磁性纳米粒子富集-电感耦合等离子体发射光谱法测定食具中铬、镍、镉、铅、砷的迁移量

采用氩电弧等离子体法制备磁性碳包铁纳米粒子,考察了其对水溶液中Cr,Ni,Cd,Pb和As的富集能力,建立电感耦合等离子体原子发射光谱同时测定食具中Cr,Ni,Cd,Pb和As迁移量的分析方法。研究了纳米粒子表面经H2O2处理后,pH值、吸附时间、吸附剂用量等因素对各元素富集效率的影响。结果表明,H2O2表面处理可有效提高纳米粒子对待检元素的吸附率。在pH 8.0～9.5范围内,选用30 mg碳包铁纳米粒子定量富集,振荡3 min后,Cr,Ni,Cd,Pb和As均可被磁性碳包铁纳米粒子定量富集,酸性溶液(pH 1～2)可洗脱吸附离子。采用本方法测定了实际样品,各元素回收率在87%～106%之间。     

络合吸附伏安法同时测定多种重金属离子

在络合剂亚硝基苯胲 乙醇 乙酸铵体系中,Cr(Ⅵ)、Cd2 、Cu2 、Pb2 、Ni2 等离子都能在汞电极上产生灵敏的阴极络合吸附波,其二次导数伏安峰电流均与离子质量浓度有良好的线性关系,可用于这些离子的定量检测,测定线性范围为Cr(Ⅵ)0.0017～0.67μg mL、Cd2 0.0017～0.117μg mL、Cu2 0.0083～5 8μg mL、Pb2 0.083～1.25μg mL、Ni2 0.17～150μg mL,RSD分别为5.7%、1 3%、1.4%、2 5%和1.6%。方法为工业废水、地表水及生活用水等样品中重金属离子的同时测定提供了可靠、灵敏的检测方法。     

巯基功能化金纳米搅拌棒的制备及其对Pb(Ⅱ)和Cd(Ⅱ)的吸附检测

为实现金纳米粒子(AuNPs)对环境水体中重金属离子的选择性吸附,以刻饰不锈钢丝为基体,采用化学沉积法在刻蚀不锈钢丝表面沉积AuNPs,再用自组装法将1,8-辛二硫醇修饰于AuNPs上,制备了一种以巯基功能化金纳米为吸附剂的金属搅拌棒(AuNPs-SH-SBSE)。采用电感耦合等离子发射光谱仪(ICPOES)为检测手段,以常见的金属离子Pb(Ⅱ)和Cd(Ⅱ)为例,评价了金属搅拌棒的萃取分离性能。考察了吸附时间、pH值、解吸溶剂等因素对Pb(Ⅱ)和Cd(Ⅱ)吸附率的影响。结果表明,当吸附平衡时间为30min、pH 8.0,6.0 mL 1.5 mol/L HNO_3作洗脱剂时,Pb(Ⅱ)和Cd(Ⅱ)的吸附率分别达98.5%和87.4%。将该方法用于实际样品中痕量Pb(Ⅱ)和Cd(Ⅱ)的吸附检测,其线性范围分别为0.1~50 mg/L和0.2~20 mg/L,方法的检出限(S/N=3)分别为24 ng/L和3.6μg/L。在低、高2个浓度水平下进行加标回收实验,回收率分别为85.4%~105.0%和74.2%~97.8%,相对标准偏差(RSD,n=3)分别为3.8%~8.2%和4.2%~10.6%。该方法简单、快速、灵敏,可应用于环境水体中Pb(Ⅱ)和Cd(Ⅱ)的分离检测。     

聚苯乙烯-丙烯醛-氨基硫脲/纳米二氧化钛复合固相萃取填料的制备及其性能

以苯乙烯,甲基丙烯醛等为原料,采用分散聚合法制备聚苯乙烯-丙烯醛。将该聚合物与氨基硫脲反应,制备聚苯乙烯-丙烯醛-氨基硫脲。以钛酸丁酯为原料合成的纳米二氧化钛,采用溶液共混法制备聚合物/纳米二氧化钛复合固相萃取填料。采用红外光谱法、扫描电镜、热重分析、X射线光电子能谱、X射线衍射分析仪对该复合材料进行了表征和分析。考察了合成的固相萃取填料对Cr,As,Cd和Pb离子的吸附性能,其吸附容量分别为15.42,11.20,16.21和16.42 mg/g。将SPE与ICP-M S联用,测定了猪肉中Cr,As,Cd和Pb含量,检出限分别为0.046,0.21,0.012和0.057μg/kg,相对标准偏差分别为3.6%,2.0%,3.2%和1.4%。     

聚合物整体柱毛细管微萃取-电感耦合等离子体质谱分析生物样品中的痕量重金属离子

制备了聚(丙烯酰胺-乙二醇二甲基丙烯酸酯)(Poly(AA-EGDMA))整体柱,采用红外(IR)光谱、扫描电子显微镜(SEM)对其结构和形貌进行了表征。基于此,建立了Poly(AA-EGDMA)整体柱毛细管微萃取(CME)-等离子体质谱(ICP-MS)联用检测生物样品中痕量重金属离子的分析方法。对影响CME的诸多条件,如样品溶液的pH值、上样体积、上样流速、解吸剂浓度及体积、解吸剂流速以及共存离子的干扰等进行了详细的考察。在优化的实验条件下,方法对Cd2+和Pb2+的检出限分别为4ng·L-1和36ng·L-1,相对标准偏差(c=0.2μg·L-1,n=7)分别为4.7%和3.9%。该整体柱对Cd2+和Pb2+的吸附容量分别为46.7μg·m-1和130μg·m-1。将所建立的方法用于尿样中痕量重金属离子Cd2+、Pb2+的测定,加标回收率分别为99%和100%。     

电感耦合等离子体质谱法测定铅锌矿尾矿渣中铜、铅、锌和镉

采用硝酸-氢氟酸-高氯酸溶解样品,用电感耦合等离子体质谱法测定了铅锌矿尾矿渣中的铜、铅、锌和镉。以铑为内标元素,选择63 Cu,66Zn,208 Pb,114 Cd作为测量同位素。铜、铅、锌的线性范围为200μg·L-1,镉的线性范围为1.0μg·L-1,检出限(3s)分别为0.04,0.10,0.03,0.003μg·g-1。测定值的相对标准偏差(n=11)在0.39%~2.2%之间。用此方法分析标准物质,测定值与认定值相符。     

纳米SiO_2分离富集-火焰原子吸收法测定水中痕量银

研究了纳米SiO_2分离富集-火焰原子吸收法测定水中痕量银的新方法.考察了溶液pH、吸附时间、洗脱条件和干扰离子等因素对Ag~+分离富集的影响,确定了纳米SiO_2对Ag~+吸附的最佳条件.结果表明:在pH 4.1时,纳米SiO_2能定量吸附银,吸附在纳米SiO_2上的Ag~+可用0.5 mol/L HCl+0.5 mol/L硫脲定量洗脱.该法对银的检出限为0.77 ng/mL(3σ,n=11);线性范围为0.005～1.5μg/mL,对0.5μg/mL的Ag~+标液进行7次测定,RSD为3.6%,回收率在94.0%～101.5%之间;方法可用于环境水样中痕量银的测定.     

基于锑薄膜覆盖铅笔芯电极对Cd(Ⅱ)和Pb(Ⅱ)高灵敏度的检测(英文)

在铅笔芯上通过实时沉积锑薄膜,使用方波阳极溶出伏安法(SWASV)对Cd(Ⅱ)和Pb(Ⅱ)进行同时检测.沉积时间为180 s时,Cd(Ⅱ)和Pb(Ⅱ)的最低检测限分别为0.075μg·L-1和0.13μg·L-1,较铋膜修饰的铅笔芯电极低.在低pH值溶液(pH 2.0)中重现性好.该电极可成功用于测定自来水中的Cd(Ⅱ)和Pb(Ⅱ)含量.     

二硫代乙二酰胺改性硅胶固相萃取-火焰原子吸收光谱法测定水中的痕量铜和铅

制备了二硫代乙二酰胺改性硅胶作为固相萃取吸附剂,在pH 5.2,吸附时间为40min时,得到Cu2+、Pb2+的最大静态吸附容量,分别为19.50,29.39mg·g-1。水样中痕量的Cu2+、Pb2+经固相萃取后采用火焰原子吸收光谱法测定。在最佳条件下,Cu2+、Pb2+的线性范围分别为1.0~100,10~300μg·L-1,检出限(3S/N)分别为0.7,5.0μg·L-1。加标回收率在97.6%~104%之间。方法用于分析标准模拟水样,测定值与认定值相符。     

活性炭在富集水中痕量重金属中的研究及应用

采用微波等离子体原子发射光谱仪(MP-AES)研究了活性炭对水中微量重金属的富集性能,实现了一种简单有效,能够同时富集痕量Zn(Ⅱ),Cd(Ⅱ),V(Ⅲ),Co(Ⅱ),Ni(Ⅱ),Pb(Ⅱ),Mn(Ⅱ)和Cr(Ⅲ)8种重金属的方法。实验优化了预富集条件,包括p H值、填料量、样品速率、样品体积和洗脱条件,同时考察了常见干扰离子的影响,结果显示常见干扰离子对分析物的回收率无影响。在最优条件下,该方法对Zn(Ⅱ),Cd(Ⅱ),V(Ⅲ),Co(Ⅱ),Ni(Ⅱ),Pb(Ⅱ),Mn(Ⅱ)和Cr(Ⅲ)的检出限分别为0.45,0.35,0.25,0.06,0.40,0.25,0.20,0.20μg·L-1。该方法对10μg·L-1分析物测定的相对标准偏差(RSD,n=8)均小于5.0%。V(Ⅲ),Pb(Ⅱ)和Cr(Ⅲ)的最大富集因子为50;其他5种金属离子的最大富集因子不小于300。利用标准物质对该方法进行验证,并对实际环境水样进行测定,结果令人满意。     

Sol-gel zirconia coating capillary microextraction on-line hyphenated with inductively coupled plasma mass spectrometry for the determination of Cr, Cu, Cd and Pb in biological samples

A sol-gel zirconia coating was developed for the preconcentration/separation of trace Cr, Cu, Cd and Pb by capillary microextraction, and the adsorbed analytes were on-line eluted for detection using inductively coupled plasma mass spectrometry (ICP-MS). By immobilizing sol-gel zirconia on the inner surface of a fused-silica capillary, the sol-gel zirconia coating was simply prepared. Its adsorption properties, stability and the factors affecting the adsorption behaviors of Cr, Cu, Cd and Pb were investigated in detail. In the pH range from 7.8 to 10, the zirconia-coated capillary (35 cm x 0.15 mm) is selective towards Cr, Cu, Cd and Pb, and the analyzed ions could be desorbed quantitatively with 0.2 mL of 0.5 mol/L HNO(3) at a rate of 0.2 mL/min. With a consumption of 1.25 mL sample solution, an enrichment factor of 6.25, and detection limits (3sigma) of 9.9 pg/mL Cr, 17.9 pg/mL Cu, 4.5 pg/mL Cd and 3.7 pg/mL Pb were obtained. The precisions for nine replicate measurements of 1 ng/mL Cr, Cu, Cd and Pb were 4.9% Cr, 2.2% Cu, 2.0% Cd and 3.2% Pb (RSD), respectively. The proposed procedure has been applied to the determination of Cr, Cu, Cd and Pb in human urine, which was subjected to microwave-assisted digestion prior to analysis, and the recoveries for these elements were 89.2-101.8%. In order to validate the developed procedure, a NIES No.10-a Rice Flour-Unpolished certified reference material and a BCR No. 184 Bovine Muscle certified reference material were analyzed, and the results are in good agreement with the certified values.     

Adsorption of heavy metal ions onto dithizone-anchored poly (EGDMA-HEMA) microbeads

The dithizone-anchored poly (EGDMA-HEMA) microbeads were prepared for the removal of heavy metal ions (i.e. cadmium, mercury, chromium and lead) from aqueous media containing different amounts of these ions (25-500 ppm) and at different pH values (2.0-8.0). The maximum adsorptions of heavy metal ions onto the dithizone-anchored microbeads from their solutions was 18.3, Cd(II); 43.1, Hg(II); 62.2, Cr(III) and 155.2 mg g(-1) for Pb(II). Competition between heavy metal ions (in the case of adsorption from mixture) yielded adsorption capacities of 9.7, Cd(II); 28.7, Hg(II); 17.6, Cr(III) and 38.3 mg g(-1) for Pb(II). The same affinity order was observed under non-competitive and competitive adsorption, i.e. Cr(III)>Pb(II)>Hg(II)>Cd(II). The adsorption of heavy metal ions increased with increasing pH and reached a plateaue value at around pH 5.0. Heavy metal ion adsorption from artificial wastewater was also studied. The adsorption capacities are 4.3, Cd(II); 13.2, Hg(II); 7.2, Cr(III) and 16.4 mg g(-1) for Pb(II). Desorption of heavy metal ions was achieved using 0.1 M HNO(3). The dithizone-anchored microbeads are suitable for repeated use (for more than five cycles) without noticeable loss of capacity.     

Sulfur-nanoparticle-based method for separation and preconcentration of some heavy metals in marine samples prior to flame atomic absorption spectrometry determination

The application of sulfur-nanoparticle-loaded alumina as an efficient adsorbent for the solid-phase extraction (SPE) and determination of trace amounts of Cd, Cu, Zn, and Pb ions was investigated in marine samples using flame atomic absorption spectrometry (FAAS). The nanometer-sized sulfur particles were synthesized in situ, physically loaded onto alumina microparticles, and the parameters influencing the preconcentration of the analytes, such as the pH, solution flow rate and volume, eluent solution, and interfering ions, were examined. The results showed that the optimal conditions for quantitative recovery of the metal ions by adsorption and elution on the sulfur nanoparticles (SNPs) was achieved by employing a flow rate of 15 mL min(-1), a pH of 8.5 for the sample solutions, and an eluent composed of 3.0 mol L(-1) HNO(3) in methanol. The detection limits of this method for Cd, Zn, Cu, and Pb ions were 0.30, 0.21, 0.24, and 0.63 μg L(-1) (n=10), respectively. Application of the proposed method to the analysis of fish certified reference material (DORM-3) produced results that were in good agreement with the certified values. The proposed method was also successfully applied to the determination of analytes in marine samples, including seawater, fish, and oysters.     

Adsorptive accumulation of Cd(II), Co(II), Cu(II), Pb(II), and Ni(II) from water on montmorillonite: influence of acid activation

The present work investigates the influence of acid activation of montmorillonite on adsorption of Cd(II), Co(II), Cu(II), Ni(II), and Pb(II) from aqueous medium and comparison of the adsorption capacities with those on parent montmorillonite. The clay-metal interactions were studied under different conditions of pH, concentration of metal ions, amount of clay, interaction time, and temperature. The interactions were dependent on pH and the uptake was controlled by the amount of clay and the initial concentration of the metal ions. The adsorption capacity of acid-activated montmorillonite increases for all the metal ions. The interactions were adsorptive in nature and relatively fast and the rate processes more akin to the second-order kinetics. The adsorption data fitted both Langmuir and Freundlich isotherms, indicating that strong forces were responsible for the interactions at energetically nonuniform sites. The Langmuir monolayer capacity of the acid-activated montmorillonite is more than that of the parent montmorillonite (Cd(II): 32.7 and 33.2 mg/g; Co(II): 28.6 and 29.7 mg/g; Cu(II): 31.8 and 32.3 mg/g; Pb(II): 33.0 and 34.0 mg/g; and Ni(II): 28.4 and 29.5 mg/g for montmorillonite and acid-activated montmorillonite, respectively). The thermodynamics of the rate processes showed the adsorption of Co(II), Pb(II), and Ni(II) to be exothermic, accompanied by decreases in entropy and Gibbs free energy, while the adsorption of Cd(II) and Cu(II) was endothermic, with an increase in entropy and an appreciable decrease in Gibbs free energy. The results have established the potential use for montmorillonite and its acid-activated form as adsorbents for Cd(II), Co(II), Cu(II), Ni(II), and Pb(II) ions from aqueous media.     

复合塑料包装袋中重金属迁移量的测定

将复合塑料袋用4％乙酸浸泡,采用石墨炉原子吸收光谱仪对其中的铅、镉、铬、镍、铜、砷迁移量进行了测定.结果表明:各元素的吸光度与质量浓度呈良好的线性关系,相关系数为0.998 9～0.9999,元素Pb、Cd、Cr、Ni、Cu、As的检出限分别为1.04、0.05、0.98、1.00、0.97、0.96 μg/L,各元素...     

Determination of trace elements in automotive fuels by filter furnace atomic absorption spectrometry

The determination of Cd, Cr, Cu, Pb and Ni was performed in gasoline and diesel fuel samples by electrothermal atomic absorption spectrometry using the Transverse Heated Filter Atomizer (THFA). Thermal conditions were experimentally defined for the investigated elements. The elements were analyzed without addition of chemical modifiers, using organometallic standards for the calibration. Forty-microliter samples were injected into the THFA. Gasoline samples were analyzed directly, while diesel fuel samples were diluted 1:4 with n-heptane. The following characteristic masses were obtained: 0.8 pg Cd, 6.4 pg Cr, 12 pg Cu, 17 pg Pb and 27 pg Ni. The limits of determination for gasoline samples were 0.13 μg/kg Cd, 0.4 μg/kg Cr, 0.9 μg/kg Cu, 1.5 μg/kg Pb and 2.5 μg/kg Ni. The corresponding limit of determination for diesel fuel samples was approximately four times higher for all elements. The element recovery was performed using the addition of organometallic compounds to gasoline and diesel fuel samples and was between 85 and 105% for all elements investigated.     

石英与水溶液作用的界面反应特征

矿物表面因存在有各种悬空键 ,而形成了表面活性官能团 ,称作“表面位”。对石英来说 ,表面氧离子可以与水中Ｈ+和ＯＨ- 离子反应 ,使表面产生荷电性。研究表明[1 ,2 ] ,石英对二价金属离子的吸附反应遵循Ｆｒｅｕｄｌｉｃｈ方程 ,本文在分析石英表面位及其质子化反应、表面位与重金属离子反应的基础上 ,进一步探讨石英与水溶液作用的界面反应特征及其影响因素。1　实验材料与方法石英粉末样品用王水煮洗 ,后用纯净水浸洗至无ＡｇＣｌ,过滤、1 1 0℃烘干、450℃煅烧 1 2ｈ。经ＮＯＶＡ 1 0 0 0ＶＥＲ3.7自动表面分析仪 (Ｎ2 ＢＥＴ法 )测定…     

笼形聚氨肟树脂的研究：碱处理对吸附性能的影响

研究碱处理的笼形聚氨肟树脂（ＢＣＡＯ）对二价金属离子的吸附行为。吸附结果若生成２：１配的，得Ｍｇ＾２＋，Ｃａ＾２＋，Ｂａ＾２＋，Ｍｎ＾２＋，Ｃｏ＾２＋，Ｎｉ＾２＋，Ｚｎ＾２＋，Ｃｄ＾２＋，Ｐｂ＾２＋，Ｃｕ＾２＋离子的吸附效率分别是２７．１、２９．２、３０．４、２９．０、２７．１、３０．８、４５．０、３９．８、６０．３、６２．１％，Ｈｇ＾２＋离子的吸附效率高达１０５％，表明在吸附过程中同时生成２：１     

Preparation and characterization of porous calcium titanate-based coated glass fiber filter material and its application in determination of lead and cadmium ion concentrations in water

Glass fiber filter coated with a porous block adsorption agent of calcium titanate (GPCTO) was prepared by the citric acid sol-gel method, and characterized by X-ray diffraction, scanning electron microscopy, and FTIR spectrophotometry. Its Pb2+ and Cd2+ adsorption properties from water were studied. Adsorption and elution were investigated under different conditions, as were the thermodynamics and kinetics of adsorption, using Cd ion as representative. Calcium titanate may react with glass fiber, forming Si-O-Ti and B-O-Ti bonds and becoming a composite adsorbent. The Pb and Cd ions were quantitatively retained at pH 4-9; their adsorption capacities by the GPCTO were 199.72 and 19.68 mg/g, respectively. The isothermal data were described by the Langmuir equation. The dynamic data followed the pseudo-second-order kinetic model well. The enthalpy change (AH) of the adsorption process was 37.160 kJ/mol. At various temperatures, Gibbs free energy changes (delta G) were negative, and entropy changes (delta S) were positive. The activation energy (Ea) was 38.127 kJ/mol for the adsorption. Cd ion adsorption by the GPCTO was endothermic and spontaneous. The adsorbed Pb and Cd ions were completely recovered by elution with 2 M HNO3. The Pb+ and Cd2+ concentration factors were up to 200. The method has been applied to the preconcentration for flame atomic absorption spectrometric determinations of trace Pb and Cd ions in water samples. The recoveries were 95.2 to 102.4% for Pb and 92.2 to 98.0% for Cd.