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1.
《Analytical letters》2012,45(5):932-941
The heavy metal content was investigated for six mushroom species native to Jordan. Metal (Cu, Pb, Cd, Fe, Zn, Mn, Ni, and Co) content in soil substrate and their relation to metal concentrations in mushroom and underlying soil were determined by flame and graphite furnace atomic absorption spectrometry. Mushroom species and soil were collected from different places in Jordan. The highest Cu level was 51.84 µg g?1 for the species Lepista nuda; whereas, the lowest Cu level was found to be 18.51 µg g?1 in Calvatia utriformis. Among the wild mushrooms, the highest Pb level was found as 4.81 µg g?1 in Bovista plumbea, whereas the lowest Pb concentration was 2.01 µg g?1 in Calvatia utriformis. The highest Cd level was determined as 1.9 µg g?1 for Lepista nuda, whereas the lowest Cd level was 0.58 µg g?1 for the species of Polyporus frondosus. The highest Zn level was 58.77 µg g?1 for the species of Lepista nuda and the lowest Zn concentration was found 35.98 µg g?1 in Calvatia utriformis. The highest Fe level was found as 317 µg g?1 in Lepista nuda, whereas the lowest Fe concentration was 211.7 µg g?1 in Calvatia utriformis. The highest Mn content was 36.55 µg g?1 for Russula delica, whereas the lowest Mn level was 24.5 µg g?1 for the species Bovista plumbea. The highest Ni content was found as 12.65 µg g?1 for Russula delica, whereas the lowest Ni level was 0.17 µg g?1 for Bovista plumbea. The highest Co content in the tested mushrooms was found as 3.5 µg g?1 for the species of Agaricus bisporus, whereas the lowest Co level was 0.85 µg g?1 for Polyporus frondosus. The results indicated that, in general, heavy metal contents in all mushroom species were lower than the underlying soil substrates except for some mushroom species.  相似文献   

2.
《Analytical letters》2012,45(11):1952-1964
The distributions of cadmium and lead in marine sediments, surrounding soil, stones, and atmospheric particulate matter were determined at different locations in Split, Croatia. The determination of cadmium and lead was performed by flame atomic absorption spectrometry whereas atmospheric particulate matter samples were analyzed by inductively coupled plasma–optical emission spectrometry. Cadmium concentrations in the stones and soil were between 0.2 to 0.6 µg g?1 and 0.2 to 0.9 µg g?1. The concentration in the atmospheric particulate matter were <0.2 µg m?2 d?1(detection limit) to 1.4 µg m?2 d?1. Lead concentrations in marine sediments, stones, soil, and atmospheric particulate matter ranged from 31.2 to 144.4 µg g?1, 9.3 to 29.4 µg g?1, 11.3 to 66.1 µg g?1, and 0.5 to 241.4 µg m?2 d?1, respectively. The relationship between determined parameters was established using principal component analysis and the results are in agreement with the assumption that anthropogenic sources play important roles for lead and cadmium distribution.  相似文献   

3.
《Analytical letters》2012,45(10):1842-1852
A dynamic ultrasound-assisted extraction method using Atomic Absorption and Atomic Fluorescence spectrometers as detectors was developed to analyze mercury, arsenic, and barium from herbarium mount paper originating from the herbarium collection of the National Museum of Wales. The variables influencing extraction were optimized by a multivariate approach. The optimal conditions were found to be 1% HNO3 extractant solution used at a flow rate of 1 mL min?1. The duty cycle and amplitude of the ultrasonic probe was found to be 50% in both cases with an ultrasound power of 400 W. The optimal distance between the probe and the top face of the extraction chamber was found to be 0 cm. Under these conditions the time required for complete extraction of the three analytes was 25 min. Cold vapor and hydride generation coupled to atomic fluorescence spectrometry was utilized to determine mercury and arsenic, respectively. The chemical and instrumental conditions were optimized to provide detection limits of 0.01 ng g?1 and 1.25 ng g?1 for mercury and arsenic, respectively. Barium was determined by graphite-furnace atomic absorption spectrometry, with a detection limit of 25 ng g?1. By using 0.5 g of sample, the concentrations of the target analytes varied for the different types of paper and ranged between 0.4–2.55 µg g?1 for Ba, 0.035–10.47 µg g?1 for As, and 0.0046–2.37 µg g?1 for Hg.  相似文献   

4.
The possibility of using ionic liquid based chitosan sorbent for the separation and preconcentration of fluoroquinolone antibiotics (marbofloxacin, enoxacin, ofloxacin, ciprofloxacin, and enrofloxacin) has been studied. For this reason, different ionic liquids were prepared and coated on the chitosan sorbent. The conditions of the preconcentration of fluoroquinolones on a microcolumn have been optimized and the extraction efficiencies of the prepared sorbents have been compared. The compounds were eluted with 5 mL of 20% NH3 (v/v, MeOH) solution and determined by HPLC with diode array and fluorescence detector. The limits of detection were found as 4.23 µ g L?1 for marbofloxacin, and 1.09 µg L?1 for enoxacin; 3.23 × 10?3 µg L?1 for ofloxacin; 8.39 × 10?3 µg L?1 for ciprofloxacin; and 19.50 × 10?3 µg L?1 for enrofloxacin. The developed method was applied for the analysis of fluoroquinolone in milk, egg, fish, bovine, and chicken samples and the recoveries were obtained in the range 70–100%.  相似文献   

5.
《Analytical letters》2012,45(6):1052-1062
A new simplified extraction of gold(III) using a room-temperature ionic liquid prior to determination by flame atomic absorption spectrometry has been developed. The extraction method uses 1-butyl-3-methylimidazolium hexafluorophosphate without a chelating agent. The parameters of the extraction system were investigated in detail. Under the optimized conditions, a linear range of 0.19 to 38.20 µg · mL?1, a limit of detection of 0.072 µg · mL?1, an enrichment factor of 10.0, and an extraction capacity of 6.6 mg · g?1 were obtained. The extraction mechanism and the selectivity of 1-butyl-3-methylimidazolium hexafluorophosphate for gold(III) were also investigated. The method was applied for the determination of gold(III) in water samples with satisfactory results.  相似文献   

6.
A simple, rapid and efficient method termed dispersive liquid–liquid microextraction combined with liquid chromatography-fluorescence detection, has been developed for the extraction and determination of polycyclic aromatic hydrocarbons (PAHs) in water and fruit juice samples. Parameters such as the kind and volume of extraction solvent and dispersive solvent, extraction time and salt effect were optimized. Under optimum conditions, the enrichment factors ranged from 296 to 462. The linear range was 0.01–100 μg L?1 and limits of detection were 0.001–0.01 μg L?1. The relative standard deviations (RSDs, for 5 μg L?1 of PAHs) varied from 1.0 to 11.5% (n = 3). The relative recoveries of PAHs from tap, river, well and sea water samples at spiking level of 5 μg L?1 were 82.6–117.1, 74.9–113.9, 77.0–122.4 and 86.1–119.3%, respectively. The relative recoveries of PAHs from grape and apple juice samples at spiking levels of 2.5 and 5 μg L?1 were 80.8–114.7 and 88.9–123.0%, respectively. It is concluded that the proposed method can be successfully applied for determination of PAHs in water and fruit juice samples.  相似文献   

7.
《Analytical letters》2012,45(8):1400-1408
There are three major production bases of navel oranges in China, including Southern Jiangxi Province, Southern Hunan Province, and the Three Gorges District of the Yangtze River. Southern Jiangxi and Southern Hunan are also famous for rare earth elements that are ionic, making them easily passed from soil to plants and fruits. To test the relative enrichment of rare earth elements in navel oranges from these production sites, ICP-MS analysis was performed following a microwave digestion procedure. The concentrations of La, Ce, Pr, and Nd in navel orange peels from Southern Jiangxi and Southern Hunan (1.26–1.86 µg g?1) were much higher than results from the Three Gorges (0.23–0.46 µg g?1). Moreover, yttrium is relatively enriched (0.25–0.29 µg g?1) in navel orange peels from Southern Jiangxi at concentrations almost twice that from Southern Hunan (0.15 µg g?1). The various concentrations and distribution of rare earth elements offers the possibility of traceability and authentication of navel oranges. Meanwhile, navel orange peels from Southern Jiangxi posed no risk in consumption, based on the maximum limit level (≤0.7 µg g?1, wet weight) of rare earth elements in food issued in China (GB 2762-2005).  相似文献   

8.
A sensitive method has been developed for the trace analysis of PAHs and their oxidation products (i.e., nitro-, oxy-, and hydroxy-PAHs) in air particulate matter (PM). Following PM extraction, PAHs, nitro-, oxy-, and hydroxy-PAHs were fractionated using solid phase extraction (SPE) based on their polarities. Gas chromatography–mass spectrometry (GC–MS) conditions were optimized, addressing injection (i.e., splitless time), negative-ion chemical ionization (NICI) parameters, i.e., source temperature and methane flow rate, and MS scanning conditions. Each class of PAH oxidation products was then analyzed using the sample preparation and appropriate ionization conditions (e.g., nitro-PAHs exhibited the greatest sensitivity when analyzed with NICI–MS while hydroxy-PAHs required chemical derivatization prior to GC–MS analysis). The analyses were performed in selected-ion-total-ion (SITI) mode, combining the increased sensitivity of selected-ion monitoring (SIM) with the identification advantages of total-ion current (TIC). The instrumental LODs determined were 6–34 pg for PAHs, 5–36 pg for oxy-PAHs, and 1–21 pg for derivatized hydroxy-PAHs using electron ionization (GC-EI-MS). NICI–MS was found to be a useful tool for confirming the tentative identification of oxy-PAHs. For nitro-PAHs, LODs were 1–10 pg using negative-ion chemical ionization (GC-NICI-MS). The developed method was successfully applied to two types of real-world PM samples, diesel exhaust standard reference material (SRM 2975) and wood smoke PM.  相似文献   

9.
《Analytical letters》2012,45(1-3):12-24
A simple and sensitive flow-injection method is reported for the determination of retinol and α-tocopherol in human blood serum and pharmaceuticals. The method is based on the reduction of vanadium(V) by retinol and α-tocopherol and subsequent reaction of reduced vanadium with luminol to generate chemiluminescence signal. The optimized conditions allow a linear calibration range of 30–2850 µg L?1 and 5–4300 µg L?1 for retinol and α-tocopherol, with relative standard deviations of 1.2–4.6% and 1.5–5.6%, respectively. The detection limits for retinol and α-tocopherol, defined as three times the standard deviation of measured blanks were 23 µg L?1 and 2.15 µg L?1, respectively. The proposed method allowed up to 20 determinations h?1. The tolerance amount of foreign ions/compounds on the determination of retinol and α-tocopherol was also examined. The method was applied to the determination of retinol and α-tocopherol in human blood serum and pharmaceutical samples using hexane extraction with recoveries in the range of 92 ± 2 to 96 ± 1%, and the results obtained were compared with HPLC reference method.  相似文献   

10.
《Analytical letters》2012,45(10):1758-1768
This paper reports the determination of the mineral composition of watercress (Nasturtium officinale Cruciferae, Brassicaceae), grown in soils from three cities in the Bahia State of Brazil, and in a fourth city where plants were grown in a hydroponic system. The sampling was carried out during the summer and winter. Analyses were performed with inductively coupled plasma optical emission spectrometry (ICP OES), and the accuracy was confirmed with a certified reference material of apple leaves.

Principal component analysis (PCA) and hierarchical cluster analysis (HCA) revealed different mineral compositions of the samples collected in the summer and winter.

Samples collected in the summer had a higher concentration of the nutrients iron, calcium, and magnesium, and the samples collected in the winter had a higher concentration of manganese and copper. The average contents of the samples (expressed as wet weight) were 2.50 and 3.03 mg g?1 for calcium, 0.37 and 0.86 mg g?1 for magnesium, 8.68 and 10.84 µg g?1 for iron, 8.42 and 8.47 µg g?1 for zinc, 0.61 and 0.47 µg g?1 for copper, and 7.78 and 5.03 µg g?1 for manganese for summer and winter, respectively. These results are in agreement with values previously reported in the literature. Samples collected from the hydroponic system in the winter had a lower concentration of all nutrients.  相似文献   

11.
Ghiasvand  Ali Reza  Heidari  Nahid 《Chromatographia》2016,79(17):1187-1195

To reinforce the extraction efficiency of the liquid- and solid-phase microextraction methods, different cooling-assisted setups have been employed, most of which are complicated, expensive, tedious, and do not show good performances due to indirect transfer of cold to the extraction phase. In this research, a simple, low-cost and effective cooling-assisted headspace hollow fiber-based liquid-phase microextraction (CA-HS-HF-LPME) device was fabricated and evaluated, which is able to directly cool down the extraction phase in different modes of LPME. It was coupled to GC-FID and utilized for the direct determination of PAHs in contaminated soil samples using volatile organic solvents. Different effective experimental variables including type and volume of extraction solvent, extraction time and temperature, and temperature of the cooled organic solvent were evaluated and optimized. Under the optimized experimental conditions (e.g., organic extracting solvent: 3 µL of acetone; extraction time: 20 min; extraction temperature: 90 °C; and temperature of cooled organic drop: −25 °C), good linearity of calibration curves (R 2 > 0.99) was obtained in a concentration range of 1–10,000 ng g−1. The limits of detection (LODs) were obtained over the range of 0.01–0.1 ng g−1. The relative standard deviations (RSD%, n = 6) of 0.1 µg g−1 PAHs were found to be 4.7–10.1 %. The CA-HS-HF-LPME-GC-FID method was successfully used for the direct determination of PAHs in contaminated soil and plant samples, with no sample manipulation. The results were in agreement with those obtained by a validated ultrasound-assisted solvent extraction (UA-SE) method.

  相似文献   

12.
《Analytical letters》2012,45(1):48-59
Parthenium hysterophorus L., is an obnoxious weed known for its environmental health hazards and medicinal uses. These characteristics are due to presence of sesquiterpene lactones and organic acids; therefore a rapid and sensitive analytical procedure using HPLC-PDA-MS-MS was developed and optimized for separation, identification, and quantification of parthenin and six organic acids. Separation and characterization of compounds was achieved on a RP-C18 column with 1% acetic acid in water (A) and acetonitrile (B) as a mobile phase at a flow rate of 0.6 mL min?1 and by matching their UV and mass spectra with reference compounds. Six organic acids (ferulic acid, 0.1 mg g?1 to coumaric acid, 13.6 mg g?1) and parthenin (27.4 mg g?1) were characterized within 26 minutes of chromatographic separation in plant extract. The calibration curves are linear with correlation coefficients from 0.985 to 0.998, limit of detection and quantification ranged between 1.0 µg mL?1 (anisic acid) to 2.2 µg mL?1 (parthenin) and 2.5 µg mL?1 (coumaric acid) to 5.2 µ g mL?1 (parthenin) and recovery ranged between 90.9% to 97.3%. To the best of our knowledge this is the first report for the simultaneous separation of parthenin and organic acids. The method is applicable for screening of commercial crops, medicinal plants, and their products which might be mixed with P. hysterophorus during harvesting period.  相似文献   

13.
《Analytical letters》2012,45(17):2792-2807
Ultrasensitive Square Wave Anodic Stripping Voltammetry is used for the first time for the systematic determination of Cd, Pb, and Cu in siliceous spicules of marine sponges; the procedure is performed directly in hydrofluoric acid solution, according to a procedure previously established in our laboratory, with the aim of demonstrating the feasibility of such measurements and to improve knowledge of heavy metal distribution in Porifera. The following Demospongiae species are considered: Sphaerotylus antarcticus, Haliclona sp., Kirkpatrickia coulmani, and Inflatella belli from the Ross Sea, Antarctica, and Petrosia ficiformis from the Mediterranean Sea, Italy. The method shows a good accuracy; the analytical variability is approximately ±10% for all the metals studied and for all the measurements performed, showing a good repeatability of the method in consideration of low metal concentrations (order of tenths of µg g?1 dry weight, i.e., of hundreds of ng L?1 in the HF solution). In particular, the concentrations of heavy metals in the body of the sponge vary in the range 0.038–0.93 µg g?1 dry weight (d.w.) for Cd, 0.024–0.52 µg g?1 d.w. for Pb, and 0.32–1.3 µg g?1 d.w. for Cu. Similar ranges of concentration were recorded in the oscula of S. antarcticus and I. belli. Heavy metal concentration in the spicules can vary within and between specimens and, in particular, siliceous spicules of Antarctic sponges show higher concentrations of Cd and Pb and lower concentrations of Cu than those from the Mediterranean.  相似文献   

14.
《Analytical letters》2012,45(8):1324-1333
This study describes the validation of an analytical method employing gas chromatography with flame photometric detection for the determination of organophosphate pesticides (diazinon, disulfoton, parathion, chlorpyrifos, and malathion) in strawberries. The method employed a QuEChERS dispersive solid phase extraction for the sample preparation. QuEchERS is inexpensive, fast, and easy for the separation of the analytes from the matrix. In addition, the method provided linear calibration curves, ranging from 0.10–1.00 µg g?1, for diazinon, disulfoton, parathion, and chlorpyrifos, and 0.10–2.00 µg g?1 for malathion. Recovery studies yielded values in the range from 81.64 to 100.00%. These results demonstrated the potential of the technique for the determination of organophosphate residues in strawberries.  相似文献   

15.
《Analytical letters》2012,45(17):2747-2757
Abstract

Brazilian sugarcane spirits were analyzed to elucidate similarities and dissimilarities by principal component analysis. Nine aldehydes, six alcohols, and six metal cations were identified and quantified. Isobutanol (LD 202.9 µg L?1), butiraldehyde (0.08–0.5 µg L?1), ethanol (39–47% v/v), and copper (371–6068 µg L?1) showed marked similarities, but the concentration levels of n-butanol (1.6–7.3 µg L?1), sec-butanol (LD 89 µg L?1), formaldehyde (0.1–0.74 µg L?1), valeraldehyde (0.04–0.31 µg L?1), iron (8.6–139.1 µg L?1), and magnesium (LD 1149 µg L?1) exhibited differences from samples.  相似文献   

16.
In this work, magnetic solid-phase extraction based on sodium dodecyl sulfate-coated Fe3O4 nanoparticles has been successfully applied for extraction and preconcentration of trace amounts of nystatin from water and vaccine samples prior to high-performance liquid chromatography–ultraviolet detection. Various experimental parameters affecting extraction and recovery of the analyte, such as the amount of sodium dodecyl sulfate, pH of the sample solution, salt concentration, extraction time, sample volume and desorption conditions, were systematically studied and optimized. Under optimized conditions, nystatin was quantitatively extracted. Proper linear range with good coefficient of determination, (R 2 > 0.99) and limit of detection and quantification (based on signal-to-noise ratios of 3 and 10) of 2.0 and 5.0 µg L?1, over the investigated concentration range (5–700 µg L?1), were obtained, respectively. The intra-day and inter-day relative standard deviations at 50 µg L?1 level of NYS were 1.4 and 4.5% based on six replicate determinations. The accuracy of the method was evaluated by recovery measurements on spiked samples. Suitable recoveries of 96–102 and 26–44% were achieved (at spiked levels of 50, 300 and 500 µg L?1) for water and vaccine samples, respectively.  相似文献   

17.
《Analytical letters》2012,45(2):343-355
A new analytical procedure for the determination of five organotin compounds in several matrix wine samples is reported. The organotin compounds were extracted by microwave-assisted extraction with n-hexane. Extraction conditions, such as volume of n-hexane required, extraction temperature, and extraction time, were investigated and optimized by an orthogonal array experimental design. The determination of organotin compounds in the final extracts was carried out by liquid chromatography–inductively coupled plasma mass spectrometry. The procedure showed limits of detection between 0.029–0.049 µg · L?1. The linearity was in the range of 0.5 to 100 µg · L?1. The precision expressed as relative standard deviation (RSD) was below 9.43%. The developed method was successfully employed to analyze different matrix wine samples, and some analytes were detected at the level of 0.053 to 1.14 µg · L?1.  相似文献   

18.
《Analytical letters》2012,45(6):1085-1097
Abstract

A methodology for the determination of the pesticide chlorfenvinphos by microwave‐assisted solvent extraction and square‐wave cathodic stripping voltammetry at a mercury film ultramicroelectrode in soil samples is proposed. Optimization of microwave solvent extraction performed with two soils, selected for having significantly different properties, indicated that the optimum solvent for extracting chlorfenvinphos is hexane‐acetone (1∶1, v/v). The voltammetric procedure is based on controlled adsorptive accumulation of the insecticide at the potential of?0.60 V (vs. Ag/AgCl) in the presence of Britton‐Robinson buffer (pH 6.2). The detection limit obtained for a 10 s collection time was 3.0×10?8 mol l?1. The validity of the developed methodology was assessed by recovery experiments at the 0.100 µg g?1 level. The average recoveries and standard deviations for the global procedure reached by MASE‐square‐wave voltammetry were 90.2±2.8% and 92.1±3.4% for type I (soil rich in organic matter) and type II (sandy soil) samples, respectively. These results are in accordance to the expected values which show that the method has a good accuracy.  相似文献   

19.
《Analytical letters》2012,45(13):2075-2088
For the first time, a simple method for magnetic stirring-assisted dispersive suspended microextraction has been developed for the determination of three fungicides (azoxystrobin, diethofencarb, and pyrimethanil) in water and wine samples. The method is based on the solidification of a floating organic droplet coupled with high performance liquid chromatography. In the proposed method, the low toxicity solvent 1-dodecanol was used as the extractant. Both the extraction and phase separation process were performed with magnetic stirring. No centrifugation step was involved. After separating the two phases, the extraction solvent droplet was easily collected through solidification at lower temperature. Important parameters such as the kind and volume of organic extraction solvent, extraction and restoration speed, extraction and restoration time, and salt concentration were optimized. Under the optimal conditions, the limits of detection for the analytes varied from 0.14 to 0.26 µg L?1. The enrichment factors ranged from 125–200. The linearity ranges were 1–2000 µg L?1, yielding correlation coefficients (r) higher than 0.9990. The relative standard deviation (n = 6) at two spiked level of 0.2 µg mL?1 and 4 µg L?1 varied between 2.2% and 7.8%. Finally, the developed technique was successfully applied to determine target fungicides in real water and wine samples, where the obtained recoveries ranged from 83.8–105.3%  相似文献   

20.
Inorganic elements are responsible for essential bodily functions, such as osmotic regulation, cardiac frequency and contractibility, blood clotting and neuromuscular excitability. The determination of inorganic elements in corporeal fluids such as blood, serum, plasma and urine is used as a monitor for a part or the whole organism; their values, then, are compared with reference interval values. In this study, the energy dispersive X-ray fluorescence spectrometry (EDXRF), applying the Fundamental Parameters method, for the determination of inorganic elements in whole blood samples from humans and laboratory animals, was used. Peripheral blood samples were collected and, before coagulation, 100 μL of sample were deposited onto Whatman No. 41 filter paper and dried, using infrared spotlight. The reference interval values for healthy Brazilian population of Na were found to be 1,788–1,826 μg g?1, of Mg 63–75 μg g?1, of P 602–676 μg g?1, of S 1,519–1,718 μg g?1, of Cl 2,743–2,867 μg g?1, of K 1,508–1,630 μg g?1, of Ca 214–228 μg g?1, of Fe 170184 μg g?1, of Cu 4–6 μg g?1 and of Zn 1–3 μg g?1. The reference interval values for golden hamster (Mesocricetus auratus) of Na were found to be 1,714–1,819 μg g?1, Mg 51–79 μg g?1, P 970–1,080 μg g?1, S 1,231–1,739 μg g?1, Cl 2,775–2,865 μg g?1, of K 1,968–2,248 μg g?1, of Ca 209–257 μg g?1, of Fe 145–267 μg g?1, of Cu 4–6 μg g?1 and of Zn 3–5 μg g?1. A comparative study between EDXRF and instrumental neutron activation analysis data was carried out and the results for both techniques are statistically equal (α = 0.05). The results contribute for the establishment of reference interval values for Na, Mg, P, S, Cl, K, Ca, Cu and Zn in the healthy Brazilian population and the referred laboratory animal species.  相似文献   

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