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1.
This study describe an analytical method employing gas chromatography (GC) using flame photometric detection that has been developed for the simultaneous determination of organophosphate pesticides (diazinon, disulfoton, parathion, chlorpyrifos and malathion) in strawberry samples. For this purpose, molecularly imprinted solid-phase extraction was applied as a sample preparation technique. The method was linear in the ranges from 0.10 to 1.00?μg?g?1, for diazinon, disulfoton, parathion and chlorpyrifos, and 0.10 to 2.00?μg?g?1 for malathion with r?>?0.99. The detection limits (LD) ranged from 0.02 to 0.05?μg?g?1. Recovery studies yielded average recoveries in the range of 65.25 to 87.70?%. These results showed the potential of this technique for organophosphate residue monitoring in strawberry samples.  相似文献   

2.
分散液液微萃取-气相色谱法快速测定水中23种有机磷农药   总被引:2,自引:0,他引:2  
建立了分散液液微萃取(DLLME)的新型样品前处理方法,并采用气相色谱/火焰光度检测器对饮用水中的治螟磷、甲拌磷、二嗪农、乙拌磷、甲基毒死蜱、甲基对硫磷、皮蝇磷、杀螟松、马拉硫磷、毒死蜱、倍硫磷、对硫磷、溴硫磷、嘧啶磷、甲基异硫磷、稻丰散、杀扑磷、丙溴磷、乙硫磷、三唑磷、三硫磷、哒嗪硫磷、亚胺硫磷23种痕量有机磷农药残...  相似文献   

3.
《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   

4.
Palladium nanoparticles supported on MWCNTs (Pd/MWCNTs) were successfully prepared by a simple ethylene glycol reduction method in an oil bath. An electrochemical sensor based on Pd/MWCNTs nanocomposite-modified glassy carbon electrode was fabricated for the determination of methyl parathion by differential pulse voltammetry measurement. A highly linear response to methyl parathion in the concentration ranging from 0.10 μg mL?1 to 14 μg mL?1 was observed, and a detection limit of 0.05 μg mL?1 was obtained with the calculation based on signal/noise?=?3. The present work provides a simple and rapid approach to the detection of methyl parathion.  相似文献   

5.
Summary A rapid and efficient multiresidue extraction procedure using ethyl acetate and sodium sulfate has been applied to the analysis of diazinon, methamidophos, chlorpyrifos, malathion, parathion, parathion-methyl, dimethoate and monocrotophos residues in many different kinds of vegetables. No cleanup step was required Concentrated extracts were analysed by gas chromatography with flame photometric detection in phosphorus mode. Recovery studies were performed in six kinds of matrices at two fortification levels. Recoveries were in the range 80–115%. The limit of quantification of the analytical method has been estimated as 0.01 ppm for diazinon, methamidophos and malathion, 0.03 ppm for chlorpyrifos, parathion, parathion-methyl and dimethoate and 0.1 ppm for monocrotophos. Experiments showed that potentially it should be possible to develop a rapid and universally applicable method for organophosphate pesticide residues in different matrices.  相似文献   

6.
In the present study the main factors that may influence the headspace single-drop microextraction (HS-SDME) of common pesticide contaminants (diazinon, lindane, chlorpyrifos ethyl, p,p′-DDE, and endosulfan) that may occur in honey were determined and an analytical protocol was further developed by the use of a multivariate optimization. The HS-SDME analytical method developed and two more analytical protocols for the determination of pesticides in honey: (i) by direct SDME (D-SDME), and (ii) by liquid–liquid extraction (LLE), were further validated for the determination of target analytes. The three methods were also applied in the same real honey samples and results were further discussed. By D-SDME, LODs ranged from 0.04?µg?kg?1 for β-endosulfan to 2.40?µg?kg?1 for diazinon and repeatability expressed as %RSD from 3 for lindane to 15 for diazinon and chlorpyrifos methyl; by HS-SDME, LODs ranged from 0.07?µg?kg?1 for p,p′-DDE to 12.54?µg?kg?1 for chlorpyrifos methyl and repeatability expressed as %RSD from 11 for chlorpyrifos methyl to 19 for p,p′-DDE; by LLE, LODs ranged from 0.09?µg?kg?1 for β-endosulfan to 19.31?µg?kg?1 for diazinon and repeatability expressed as %RSD from 6 for p,p′-DDE to 11 for lindane. For all target pesticides but p,p′-DDE that could not be recovered by D-SDME method tested. The proposed HS-SDME optimized in this study was shown to be the method of choice for the determination of diazinon in honey whereas the most favourable analytical characteristics from the comparative study performed were achieved by D-SDME.  相似文献   

7.
《Analytical letters》2012,45(12):1999-2013
Abstract

A simple, rapid, selective, and sensitive method for the derivative spectrophotometric determination of Hg(II) and its simultaneous determination in the presence of Zn(II) using 2‐(5‐bromo‐2‐pyridylazo)‐5‐diethylaminophenol in the presence of cetylpyridinium chloride, a cationic surfactant, has been developed. The molar absorption coefficient and analytical sensitivity of the 1∶1 Hg(II) complex at 558 nm (λmax) are 5.78×104 L mol?1 cm?1 and 0.67 ng mL?1, respectively. The detection limit of Hg(II) is 1.40×10?2 ng mL?1, and Beer's law is valid in the concentration range 0.05–2.40 µg mL?1. Overlapping spectral profiles of Hg(II) and Zn(II) complexes in zero‐order mode interfere in their simultaneous determination. However, 0.10–2.00 µg mL?1 of Hg(II) and 0.065–0.650 µg mL?1 of Zn(II), when present together, can be simultaneously determined at zero cross point of the derivative spectrum, without any prior separation. The relative standard deviation for six replicate measurements of solutions containing 0.134 µg mL?1 of Hg(II) and 0.620 µg mL?1 of Zn(II) is 1.72 and 1.47%, respectively. The proposed method has successfully been evaluated for trace level simultaneous determination of Hg(II) and Zn(II) in environmental samples.  相似文献   

8.
《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   

9.
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   

10.
《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   

11.
《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   

12.
Commercial solid-phase extraction (SPE) cartridges with C18 bonded silica packings effectively cleaned up acetonitrile extracts of 3-g samples of fats and oils for determination of organophosphorus pesticide residues by gas chromatography with flame photometric detection. Cartridges from three different sources were tested and found to differ in lipid capacity and inertness (free silanol activity). Consequently, the amount of packing (i.e., number of cartridges) and/or the choice of eluent used were adjusted for each brand of cartridge to achieve optimum clean-up and analyte recovery. Seven pesticides with a wide range of polarity (acephate, azodrin, chlorpyrifos, diazinon, malathion, methamidophos and methyl parathion) were separated from coextracted lipids by elution with either acetonitrile or methanol, depending on the brand of cartridge used. Cartridges were regenerated by purging lipids with dichloromethane and were reused numerous times without apparent loss of effectiveness. Recoveries from vegetable oils and butterfat fortified with the seven compounds at levels of 0.05–0.87 μg g?1 ranged from 80 to 103%. Practical limits of determination range from 0.01 to 0.08 μg g?1, depending on analyte response.  相似文献   

13.
With the wide range of metallic contaminants discharged in the environment, studying the human health requires a growing number of elements to be monitored in biological samples. Hair analysis has been suggested as a suitable tool for biomonitoring environmental and occupational exposure to toxic elements. This study describes a method for the determination of 10 trace elements in hair samples using ICP-QQQ-MS. Combining the power of the MS/MS high-energy Helium mode with the MS/MS O2 mass-shift mode, the method offers great analytical performances with detection limits reaching 0.0014 µg g?1 for As, 0.0016 µg g?1 for Cd, 0.012 µg g?1 for Cr, 0.0035 µg g?1 for Hg, 0.0055 µg g?1 for Mn, 0.10 µg g?1 for Ni, 0.0012 µg g?1 for Sb, 0.0083 µg g?1 for Sn, 0.011 µg g?1 for Se and Pb. The accuracy of the method was tested on a human hair ERM® certified reference material. Percent recoveries varied from 91.3% and 106.9% being always in the acceptance range of 90–110%. For all analysed elements, RSD% of repeatability ranged between 0.6% and 9.0% and those of intermediate precision did not exceed the limit of 20% being always lower than 10% (except for As). The proposed method was applied for the determination of trace elements in hair samples from 20 unexposed subjects. The geometric mean levels were as follows: Cr 0.28 µg g?1, Mn 0.30 µg g?1, Sn 1.04µg g?1, Sb 0.07 µg g?1, Hg 0.42 µg g?1, As 0.02 µg g?1, Cd 0.03 µg g?1, Ni 0.51 µg g?1, Se 0.45 µg g?1 and Pb 1.83 µg g?1. Element concentrations were in the same range with the reported data. The reported results may be useful for environmental exposure assessment or comparisons studies when establishing reference values of trace elements in exposed population.  相似文献   

14.
An effective method utilising pressurised fluid extraction (PFE) to simultaneously extract polycyclic aromatic hydrocarbons (PAHs) and their polar oxidation products from atmospheric particulate matter (PM) is presented. The PFE method is advantageous over the traditional Soxhlet extraction due to its lower solvent consumption (9 mL compared to 90 mL) and shorter extraction time (15 min versus 18 h). Seventy compounds including PAHs and polar PAH oxidation products containing carbonyl (oxy-PAHs), hydroxyl (hydroxy-PAHs), and carboxylic acid (carboxy-PAHs) groups were targeted in the extraction of two different PM matrices: wood smoke (WS) and diesel exhaust (DE) PM. The PFE method was optimised and then compared to Soxhlet extraction for both PM matrices. The overall amounts of PAHs and their derivatives extracted from WS PM were slightly higher for the optimised PFE method (1849 ± 21 and 1863 ± 25 µg g?1 with dichloromethane (DCM) and methanol (MeOH), respectively) than those obtained with Soxhlet extraction (1726 ± 33 and 1769 ± 22 µg g?1 with DCM and MeOH, respectively). For DE PM (standard reference material (SRM) 2975) the overall amounts extracted by both methods were similar (average of 165 ± 6 µg g?1), agreeing with previously published values. The detailed evaluation of extraction efficiencies for WS PM showed similar amounts for unfunctionalised PAHs (1100 µg g?1) for both methods and solvents. For DE PM the mass yields for PAHs using PFE with DCM (62 ± 1 µg g?1) were the highest and nearly 20% higher than those obtained with MeOH (53 ± 2 µg g?1). The total mass yields of carboxy and hydroxy-PAHs from WS PM were also similar (412 ± 18 and 407 ± 11 µg g?1) for PFE and Soxhlet with MeOH, and higher than when DCM was used (371 ± 5 and 379 ± 12 µg g?1 for PFE and Soxhlet, respectively). For both matrices, the PFE yields for oxy-PAHs were higher than those obtained with Soxhlet.  相似文献   

15.
《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   

16.
《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   

17.
Beeswax is a complex mixture of lipophilic compounds and other components such as aliphatic alcohols and carotenoids. Then, extraction and clean-up for pesticide analysis in beeswax is a challenge. In this work, a multiresidue method for the analysis of dichlorvos (DCV), diazinon, malathion, methyl parathion and coumaphos (CMF) in beeswax was developed. The proposed approach is based on matrix solid-phase dispersion extraction. The adsorbent for sample clean-up was studied and a simplex-centroid cubic statistical design was applied to evaluate pure solvents and their binary and ternary mixtures to elute the analytes. Finally, Florisil and ethyl acetate were chosen as solid support and eluting solvent, respectively. After extraction, pesticides were separated and detected by gas chromatography/mass spectrometry. The method achieved acceptable recoveries (70–85%; except for DCV, 24–38%) with relative standard deviations below 5%. The repeatability of the method was lower than 8% and interday variability was below 12%. The limit of detection (LOD) for the analytes varies between 0.2 and 2.6 µg?kg?1 and limit of quantification from 0.93 to 8.8 µg?kg?1. LOD reached for CMF was below the maximum residue limit allowed by the legislation of the United States and Canada.  相似文献   

18.
《Analytical letters》2012,45(14):2214-2231
Abstract

A new simple and sensitive method has been proposed for rapid determination of trace levels of silver in environmental water samples, using dispersive liquid–liquid microextraction (DLLME) prior to its microsample introduction-flame atomic absorption spectrometry. Under the optimum conditions, the linear range was 0.1–7 µg L?1 and limit of detection was 0.018 µg L?1. The relative standard deviation for 0.50 and 5.00 µg L?1 of silver in water sample was 4.0 and 1.7%, respectively. The relative recoveries of silver from tap, well, river, and seawater samples at spiking levels of 1.00 and 5.00 µg L?1 were in the range of 86.4–98.6%.  相似文献   

19.
《Analytical letters》2012,45(8):1375-1386
Abstract

A novel chemiluminescence method for the quantitative assay of the organophosphorus pesticide chlorpyrifos in vegetable samples is presented. The determination is based on the reaction of chlorpyrifos with luminol-H2O2 in alkaline medium with sodium chloride being enhancer. Under the optimum conditions, the increased CL intensity was proportional with the concentration of chlorpyrifos in the range of 1.0 × 10?8 g · ml?1 ? 1.0 × 10?6 g · ml?1 and the detection limit was 3.5 × 10?9 g · ml?1 (3σ). The relative standard is less than 3.9% for 5.0 × 10?7g · ml?1 chlorpyrifos (n = 7). This method has been successfully applied to the determination of chlorpyrifos residue in vegetable sample. Further study was focused on the mechanism of chlorpyrifos and the possible mechanism was proposed.  相似文献   

20.
An SPE-HPTLC method for simultaneous identification and quantification of seven pharmaceuticals in production wastewater was optimized and validated. The studied compounds were enrofloxacine, oxytetracycline, trimethoprim, sulfamethazine, sulfadiazine, sulfaguanidine and penicillin G/procaine. The method involves solid-phase extraction on hydrophilic-lipophilic balance cartridges with methanol and HPTLC analysis of extracts on CN modified chromatographic plates followed by videodensitometry at 254 and 366 nm. Optimization of chromatographic separation was performed by systematic variation of the mobile phase composition using genetic algorithm approach and the optimum mobile phase composition for TLC separation was 0.05 M H2C2O4:methanol = 0.81:0.19 (v/v). Linearity of the method was demonstrated in the ranges from 1.5 to 15.0 μg L−1 for enrofloxacine, 100–500 μg L−1 for oxytetracycline, 150–600 μg L−1 for trimethoprim, 300–1100 μg L−1 for sulfaguanidine and 100–400 μg L−1 for sulfamethazine, sulfadiazine and penicillin G/procaine with coefficients of determination higher than 0.991. Mean recoveries ranged from 74.6 to 117.1% and 55.1 to 108.0% for wellspring water and production wastewater, respectively. Only sulfaguanidine showed lower results. The described method has been applied to the determination of pharmaceuticals in wastewater samples from pharmaceutical industry.  相似文献   

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