Trace Amounts Of Cd Research Articles

Optimizing Room-Temperature Thermoelectric Performance of n-Type Bi2Te2.7Se0.3.

Bi2Te3-based compounds are exclusive commercial thermoelectric materials around room temperature. For n-type compounds, optimal thermoelectric properties are normally obtained at temperatures higher than room temperature to suppress the bipolar effect through increased carrier concentration. We find that doping with trace amounts of Cd and the addition of excess Bi are effective ways to optimize carrier concentration and achieve enhanced room-temperature thermoelectric performance for the Bi2Te2.7Se0.3 alloy in this work. For the Cd-doped samples, the replacement of Cd with Bi leads to not only a significant decrease in electron concentration but also apparently reduces the total thermal conductivity. The addition of excess Bi in the samples creates a Bi-rich synthetic atmosphere during the synthesis process, leading to increased BiTe antisite defects, decreased electron concentration, and reduced total thermal conductivity. Doping a small amount of Cd or adding excess Bi causes optimal thermoelectric performance of the n-type Bi2Te2.7Se0.3 sample shifts obviously toward low temperatures, and the samples with 0.4 atom % Cd and 0.8 atom % excess Bi achieve maximum zT of ∼0.97 at 448 K and ∼0.88 at 348 K, respectively.

Site- and Spatial-Selective Integration of Non-noble Metal Ions into Quantum Dots for Robust Hydrogen Photogeneration

Summary Artificial photosystems consisting of semiconductor quantum dots (QDs) and non-noble metal ions (e.g., Fe2+, Co2+, Ni2+) show intrinsic advantages in efficient and cost-effective hydrogen (H2) evolution. However, well-controlled integration of these metal ions into ultra-small QDs is a major challenge. Here, we present a two-step strategy to realize site- and spatial-selective integration of earth-abundant Fe2+ ions in CdSe QDs; i.e., CdSe QDs are modified with a thin and anisotropic ZnS shell, and partial Zn2+ ions are selectively substituted by Fe2+ via cation exchange. The anisotropic ZnS layer not only passivates CdSe core but also works as an ideal medium to intimately anchor Fe2+. The multifunctional CdSe/Zn1−xFexS QD exhibits extraordinary activity and stability toward H2 photogeneration. Specifically, more than 880 mL (∼39,300 μmol) H2 gas is produced from 6 mL of aqueous solution during a consecutive 172 h (>1 week) experiment, thus achieving a turnover number of >600,000 per QD.

Co-microprecipitation/flotation of trace amounts of cadmium from environmental samples through its complexation with iodide and neutralization with cetyltrimethylammonium bromide in the presence of perchlorate ions

ABSTRACTA fast, cost-effective and reliable method is presented for separation and preconcentration of trace amounts of cadmium based on co-precipitation and flotation prior to its flame atomic absorption (AAS) spectrometric determination. Cadmium (II) was complexed with iodide and neutralized with cetyltrimethylammonium bromide (CTAB) in the presence of perchlorate ions. This resulted in the formation of a bulky precipitate containing the ternary complex of CdI4(CTA)2, floating on the top of the solution. The aqueous layer was then simply drained out, the floated layer was dissolved in 1.0 mL of acetonitrile, and its Cd content was determined by flame atomic absorption spectrometry. The parameters affecting the designed separation method such as KI, CTAB, and ClO4− concentration, pH, ionic strength, volumes of sample and dissolving solvent, and extraction time were studied and optimized. For preconcentration of 200 mL of the sample, the calibration graph was linear in the range of 1–30 μg L−1 of cadmium with a correlation coefficient of 0.9997, enhancement factor of 194 and a limit of detection of 0.18 μg L−1. The relative standard deviation for seven replicate determinations at 20 μg L−1 levels of cadmium was found to be 2.1%. The effect of the presence of different common cations and anions on the separation and determination of Cd(II) by the developed method was studied. The method was successfully applied to the determination of trace amounts of Cd(II) ions in different types of real samples including tap water, polluted industrial wastewater, dust, and soil with the recoveries in the range of 95.3 to 103.4.

Water hyacinth modified carbon paste electrode for simultaneous electrochemical stripping analysis of Cd (II) and Pb (II)

ABSTRACTIn this study, we demonstrated a highly sensitive electrochemical sensor for the simultaneous detection of Pb (II) and Cd (II) in aqueous solution using carbon paste electrode modified with Eichhornia crassipes powder by square wave anodic stripping voltammetry. The effect of modifier composition, pH, preconcentration time, reduction potential and time, and type of supporting electrolyte on the determination of metal ions were investigated. Pre-concentration on the modified surface was performed at open circuit. The modified electrode exhibited well-defined and separate stripping peaks for Pb (II) and Cd (II). Under optimum experimental conditions, a linear range for both metal ions was from 10 to 5000 μg L−1 with the detection limits of 4.9 μg L−1, 2.1 μg L−1 for Cd(II) and Pb (II), respectively. The modified electrode was found to be sensitive and selective when applied to determine trace amounts of Cd (II) and Pb (II) in natural water samples.

Development of a green effervescence-assisted dispersive liquid–liquid microextraction method using a home-made tablet disperser for trace analysis of Cd(II) and Pb(II)

ABSTRACTAn analytical approach for the determination of trace amounts of Cd(II) and Pb(II) has been developed using a home-made tablet-based effervescence-assisted dispersive liquid–liquid microextraction (DLLME) method which was performed in a narrow-bore tube, followed by flame atomic absorption spectrometry. In this method, a mixture of tartaric acid, sodium bicarbonate and NaCl was used to make the disperser tablet. Then, microlitre level of an extraction solvent was added in the tablet, and then, it was released into a narrow-bore tube containing sample solution and a complexing agent. An acid–base reaction immediately occurred between tartaric acid and sodium bicarbonate, and the produced CO2 led to the dispersion of the extraction solvent into the solution as tiny droplets and subsequent extraction of the analytes. The method made possible the determination of Cd(II) and Pb(II) in the ranges of 0.1–10 and 1.0–20 µg L−1, respectively. The limits of detection were obtained 0.43 and 0.05 µg L−1 for Pb(II) and Cd(II), respectively. The limits of quantifications were 0.80 and 0.09 µg L−1 for Pb(II) and Cd(II), respectively. Repeatability of the method, which is expressed as relative standard deviation, was obtained 3.1% (n = 6, C = 2 µg L−1) and 1.3% (n = 6, C = 0.2 µg L−1) for Pb(II) and Cd(II), respectively. The accuracy of the developed method was verified by analysing a certified reference material, namely SPS-WW2 Batch 108. Relative recoveries (84–107%, obtained at three fortification levels) confirmed the usefulness of the method for analysis of the analytes in the environmental water samples and fruit juices. The method was shown to be fast, reliable and environmentally friendly with low organic solvent consumption.

Trace amounts of Cd(II), Cu(II) and Pb(II) ions monitoring using Fe 3 O 4 @graphene oxide nanocomposite modified via 2-mercaptobenzothiazole as a novel and efficient nanosorbent

Abstract In the current research for the first time, modification of magnetic graphene oxide (GO@Fe3O4) with 2-mercaptobenzothiazole (MBT) groups was described and applied for rapid separation/preconcentration of trace heavy metal ions including cadmium(II), copper(II), and lead(II). This nanosorbent can be recovered by applying an external magnetic field which results in easy separation of the sorbent without filtration. The effects of several factors such as pH, amount of sorbent, extraction time, type and volume of the eluent, sample volume, sorption capacity, and potentially interfering ions were investigated. Under the optimum conditions, linear dynamic ranges were achieved in the range of 0.3–80 ng mL− 1 for Cd(II), 0.4–100 ng mL− 1 for Cu(II), and 1–140 ng mL− 1 for Pb(II). The limits of detection (LODs) calculated using 3(Sb) blank/m and were 0.19, 0.24 and 0.35 ng mL− 1 for Cd(II), Cu(II), and Pb(II), respectively. In conclusion, the proposed method was simple, rapid, novel, straightforward, and highly efficient procedure for trace determination of cadmium, copper, and lead ions in different matrices.

Responses of Carbonic Anhydrase to Cadmium in the Zinc/Cadmium Hyperaccumulator Picris divaricata Vant.

A number of higher plants are able to hyperaccumulate cadmium (Cd). However, it is unknown whether cadmium (Cd) plays a biological functional role in the carbonic anhydrase (CA) of hyperaccumulators. A hydroponic experiment was conducted to explore the potentially physiological function of Cd in CA and the accumulation and tolerance of Cd in the Zn/Cd hyperaccumulator Picris divaricata Vant. P. divaricata was exposed to nutrient solutions with six Cd concentrations (0, 5, 10, 25, 50 and 75 μmol L−1). After 12 d, plants were harvested for the analysis of plant biomass, Cd concentration and CA activity. The Cd concentrations in plant increased with the increasing Cd in nutrient solution, reaching 640 and 3 100 mg kg−1 in shoot and root, respectively, at the 75 μmol L−1 Cd treatment. Meanwhile, plant growth was enhanced by the Cd treatments at 5–25 L−1, but it was significantly inhibited when the plants were exposed to solutions with higher Cd concerntrations (50 and 75 μmol L−1). Exposure to Cd significantly increased the CA activity in P. divaricata, which reached a maximum value of 21.27 U mg−1 proteins at the 25 μmol L−1 Cd treatment, and the CA activity and shoot Cd concentration were positively correlated at solutions Cd of ≤ 25 μmol L−1. Moreover, two protein bands appeared on the denatured gel electrophoresis of purified CA, indicating that P. divaricata may have CA isomers with their respective molecular weights at around 60 and 55 kDa, at least one of which is Cd-bound. In addition, trace amounts of Cd in purified CA significantly increased with the supplied Cd concentration in nutrient solution (5–25 μmol L−1). The results suggested that Cd may play a biological role by enhancing the activities and forming the active Cd-specific CA in the hyperaccumulator P. divaricata.

Maternal cadmium exposure reduces placental zinc transport and induces fetal growth restriction in mice

Cadmium (Cd) is linked with increased risk of fetal growth restriction (FGR). Nevertheless, the mechanism remains unknown. This study established a mouse model of Cd-induced FGR through two exposure methods. Pregnant mice were either administered with CdCl2 (5, 50 and 250ppm) throughout pregnancy through drinking water or intraperitoneally injected with CdCl2 (4.5mg/kg) on GD9. As expected, fetal weight and crown-rump length were reduced in a gender-independent manner. Interestingly, Mt1 and Mt2, two metallothionein genes, were up-regulated in maternal liver. Correspondingly, Cd accumulated mainly in maternal liver and kidney, and only trace amounts of Cd could pass from dam to placentas and fetuses. Further analysis showed that placental Zn concentration was elevated. Conversely, embryonic Zn concentration was reduced. Moreover, placental Znt1 and Znt2, two zinc transporters, were down-regulated in Cd-exposed mice. These results suggest that maternal Cd exposure during pregnancy reduces placental Zn transport and induces fetal growth restriction.

Soil Pollution by the Cement Industry in the Bazian Vicinity, Kurdistan Region

The three most significant things in our life are air, water, and soil which are essential for life and any imbalance of these three cause a big problem in nature. Soil is one of the most common agents in life and supplies us with all the basic necessities. Portland cement is one of the common types of cement which is used in construction nowadays. But soil can be polluted by cement plants, where cement industries are established. The chemical composition of cement is a mixture of calcium aluminum silicate also, a trace amount of Cd, Pb, Fe, Ti and silica. According to several chemical analyses the area surrounding industries show that the further the area is from the factory, the better as soil pollution decreases. In this research paper, we checked the physiochemical pH, electrical conductivity, nitrate ions, sulphate ions, Lead ions and calcium ions content in soil in the Bazian area. The area is far from the surrounding industries and this shows that the further the area is from the factory, the better as soil pollution decreases. There is positive correlation between the calcium ions and electrical conductivity. There is negative correlation between pH and concentration of lead ions. There is also weak correlation between sulphate and nitrate ions concentrations in soil samples.

English

English

Determination of heavy metal ions in vegetable samples using a magnetic metal–organic framework nanocomposite sorbent

This paper describes the synthesis and application of a novel magnetic metal–organic framework (MOF) [(Fe3O4-benzoyl isothiocyanate)/Cu3(benzene-1,3,5-tricarboxylate)2] to pre-concentrate trace amounts of Cd(II), Pb(II), Zn(II) and Cr(III) ions and their determination by flame atomic absorption spectrometry. A Box–Behnken design was used to find the parameters affecting the pre-concentration procedure through response surface methodology. Three factors including uptake time, amount of the magnetic sorbent and pH of the sample were selected as affecting factors in the sorption step, and four factors including type, volume and concentration of the eluent as well as the elution time were selected in the elution step for the optimisation study. The opted values were 30 mg, 10.1 min, 5.9, EDTA, 4.0 ml, 0.57 mol l–1 EDTA solution and 13.0 min for the amount of the magnetic sorbent, uptake time, pH of the sample, type, volume, concentration of the eluent, and elution time, respectively. The limits of detection (LODs) were 0.12, 0.7, 0.16, and 0.4 ng ml−1 for Cd(II), Pb(II), Zn(II) and Cr(III) ions, respectively. The relative standard deviations (RSDs) of the method were less than 7.2% for five separate batch experiments for the determination of 30 μg l−1 of Cd(II), Pb(II), Zn(II) and Cr(III) ions. The sorption capacity of the [(Fe3O4-benzoyl isothiocyanate)/MOF] was 175 mg g−1 for Cd(II), 168 mg g−1 for Pb(II), 210 mg g−1 for Zn(II) and 196 mg g−1 for Cr(III). It was found that the magnetic MOF nanocomposite demonstrated a higher capacity compared with Fe3O4-benzoyl isothiocyanate. Finally, the magnetic MOF nanocomposite was successfully applied to the rapid extraction of trace amounts of the heavy metal ions from vegetable samples.

CLOUD POINT EXTRACTION PROCEDURE FOR FLAME ATOMIC ABSORPTION SPECTROMETRIC DETERMINATION OF HEAVY METALS IN SURFACE SEDIMENTS OF CHAOHU LAKE, CHINA

A cloud point extraction (CPE) procedure for the simultaneous preconcentration of trace amounts of Cd(II), Pb(II), Cu(II), Co(II) and Ni(II) ions as a prior step to their determination by flame atomic absorption spectrometry (FAAS) has been developed. This developed method is based on the formation of hydrophobic complexes of these metals with the chelating agent 1-(2thiazolylazo)-2-naphthol (TAN), which then are entrapped in situ into micellar media of non ionic surfactant octylphenoxypolyethoxyethanol (Triton X-114). Several important variables that affect the complexation and extraction efficiency were investigated and the analytical characteristics of the method were obtained. The interference effect of some anions and cations was also tested. under the optimized conditions, the detection limits for three times the standard deviations of the blank were 1.12, 2.78, 0.77, 1.90 and 1.36 .g/L for Cd(II), Pb(II), Cu(II), Co(II) and Ni(II), respectively, were obtained. The proposed method has been successfully applied to the determination of metal ions in surface sediment samples with satisfactory results.

Solid phase extraction and flame atomic absorption spectrometric determination of trace amounts of cadmium and lead in water and biological samples using modified TiO2 nanoparticles

A solid phase extraction procedure for the separation and preconcentration of trace amounts of Cd(II) and Pb(II) using the alizarin red S modified TiO2 nanoparticles prior to their determination by flame atomic absorption spectrometry has been proposed. The influences of some analytical parameters such as pH, flow rates of sample and eluent, type and concentration of the eluent, and interfering ions on the recovery of Cd(II) and Pb(II) by the sorbent were investigated. The analytes were quantitatively sorbed from the aqueous solution at pH 5.5 onto a microcolumn packed with the sorbent and recovered with 2.0 mL of 1.5 mol L−1 hydrochloric acid. Under the optimum experimental conditions, the detection limits for Cd(II) and Pb(II) were 0.11 and 0.30 ng mL−1 and the relative standard deviations for ten replicate measurements of 5.0 and 50.0 ng mL−1 of Cd(II) and Pb(II) were 2.1 and 1.9%, respectively. A sample volume of 200 mL resulted in a preconcentration factor of 100. The method was successfully applied to the determination of Cd(II) and Pb(II) in water and biological samples, and accuracy was examined by the recovery experiments, independent analysis using electrothermal atomic absorption spectrometry, and analysis of a water standard reference material (SRM 1643e).

A modified nanoporous stir bar for simultaneous determination of Cu(II) and Cd(II) ions in natural samples prior to flame atomic absorption spectroscopy

In this work, the application of stir bar sorptive extraction (SBSE), as a fast and conventional method, has been investigated for the simultaneous preconcentration and determination of trace amounts of Cd(II) and Cu(II) ions in natural samples. For this purpose, the surface of stir bar was functionalized by amine functionalized nanoporous silica and characterized by IR spectroscopy, X-ray powder diffraction (XRD), Atomic force microscopy (AFM) and N2adsorption. In this approach, after the preconcentration of Cd(II) and Cu(II) ions and removing the matrix interferences using modified stir bar, the amounts of these ions were determined in eluent by flame atomic absorption spectroscopy (FAAS). Various parameters on adsorption and elution steps including pH of sample, adsorption kinetic, eluent parameters (type, volume and concentration) and elution time, have been optimized in this study. The limits of detection (LOD) were 1.6 and 13.8 ng mL-1(recovery of 83.5 and 88.1%) for cadmium and copper ions, respectively. The preconcentration factors were 133 and 137 and the relative standard deviations (RSD) of the method were 5.7 and 4.6% for Cd(II) and Cu(II) ions, respectively. As the key point in this study seems to be stir bar nanoporous structure, the analytical performance of this stir bar was compared to non-porous ones. The accuracy of this novel method has been confirmed using some standard references materials. Finally the potential of this method was investigated by determination of Cd(II) and Cu(II) ions in some real samples with complicated matrixes.

Cadmium stabilization with nursery stocks through transplantation: A new approach to phytoremediation

Disposal of heavy metal contaminated biomass after phytoremediation is still unfeasible. This paper presents a viable phyto-extraction approach in which metals in contaminated soils are stabilized by nursery stocks before transplantation for greening. In this respect, two pot-experiments are reported comparing seven nursery stocks species exposed to different Cd levels. The first experiment revealed that Cd was mainly stabilized in the roots of all species studied. Greater amounts of Cd were accumulated in the epidermis than cortex plus stele. Cupressus Blue Ice showed greatest tolerance to the 100 and 200 mg kg −1 Cd stresses. The second experiment additionally evaluated the possible risk of Cd release after transplanting the Cd treated plants into uncontaminated soil. After 120 days of transplantation, the relatively trace amounts of Cd in the roots of Euonymus japonicus, Pittosporum tobira and C. Blue Ice had either been partially transferred into the shoots or released into the soil. The highest Cd concentration increase in bulk soil (0.428 mg kg −1), however, was much lower than the environmental quality standard for soils of China (1 mg kg −1). The potential effectiveness of this technique in the use of Cd-contaminated soil and further investigation needed in the field trials were also evaluated.

Heavy metals accumulation effect in rabbit body fluids after smoking

Concentration of heavy metals in blood and urine of rabbit after inhaling three different kinds of cigarette was studied through the animal passive smoking pattern. The samples were prepared by nitric acid solution digestion and determination of seven kinds of heavy metals including Hg, Se, Sn, Pb, Cd, Ni and Cr was performed by inductively coupled plasma-atomic emission spectrometry (ICP-AES). The ICP-AES method was established with good precision and accuracy, relative standard deviation (n=6) was between 2.9% and 5.9%, and the recovery was in the range of 95.0%–104.2%. Concentration of six heavy metals increases in some extent in blood and urine after period of smoking and the increasing of heavy metals in blood and urine all shows time dependence. Significantly higher heavy metal levels are observed in the blood and urine of the cigarette inhaling rabbits in the exposed group. The concentration of six kinds of heavy metals in the blood of the rabbit increases after 16 weeks exposing to cigarette smoking. Three times of Hg, ten times of Se and trace amount of Pb, Cd, Ni and Cr are detected in the blood after 16 weeks of smoking. For urine samples, about three times of Hg, two times of Se, five times of Pb and trace amount of Cd are detected after 16 weeks of inhalation of cigarette. Comparatively, higher concentration of heavy metals are detected after inhaling of Nise cigarette.

Dissolution of Low Iron Sphalerite in Ferric Sulphate-Sulphuric Acid Media

The dissolution of low iron sphalerite, nominally ZnS but also containing 0.08 Fe and trace amounts of Cd and Mn, in ferric sulphate-sulphuric acid media was investigated using closely sized fractions of crushed sphalerite crystals and sintered disks made from the crushed crystals. Linear kinetics are observed and the predominant reaction products are ZnSO4, FeSO4 and elemental sulphur. The leaching rate increases systematically with increasing temperature and the calculated apparent activation energy is 56 kJ/mol for the sized sphalerite and 54 kJ/mol for the sintered disks. The relatively high apparent activation energy suggests that the rate is chemically controlled, a conclusion supported by the insensitivity of the rate to the disk rotation speed. The rate increases as the 0.22 power of the Fe(SO4)1.5 concentration and as the 0.22 power of the H2SO4 concentration. However, in the absence of ferric ions, the rate increases more significantly with increasing H2SO4 concentrations and relatively rapid rates are observed in solutions containing >0.5 M H2SO4. In 0.1 M Fe(SO4)1.5-0.3 M H2SO4 media, the measured rate decreases with increasing sulphate concentrations, added as Li2SO4. The rate of dissolution of low iron sphalerite is promoted by dissolved copper concentrations as high as 800 mg/L. In contrast, dissolved silver, even in the 0-2 mg/L concentration range, significantly retards the dissolution of the low iron sphalerite.

Abstracts of Nippon Dojo-Hiryogaku Zasshi

Abstracts of Nippon Dojo-Hiryogaku Zasshi

Does salicylic acid regulate antioxidant defense system, cell death, cadmium uptake and partitioning to acquire cadmium tolerance in rice?

Salicylic acid (SA) may accelerate the cell death of cadmium-stressed roots to avoid cadmium (Cd) uptake by plants or may play positive roles in protecting the stressed roots from Cd-induced damage. To test these hypotheses, we performed a series of split-root hydroponic experiments with one-half of rice (Oryza sativa L. cv. Jiahua 1) roots exposed to 50 microM Cd and the other half not exposed. The objectives were to elucidate the effects of SA pretreatment on the time-dependent changes of H(2)O(2) levels in roots, antioxidant defense system in different organs, root cell death and the dynamic distribution of Cd in the plants. In the split-root system, a higher Cd uptake rate was observed in the Cd-stressed portions of roots compared with the treatment with the whole roots exposed to Cd. Furthermore, an appreciable amount of Cd was translocated from the Cd-exposed roots to the unexposed roots and trace amounts of Cd were released into the external solution. The split-root method also caused the two root portions to respond differently to Cd stress. The activities of major antioxidant enzymes (superoxide dismutase, SOD; peroxidase, POD; and catalase, CAT) were significantly suppressed in the Cd-treated roots, hence leading to H(2)O(2) burst, lipid peroxidation, cell death and growth inhibition. By contrast, in the non-Cd-treated roots, the activities of enzymes (SOD, CAT, and POD) and root growth were persistently stimulated during the experimental period. The H(2)O(2) accumulation and lipid peroxidation were also induced in the non-Cd-treated roots, but they were significantly lower than those of the Cd-treated roots. The concentrations of glutathione (GSH) and non-protein thiols (NPT) in the Cd-treated roots were significantly higher than those of the untreated roots. SA pretreatment elevated enzymatic and non-enzymatic antioxidants, and the concentrations of GSH and NPT in roots and shoots, hence leading to alleviation of the oxidative damage as indicated by the lowered H(2)O(2) and MDA levels. Furthermore, SA pretreatment mitigated the Cd-induced growth inhibition in both roots and shoots and increased transpiration compared with non-SA-pretreatment under Cd exposure. It is concluded that Cd can be partly transferred from the Cd-exposed roots to Cd-unexposed roots and that cell death can be accelerated in the Cd-stressed roots in response to Cd stress. The SA-enhanced Cd tolerance in rice can be attributed to SA-elevated enzymatic and non-enzymatic antioxidants and NPT, and to SA-regulated Cd uptake, transport and distribution in plant organs.

A Preconcentration Procedure Using 1-(2-Pyridylazo)-2-napthol Anchored to Silica Nanoparticle for the Analysis of Cadmium in Different Samples

A new analytical method using 1-(2-pyridylazo)-2-naphthol modified SiO2nanoparticles as solid-phase extractant has been developed for the preconcentration of trace amounts of Cd(II) in different water samples. Conditions of the analysis such as preconcentration factor, effect of pH, sample volume, shaking time, elution conditions and effects of interfering ions for the recovery of analyte were investigated. The adsorption capacity of nanometer SiO2-PAN was found to be 60.57 μmol/g at optimum pH and the detection limit (3σ) was 0.76 μg/L. The extractant showed rapid kinetic sorption. The adsorption equilibrium of Cd(II) on nanometer SiO2-PAN was achieved just in 15 minutes. Adsorbed Cd(II) was easily eluted with 6 mL of 6 M hydrochloric acid. The maximum preconcentration factor was 50. The method was applied for the determination of trace amounts of Cd(II) in various synthetic samples and water samples.