, Hygrophorus eburneus and Hygrophorus chrysodon) representing seven different families (Cantharellaceae, Hydnaceae, Boletaceae, Russulaceae, Agaricaceae, Amanitaceae, Hygrophoraceae) growing in Epirus (Ioannina) and West Macedonia (Grevena, Kastoria), regions of Greece were analyzed by atomic absorption spectrometry (AAS) for their metal (Mg, Cr, Mn, Fe, Co, Ni, Cu, Zn, Pb, Cd, Al, As and Sn) content. All metal concentrations were determined on a dry weight basis (d.w.). The metal content of mushroom samples ranged from 739–1165 μg/g d.w. for Mg, 0.41 to 13.1 μg/g d.w. for Cr, 11.4 to 100 μg/g d.w. for Mn, 46.3 to 317 μg/g d.w. for Fe, not detected–3.34 μg/g d.w. for Co, 0.28 to 10.1 μg/g d.w. for Ni, 3.80 to 32.6 μg/g d.w. for Cu, 35.9 to 96.9 μg/g d.w. for Zn, not detected–1.37 μg/g d.w. for Pb and 0.08 to 0.41 μg/g d.w. for Cd. As, Sn and Al concentrations were under the detection limit of the method used. This research proves that wild edible fungi which consumed traditionally in Epirus (Ioannina) and West Macedonia (Grevena, Kastoria), Greece can be used in well-balanced diets due to their high contents of functional minerals. Also, their low contents of heavy metals (Pb, Cd and As) shows that collection areas are not polluted, therefore all collected edible mushroom species can be unreservedly consumed without any health risk.     

Leaching of cadmium and lead from dried fruits and fruit teas to infusions and decoctions

Leaching of Cd and Pb from selected dried fruits (bilberries and apples) and commercially available fruit teas into infusions and decoctions during preparation of beverages, has been investigated. The content of Cd and Pb in the studied materials and water extracts was analyzed by graphite furnace atomic absorption spectroscopy. Direct slurry sampling of the examined materials to the graphite furnace gave comparable results with dry ashing mineralisation. The content of Cd and Pb in the studied materials was established and the percentage of the total content extracted to infusions and decoctions was found. The highest content of these elements was found in samples of bilberries: Cd—0.813; Pb—1.370 μg/g. The maximum obtained values for leaching of cadmium from apples, bilberries (boiling for 20 min) and fruit teas (infusion for 10 min) were 7.9%, 5.8% and 8.6%, respectively. Lead is more easily leached from the studied materials than cadmium-maximum values: 47.8% for apples; 35.3% for bilberries and 35.2% for fruit teas have been found. The evaluation of the intake of those elements with the consumption of fruits and extracts on the basis of values of provisional tolerable weekly intake (PTWI) and admissible content of the elements in the studied materials is discussed.     

Cadmium levels in food containing crab brown meat: A brief survey from UK retailers

As the brown meat of crabs accumulates cadmium (Cd) to elevated concentrations, the European Commission has recommended consumer advice on the consumption of such seafood products. To supplement available data, 397 samples (including whole crabs and products containing brown crab meat) were collected from UK retailers. Cd concentrations ranged from 0.01 to 26 mg kg −1 wet weight (ww) and mean and median concentrations of 3.4 and 2.8 mg kg⁻¹ were found, respectively. Although there is no regulatory limit for Cd in brown crab meat, mean concentrations were above the permitted maximum of 0.5 mg kg⁻¹ that applies to the white meat component derived from claws and legs. These data will support the UK Food Standards Agency’s risk assessment and management measures regarding the consumption of brown crab meat by UK consumers.     

Selenium,zinc and copper in the Polish diet

The aim of the study was to assess daily dietary intakes of selenium (Se), zinc (Zn) and copper (Cu) in a representative group of Polish individuals using analytical and calculation method, and to determine the contents of Zn and Cu in different foodstuffs available on the Polish market, in order to complete our previous data on Se content in Polish food. Daily intakes of the microelements were assessed analytically in 469 daily food rations, 439 of which were collected from various public canteens and 30 by duplicate portion method from private individuals. Calculated daily intakes were obtained by analysing 157 diet recalls and by the use of our previous and current data on Se, Zn and Cu contents in food, including 235 different food products. Mean intakes in different groups, as shown analytically, ranged from 20 to 59 μg/day for Se, 3.2 to 13.5 mg/day for Zn and from 0.4 to 2.2 mg/day for Cu. Mean daily intakes calculated from 24-h diet recalls were lower than the majority of the mean values obtained analytically and amounted to 30 ± 11 μg for Se, 5.3 ± 1.8 mg for Zn and 0.8 ± 0.3 mg for Cu. Mean concentrations of Zn and Cu in food varied from 0.4 to 17.4 μg/g and from 0.3 to 7.2 μg/g, respectively.     

Distributions of metals in the food web of fishponds of Kolleru Lake,India

The distributions of trace metals (Pb, Cd, Cr Mn, Zn and Cu) in water, sediment, plankton and four fish species (Labeo rohita, Catla catla, Pangasius pangasius and Cirrhinus mrigala) from fishponds of Kolleru Lake, India were determined using atomic absorption spectroscopy. The concentrations of lead (0.01–0.03 mg/l) and copper (0.01–0.08 mg/l) in water and cadmium (3.0–9.0 mg/kg), chromium (47–211 mg/kg) and copper (10–64 mg/kg) in sediment were above the EPA threshold effects level (TEL) and are of biological concern. The abundance orders of metals were Mn>Cd>Cu>Pb in water, Mn>Cr>Zn>Cu >Pb>Cd in sediment and Cu>Mn>Cr>Zn>Pb>Cd in plankton. The concentrations of the metals in the muscles of these four fish species apparently decrease in the order Zn>Cu>Cr>Mn=Pb>Cd and were well below WHO permissible limits that were safe for human consumption.     

A rapid and sensitive method for the determination of dibutyl phthalate in wine by flow-injection chemiluminescence analysis

A sensitive method for the determination of picogram level dibutyl phthalate (DBP) in wine by flow-injection chemiluminescence (FI–CL) analysis is presented for the first time, which was based on the quenching effect of DBP on the luminol–myoglobin (Mb) CL system. The decrement of CL intensity was linearly proportional to the logarithm of DBP concentration in the range of 0.1–100 pg mL⁻¹ with the detection limit of 0.03 pg mL⁻¹ (3σ). At a flow rate of 2.0 mL min⁻¹, a complete determination of DBP including sampling and washing could be accomplished in 0.5 min, giving the maximum sample throughput of 120 h⁻¹. The proposed method was successfully applied to the determination of DBP in wine, human serum and urine samples with the relative standard deviations (RSDs) of less than 3.0% (n = 5). The molecule docking results showed that DBP interacted with the amino acid residues near the heme moiety of Mb. The possible CL mechanism of luminol–Mb–DBP reaction should be that the binding of Mb with DBP forming a 1:1 complex (binding constant K = 1.55 × 10⁴ L mol⁻¹) led to the conformational change of Mb and resulted in the quenching of CL intensity.