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《Saudi Journal of Biological Sciences》2017,24(3):589-594
A cloud point extraction (CPE) method was used as a pre-concentration strategy prior to the determination of trace levels of silver in water by flame atomic absorption spectrometry (FAAS) The pre-concentration is based on the clouding phenomena of non-ionic surfactant, triton X-114, with Ag (I)/diethyldithiocarbamate (DDTC) complexes in which the latter is soluble in a micellar phase composed by the former. When the temperature increases above its cloud point, the Ag (I)/DDTC complexes are extracted into the surfactant-rich phase. The factors affecting the extraction efficiency including pH of the aqueous solution, concentration of the DDTC, amount of the surfactant, incubation temperature and time were investigated and optimized. Under the optimal experimental conditions, no interference was observed for the determination of 100 ng·mL−1 Ag+ in the presence of various cations below their maximum concentrations allowed in this method, for instance, 50 μg·mL−1 for both Zn2+ and Cu2+, 80 μg·mL−1 for Pb2+, 1000 μg·mL−1 for Mn2+, and 100 μg·mL−1 for both Cd2+ and Ni2+. The calibration curve was linear in the range of 1–500 ng·mL−1 with a limit of detection (LOD) at 0.3 ng·mL−1. The developed method was successfully applied for the determination of trace levels of silver in water samples such as river water and tap water. 相似文献
3.
María Victorina Aguilar Carmen Jos Mateos María Carmen Martínez Para 《Journal of trace elements in medicine and biology》2002,16(4):221-225
A rapid method to determine the chromium content of cerebrospinal fluid (CSF) samples using electrothermal atomization atomic absorption spectrometry (ETA-AAS) with deuterium-arc background correction is described. The chromium concentration in CSF was evaluated by the standard addition method. Sample dilution (1 + 1) with 0.25% (m/v) Triton X-100 and 4.5% (v/v) HNO3 gave the best combination of sensitivity, reproducibility, and low blank reading compared with dilution using other solvents. Within-batch reproducibility was 3.2% for 20 CSF samples, between-batch reproducibility was 4.7%. CSF samples from 43 healthy volunteers collected in a manner designed to avoid contamination yielded chromium concentrations of 14.6 ± 6.3 ng mL−1. 相似文献
4.
A procedure using open digestion followed by flame atomic absorption spectrometry is described for measuring the total selenium
content of Se-enriched yeast. The limits of detection and quantitation were 2.5 mg/L and 5 mg/L Se, respectively. The signal
response was linear over the range of 5–50 mg/L Se, and the average recovery from spiked samples was 98.9%. The validated
method was used to measure the Se content of Se-enriched yeast reference material and produced a result of 2145±38 mg/kg (n=3), which is in good agreement with the certified level of 2125 ±65 mg/kg. 相似文献
5.
Marina M. A. Campos Henry Tonuci Silvana M. Silva Bruna de S. Altoé Dermeval de Carvalho Eloisa A. M. Kronka Ana M. S. Pereira Bianca W. Bertoni Suzelei de C. França Carlos E. S. Miranda 《Phytochemical analysis : PCA》2009,20(6):445-449
Introduction – Although medicinal plants are widely used throughout the world, few studies have been carried out concerning the levels of heavy metal contaminants present. Such metals are highly toxic to living organisms even in low concentrations owing to their cumulative effect. The present paper describes the the development of a pre‐concentration flow injection analysis‐flame atomic absorption spectrometric system to determine the lead content in medicinal plants at the ppb level. Objective – To develop a pre‐concentration flow injection analysis‐flame atomic absorption spectrometric system to determine the lead content in medicinal plants at the ppb level. Methodology – A pre‐concentration flow system was coupled to a flame atomic absorption spectrometer. The plant samples were analysed after nitroperchloric digestion. The proposed system was optimised by evaluating the following parameters: nature, concentration and volume of the eluent solution, elution flow rate, elution efficiency, pre‐concentration flow rate and pre‐concentration time. Results – The proposed system exhibited good performance with high precision and repeatability (RSD ≤ 2.36%), excellent linearity (r = 0.9999), low sample consumption (10.5 mL per determination) and an analytical throughput of 55 samples/h. Lead concentrations ranged from 3.37 ± 0.25 to 7.03 ± 0.51 μg/g in dry material. This concentration interval is greater than that previously published in the literature. Conclusion – The inclusion of a pre‐concentration column in the flow manifold improved the sensitivity of the spectrometer. Thus, it was possible to determine the analyte at the ng/mL level in sample solutions of medicinal plants. This is a very important accomplishment, especially when the cumulative effect of heavy metals in living organisms is considered. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
6.
Fifteen kinds of common plants, animals, and minerals used as traditional medicines by the Chinese people have been subjected
to analysis by atomic absorption spectrometry for its content of seven metals: lead, cadmium, arsenic, mercury, copper, cobalt,
and manganese. The concentrations of these elements are significantly different according to their vegetal, animal, or mineral
origin. The average values found for lead, cadmium, arsenic, cobalt, and manganese in drugs of mineral origin are higher than
those derived from plants and animals, except for copper, which was higher in drugs of animal origin.
Our results suggest that the user of traditional Chinese crude drugs should be warned of the potential danger of heavy-metal
poisoning because their concentrations seem to be higher than the maximum values allowed by health agencies in several countries. 相似文献
7.
Trace elements in phytomedicines are present in the form of metallic complexes. Since n-octanol, a long-chain alkanol, presents a configuration similar to that of carbohydrates and lipids, the lipophilicity and absorptivity of organic medicines may be assessed from their distribution coefficients between octanol and water. This strategy has been used in order to define the species of manganese in a number of phytomedicines and to study the distribution of manganese in decoctions of phytomedicines in the stomach and the intestine. The concentrations of manganese in the original herbal materials and in octanol- and water-soluble fractions were determined by flame atomic absorption spectrometry following mixed acid digestion. The acidities of gastric and intestinal juices, the phytomedical composition and the compatibility of phytomedicines, i.e. the combination of single phytomedicines, greatly affected the manganese complexing ligands and determined the species and bioavailability of manganese. It is concluded that a knowledge of the level of octanol-soluble manganese in a phytomedicine could form the basis of dosage design in order to avoid manganese overload. 相似文献
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Massadeh AM Al-Safi SA Momani IF Al-Mahmoud M Alkofahi AS 《Biological trace element research》2007,115(2):157-167
Analysis and distribution of Pb and Cd in different mice organs, including the liver, kidney, spleen, heart, and blood, were
evaluated before and after treatment with different aqueous concentrations of Nigella sativa (1.25–10.0 mg/L). Atomic absorption spectrometry was used for analysis of Pb and Cd in these organs. Results indicated that
the Pb in the unexposed group of mice without treatment with N. sativa (black cumin) was in the following order: liver>heart>spleen>kidney, and the distribution of Pb in various organs of the
unexposed group was not affected significantly by N. sativa. Moreover, results of mice exposed for Pb show that the Pb concentrations in different organs were reduced significantly
(p<0.05) by 72.9%, 63.4%, 72.3%, 66.7%, and 39.5% at a dose of 10 mg/L of N. sativa for the liver, kidney, heart, spleen, and blood, respectively. Furthermore, the distribution of Cd in the unexposed Cd group
of mice without treatment with N. sativa was in the following order: kidney>heart>spleen>liver. Nigella sativa at 10 mg/L reduced Cd levels in mice exposed to Cd by 75.5%, 83.3%, 47.0%, 95.3%, and 100% in the liver, kidney, heart, spleen,
and blood, respectively, whereas blood Cd concentrations were lowered to below the detection limit of 0.05 μg/L.
A 28-d exposure of mice to a Cd−Pb mixture at a concentration of 1 ppm in drinking water induced a highly significant inhibition
(p<0.0001) of antibody response to human serum (80.5%). The suppressed immune responses in mice pretreated with the Cd−Pb mixture
were reversed by 43.1% and 38.9% in the presence of 1.25 and 2.5 mg/mL of N. sativa, respectively, whereas higher concentrations (5–10 mg/mL) of N. sativa increased the immunosuppression significantly. Nigella sativa at 1.25–10 mg/mL did not induce any significant modulation of the antibody response in unexposed mice. 相似文献
9.
BackgroundAn effective, green and rapid analytical strategy namely the simultaneous spray assisted droplet formation-liquid phase microextraction (S-SADF-LPME) method was developed for the determination of trace quantity of cadmium in saliva samples by using the slotted quartz tube-flame atomic absorption spectrophotometry (SQT-FAAS). By the developed method, external dispersive solvent usage for droplet formation was reduced to obtain a more environmental-friendly method.MethodsMethod consists of a simultaneous complexing and extraction step, which was based on spraying an extraction solvent containing a solid ligand into the aqueous sample solution, forming fine droplets without the use of dispersive solvent. The procedure was implemented using a customized, cost effective and portable spray apparatus to minimize the consumption of reagent, analysis time and operation steps. Thus, this methodology ensures better repeatability and accuracy while minimizing the relative errors caused by the experimental steps. Parameters including the buffer amount, extractant/ligand concentration, extraction solvent type, extraction/ligand solution volume, spraying number and vortex period were systemically optimized to lower the detection limit.ResultsUnder the optimal extraction conditions, 96.9-folds enhancement in the detection power of the traditional FAAS was achieved. The limit of detection and limit of quantification values of presented method were calculated to be 0.65 and 2.17 ng mL−1, respectively. Accuracy and applicability of the optimized method was investigated by collecting saliva samples from smokers. Satisfactory percent recovery values wereachieved for cadmium with a low standard deviation in the acceptable range of 84.9–109.6 %.ConclusionThe developed dispersive solvent-free S-SADF-LPME technique presents a fast, simple, cost-effective and eco-friendly microextraction method based on the use of an easily accessible and functional spray apparatus. 相似文献
10.
An assay for cadmium in whole blood and urine using deuterium background-correction electrothermal atomic absorption spectroscopy (D(2)-ETAAS) was developed. Cadmium (in a 1- to 2-ml sample) was bound to 15 mg anion-exchange resin, interfering ions were removed in a 2-ml Bio-Spin column, and cadmium was extracted into 100 microl 1M nitric acid for analysis. Cadmium in the sample extract was concentrated 7-fold for blood and 10-fold for urine over the starting material. These steps produced cadmium atomic absorption traces with high signal to background ratios and allowed analysis against aqueous standards. At approximately 0.1 ng Cd/ml, mean intra- and interassay coefficients of variation were 11-12%. Cadmium recovery for 0.1 to 0.6 ng added cadmium was 107+/-4% for blood and 94+/-4% for urine (mean+/-SE, n=3). The mean detection limit (mean + 3 x SD of blank) was 0.008 ng/ml for blood and 0.003 ng/ml for urine. Samples from "unexposed" animals including humans ranged from 0.051+/-0.000 to 0.229+/-0.035 ng/ml. Values were approximately 10-fold lower than those obtained by the method of Stoeppler and Brandt using Zeeman background-correction ETAAS. This new high-sensitivity, low-volume assay will be useful for epidemiological studies, even those involving children, and will provide a means to help determine the contribution of cadmium to disease incidence in the general population. 相似文献
11.
Cobalt determinations in biological fluids are of great interest in biological or toxicological research programs. Cobalturia
is often chosen as an indicator for a biological monitoring program in occupational exposure to cobalt dusts. The method described
here derives from the IUPAC reference method for nickel determination. It enables cobaltemia and cobalturia to be measured
in small samples (1 mL). The mean usual values for cobalt in biological fluids are very low (2.7 nmol L−1 for serum and 6.7 nmol L−1 for urine), and therefore, thus require an analytical procedure with preconcentration and extraction. The sample is mineralized
by wet acid digestion. After digestion, inorganic cobalt is extracted in form of ammonium pyrrolidine dithiocarbamate complex
into isobutyl methyl ketone and measured in the organic layer by electrothermal atomic absorption spectrometry.
The analytical parameters are described in detail. The extraction output is about 99%. The detection limits are 1.93 and 1.89
nmol L−1 for serum and urine, respectively. Sensitivity (expressed as the concentration that gives a 0.044 absorbance) is 3.4 nmol
L−1 for serum and 3.3 nmol L−1 for urine.
Within-run precision ranged between 3.9 and 2.5% (coefficients of variation) for serum and 4.2 and 1.1% for urine, at 87 and
136 nmol L−1 levels, respectively. Between-run precision ranged between 4.3 and 3.3% (coefficients of variation) for serum and 4.2 and
2.3% for urine, at 87 and 136 nmol L−1 levels, respectively. At very low concentration, 5.7 nmol L−1 for serum and 2.5 nmol L−1 for urine, the between-run precision is, respectively, 19.5 and 28%.
Linearity is effective between 0 and 272 nmol L−1. Interferences and matrix effects are negligible for urine, serum, or plasma samples without hemoglobin. The method is easily
applicable for routine determinations. 相似文献
12.
Distribution of cadmium and lead in a stream ecosystem 总被引:1,自引:3,他引:1
Cadmium and lead were detected in all components of the stream that were examined. Cadmium was present in similar concentrations in both fishes and sediments. Aquatic insects, however, exhibited higher concentrations of cadmium than did sediments. Lead concentrations in sediments and aquatic insects were similar, but higher than concentrations in fishes. Snails contained the highest level of lead and had noticeably greater amounts of the metal than did aquatic insects. In general, concentrations of both metals increased successively from water to fish to sediments to aquatic invertebrates. 相似文献
13.
Determination of selenium in the human brain by graphite furnace atomic absorption spectrometry 总被引:2,自引:0,他引:2
Akiko Ejima Chiho Watanabe Hiroshi Koyama Kyoko Matsuno Hiroshi Satoh 《Biological trace element research》1996,54(1):9-21
For the investigation of neurological disorders, a development of simple and accessible methods for determining selenium in
human brain samples is required. We devised a method of determining selenium using graphite furnace atomic absorption spectrometry
(GFAAS). An electrodeless discharge lamp provided the sufficient sensitivity to determine brain selenium. The matrix interferences
were avoided by using high temperature, a prolonged pyrolysis step, and a palladium matrix modifier. The technique of standard
addition was used to evaluate the sample concentrations. The accuracy of the method was confirmed by a bovine liver reference
material. The detection limit of selenium was 0.04 ng. The determined selenium concentrations of human brain cortex and white
matter were higher than those of putamen (115–155 and 206–222 ng/g wet wt, respectively). These GFAAS values agreed with those
obtained by fluorometric analysis (r=0.91,n=10). Moreover, the GFAAS values were compatible to those reported by other researchers (99–274 ng/g wet wt), in which selenium
concentrations in putamen also tended to be higher than the other two regions. We conclude that GFAAS is useful for selenium
analysis in brain samples. 相似文献
14.
Jiřina Korečková-Sysalová 《Biological trace element research》1997,56(3):321-329
The development of a method for the direct determination of cadmium (Cd) and lead (Pb) in blood samples by GFAAS, is described.
Samples were properly diluted by a matrix modifier to enable measuring both analytes in one solution. For the determination
of Cd, a matrix-matched, and for the determination of Pb, an aqueous calibration was used. The precision, accuracy, and detection
limits of this method are presented. A method is applied to the investigation of Cd and Pb levels in a general Czech population,
selected according to the WHO-MONICA project criteria. To avoid possible contaminations, samples were treated in a clean room
class 100. 相似文献
15.
Wael I. Mortada Mohammed M. Hassanien Ahmed A. El-Asmy 《Journal of trace elements in medicine and biology》2013,27(4):267-272
A highly sensitive and selective technique for the speciation of platinum by cloud point extraction prior to determination by graphite furnace atomic absorption spectrometry (GFAAS) was described. The separation of Pt(II) from Pt(IV) was performed in the presence of 4-(p-chlorophenyl)-1-(pyridin-2-yl)thiosemicarbazide (HCPTS) as chelating agent and Triton X-114 as a non-ionic surfactant. The extraction of Pt(II)–HCPTS complex needs temperature higher than the cloud point temperature of Triton X-114 and pH = 7, while Pt(IV) remains in the aqueous phase. The Pt(II) in the surfactant phase was analyzed by GFAAS, and the concentration of Pt(IV) was calculated by subtraction of Pt(II) from total platinum which was directly determined by GFAAS. The effect of pH, concentration of chelating agent, surfactant, and equilibration temperature were investigated. An enrichment factor of 42 was obtained for the preconcentration of Pt(II) with 50 mL solution. Under the optimum experimental conditions, the calibration curve was linear up to 30 μg L?1 with detection limit of 0.08 μg L?1 and the relative standard deviation was 1.8%. No considerable interference was observed due to the presence of coexisting anions and cations. The accuracy of the results was verified by analyzing different spiked samples (tap water, blood plasma and urine). The proposed method was applied to the speciation analysis of Pt in blood plasma and urine with satisfactory results. 相似文献
16.
《Chemical Speciation and Bioavailability》2013,25(2):124-128
AbstractA simple, rapid and inexpensive method of the solidified floating organic drop extraction (SFODME) technique coupled with graphite furnace atomic absorption spectrometry (GFAAS) has been developed for the determination of cobalt in water samples. 8-Hydroxyquinoline was used as a complex agent and 1-undecanol was used as the extraction solvent. The factors, including solvent types, solution pH, extractant volume and interfering ions, were investigated and optimised. Under the optimum conditions, the calibration graphs were linear in the range 0.05–10.0 ng mL-1 cobalt, the limit of detection was 0.02 ng mL-1, the limit of quantification was 0.05 ng mL-1 and the relative standard deviation for 10 replicate measurements of 3 ng mL-1 cobalt was 2.8%. The proposed method was successfully applied for the determination of cobalt in different water samples and the results were satisfactory. 相似文献
17.
Forty-nine refinery workers and 50 motor mechanics were selected and examined for total lead (PbT), inorganic lead (PbI),
and δ-aminolevulinic acid (ALA) in urine. The worker groups were exposed to tetraethyl lead (TEL) mainly by inhalation, but
motor mechanics received additional exposure by skin because of hand cleansing with gasoline.
The levels of urinary ALA (ALA-U) and urinary PbT (PbT-U) in refinery workers and motor mechanics were found to be significantly
higher than the control group (p<0.05). The correlation between the ALA-U and PbT-U was found significant in both worker groups (p<0.001); however, relatively higher positive correlation was found between ALA-U and urinary inorganic lead (PbI-U) in TEL-exposed
workers. 相似文献
18.
This article reports on the levels of cadmium, lead, and mercury in 21 benign brain tumors and 23 malignant brain tumors.
All measurements were performed by atomic absorption spectrometry following digestion by nitric acid. Average concentrations
of cadmium, lead, and mercury in brain tumors were 2.02 (ND-72.78), 0.625 (ND-83.13), and 0.118 (ND-1.96) μg/g wet weight,
respectively. Our values were higher than data reported by others. 相似文献
19.
Muñoz-Delgado E Morote-García JC Romero-Romero R López-García I Hernández-Córdoba M 《Analytical biochemistry》2006,348(1):64-68
An electrothermal atomic absorption spectrometric procedure for zinc determination in animal tissues is first optimized and then used to measure the metal content of different tissues from normal and dystrophic mice. The procedure involves minimal manipulation of the sample to overcome the severe contamination problems normally associated with the measurement of low zinc levels. The samples (recommended amount 10 mg) are slurried in 2 ml of a 10-mM tetramethylammonium hydroxide solution containing 0.1 g/100 ml silicone antifoam. After mild heating at 60 degrees C for 10 min and homogenization for 1 min, the suspensions are submitted to a 10-fold dilution and then injected into the electrothermal atomizer. Calibration is carried out using aqueous standard solutions of zinc prepared in the same suspension media. The reliability of the whole procedure is verified using three certified reference materials. 相似文献
20.
One of the major threats to patients undergoing maintenance hemodialysis is an increased susceptibility to infections caused by microorganisms, among whichYersinia orListeria are frequently recovered. In patients receiving hemodialysis, iron overload owing to multiple transfusions plays an important role in the mechanisms underlying the susceptibility to bacterial infections, partially mediated by impaired neutrophil function. In order to assess the true role of iron at the cellular level, an AAS method was developed to measure the iron content of granulocytes. Iron levels in the granulocytes were determined in an apparently healthy population and in a population of iron-overloaded renal hemodialysis patients. Granulocytes were isolated by a method modified from Böyum. The analyses were performed using pyrocoated graphite tubes, and in one of the char steps, oxygen was used to facilitate ashing. The mean iron level found in the granulocytes from apparently normal persons was 4.07 fg/cell (n=17) with a CV of 44%; the mean value for the dialysis patient group was 4.59 fg/cell (n=8) with a CV of 37%. There was no significant difference between the two groups,p=0.70. 相似文献