双硫腙修饰纳米TiO2分离富集石墨炉原子吸收光谱法测定水样中痕量金属离子

建立了双硫腙修饰纳米TiO2分离富集-石墨炉原子吸收光谱法测定水样中痕量镉、铬和铅的新方法,优化了纳米TiO2-双硫腙对试样中这3种痕量物质的吸附和解吸条件。结果表明,在pH 5.0时,镉、铬和铅可被定量吸附,静态饱和吸附容量分别为13.3、5.5、21.8 mg/g。吸附的各种金属离子可用5 mL 0.1mol/L的硝酸完全洗脱。该方法对Cd2+、Cr3+和Pb2+的检出限(3σ,n=11)分别为0.18、0.51、1.92 ng/L,相对标准偏差分别为2.8%、2.3%和1.0%,加标回收率为96%～101%。该方法已成功应用于环境水样中镉、铬和铅的测定。     

石墨炉原子吸收法测定美白化妆品中铅和镉

本文采用石墨炉原子吸收法测定了美白化妆品中铅、镉含量.铅、镉测定的线性范围分别为0～176 ng/mL、0～88 ng/mL,相关系数r均为0.9998,回收率分别为98.2%～101.1%和98.9%～101.8%,相对标准偏差分别为1.73%和1.46%.     

石墨炉原子吸收光谱法测定新疆出口番茄酱中的铅和镉

报道了微波消解石墨炉原子吸收光谱法测定番茄酱中的铅、镉。研究了石墨炉原子吸收测定的最佳条件。该方法测定铅和镉的线性范围分别为0.00~25 ng/mL、0.00~8 ng/mL;相对标准偏差分别为2.15%、3.10%;回收率分别为98.6%、104.5%。利用国家标准物质番茄叶(ESP-1)验证了方法的准确度,测定值与标准值基本吻合。研究表明,该方法具有很好的准确度和精密度。     

微波消解-石墨炉原子吸收法测定酵母粉中的微量铅和镉

本文采用微波消解-石墨炉原子吸收法直接测定酵母粉中微量铅和镉的含量。利用硝酸和过氧化氢消解样品,对微波消解的条件,基体改进剂的选择,铅原子化温度的效果以及常见元素对测定的干扰进行了研究。在优化的实验条件下,方法对铅和镉的检出限(3σ)分别为0.062 ng/mL和0.013 ng/mL,相对标准偏差(RSD)分别为0.64%~1.11%、0.75%~4.70%,加标回收率在95.00%~102.0%之间。本法已用于酵母粉中微量铅和镉的测定,分析结果与电感耦合等离子体-质谱(ICP-MS)法具有良好的一致性。     

螺旋藻中铅镉的ICP-MS测定

采用微波消解、高压罐消化以及HNO3 HClO4消化3种方法对螺旋藻样品进行处理,比较了不同方法产生的空白值和加标回收率。建立了微波消解-电感耦合等离子体质谱法测定螺旋藻样品中的铅镉的方法。铅镉检出限分别为0.06ng mL和0.05ng mL,RSD均小于3%,加标回收率在98%～101%之间。方法用于实际样品分析。     

间断多次扫描电位溶出分析方法的研究

间断多次扫描电位溶出分析是在多次扫描电位溶出分析和间断扫描伏安法的基础上提出的一种新的电位溶出分析技术,它不仅具有多次扫描电位溶出分析灵敏度高的优点,又克服了多次扫描电位溶出分析对多元素分析时元素之间相互干扰的缺点。文章讨论了间断多次扫描电位溶出分析的实验条件,同时用这种方法分析了人尿中镉、铅的含量。间断多次扫描电位溶出分析在电积10分钟时,最低可检测到0.005ng/mL的镉和0.01ng/mL的铅。镉、铅浓度为4ng/mL时,相对标准偏差分别为2.9%和3.2%,证明间断多次扫描电位溶出分析可以同脉冲阳极溶出伏安法媲美。     

石墨炉原子吸收法测定食品添加剂甲壳素中的镉和铅

采用程序控制温度,一次完成甲壳素样品的炭化和灰化,通过氢氟酸-硝酸消除灰分中硅的干扰,用石墨炉原子吸收法直接测定其中的镉和铅.镉的浓度在0～50 ng/mL范围内与吸光度呈良好的线性关系,相关系数r= 0.9990;铅的浓度在0～300 ng/mL范围内与吸光度呈良好的线性关系,相关系数r=0.9990 .镉的回收率为90.6%～102.0%,测定结果的相对标准偏差为4.37%(n=8);铅的回收率为91.3%～102.1%,测定结果的相对标准偏差为8.67%(n=8).     

顶空固相微萃取-气相色谱质谱联用测定烷基铅的研究

建立了顶空固相微萃取(HS SPME)与气相色谱 质谱(GC/MS)联用测定水样中四甲基铅和四乙基铅的方法,探讨了SPME萃取烷基铅的实验条件,并对GC/MS条件进行了优化。结果表明:四甲基铅和四乙基铅分别在5～1000ng/mL和1～500ng/mL范围内有良好的线性关系,检出限分别为四甲基铅5.19ng/mL,四乙基铅1.05ng/mL。方法用于合成水样分析,四甲基铅和四乙基铅的回收率在87.5%～110.6%之间,相对标准偏差在1.7%～6.5%之间。     

微波消解石墨炉原子吸收法测定人发中的铅、镉

采用石墨炉原子吸收分光光度法(GFAAS)测定人发中的铅、镉含量.采用微波消解法消解样品,加入(NH4)2SO4+KH2PO4基体改进剂消除干扰,对消化剂种类、消解压力、仪器条件等进行了探索.方法简便、准确度高,Pb和Cd的平均回收率分别为101.8%和107.1%,相对标准偏差(RSD)为5.14%和6.80%,方法检出限Pb为9.53 ng/mL,Cd为0.78 ng/mL.     

血液与尿液中铅形态化合物的HPLC-ICP-MS分析

建立了血液和尿液中2种铅形态化合物(三甲基铅、三乙基铅)的高效液相色谱-电感耦合等离子体质谱(HPLC-ICP-MS)分析方法。利用苯溶液萃取铅形态化合物,超声离心后以硫代硫酸钠溶液进行反萃取。以0.1 mol/L乙酸铵-0.1 mol/L乙酸与甲醇为流动相进行等度洗脱,Agilent Zorbax Plus C_(18)(4.6 mm×100 mm,3.5μm)对提取物进行分离,ICP-MS分析样品中铅形态化合物。结果表明,血液和尿液中2种铅形态化合物的线性范围分别为3～200 ng/mL和5～400 ng/mL,检出限为0.85～1.31 ng/mL,定量下限为3.00～5.00 ng/mL,日内及日间相对标准偏差(RSD)为1.8%～10%,提取回收率为85.3%～104%,基质效应为88.3%～117%。该方法样品前处理简单,检出限低,准确度高,适用于人体血液和尿液中三甲基铅、三乙基铅的测定。     

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.     

A pre-enrichment procedure using diethyldithiocarbamate-modified TiO2 nanoparticles for the analysis of biological and natural water samples by ICP-AES

In this article, a new method that utilizes a diethyldithiocarbamate-modified nanometre TiO₂ (TiO₂–DDTC) as solid-phase extractant has been developed for simultaneous preconcentration of trace Cu(II), Pb(II), Zn(II), and Cd(II) prior to measurement by inductively coupled plasma atomic emission spectrometry (ICP-AES). The separation/preconcentration conditions of analytes, which include the effects of pH, sample flow rate and volume, elution conditions, and interfering ions on the recovery of the analytes, were investigated. At pH 5, the adsorption capacity of modified nanometre TiO₂–DDTC was found to be 6.2, 19, 4.7, and 6.0?mg/g for Cu(II), Pb(II), Zn(II), and Cd(II), respectively. According to the definition of IUPAC, the detection limits (3σ) of this method for Cu(II), Pb(II), Zn(II), and Cd(II) were 0.41, 1.7, 0.39, and 0.52?ng/mL, respectively. The proposed method achieved satisfied results when applied to the determinations of trace Cu(II), Pb(II), Zn(II), and Cd(II) in biological and natural water samples.     

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).     

Selective solid phase extraction of trace cadmium(II) and lead(II) from biological and natural water samples by ofloxacin-modified-silica gel

Ofloxacin was successfully used as a chemical modifier to improve the reactivity of silica gel in terms of selective binding and extraction of heavy metal ions. This new functionalised silica gel (SG-ofloxacin) was as an effective sorbent for the solid-phase extraction (SPE) of Cd(II) and Pb(II) in biological and natural water samples and their determination by inductively coupled plasma optical emission spectrometry (ICP-OES). Experimental conditions for effective adsorption of trace levels of Cd(II) and Pb(II) were optimised with respect to different experimental parameters using the batch and column procedures. The time for 70% sorption for Cd(II) and Pb(II) was less than 2 min. Complete elution of the adsorbed metal ions from the SG-ofloxacin was carried out using 2.0 mL of 0.5 mol L^?1 of HCl. Common coexisting ions did not interfere with the separation and determination at pH 4.0. The maximum static adsorption capacity of the sorbent at optimum conditions was found to be 39.17 and 48.69 mg g^?1 for Cd(II) and Pb(II), respectively. The detection limits of the method were found to be 0.29 and 0.13 ng mL^?1 for Cd(II) and Pb(II), respectively. The relative standard deviation (RSD) of the method under optimum conditions was lower than 3.0% (n = 5). The method was applied to the recovery of Cd(II) and Pb(II) from the certified reference material (GBW 08301, river sediment) and to the simultaneous determination of these cations in different water and biological samples with satisfactory results and yielding 100-folds enrichment factor.     

Stripping Voltammetric Determination of Pb(II) and Cd(II) Based on the Multiwalled Carbon Nanotubes-Nafion-Bismuth Modified Glassy Carbon Electrodes

Abstract

In this work, a new method for the simultaneous determination of Pb(II) and Cd(II) on the multiwalled carbon nanotubes (MWNT)-Nafion-bismuth modified glassy carbon electrode (GCE) using square-wave anodic stripping voltammetry has been studied. Scanning electron microscopy was used to investigate the characteristics of the MWNT-Nafion-bismuth modified GCE. Well-defined sharp stripping peaks were observed in the determination of Pb(II) and Cd(II) simultaneously on this electrode. Under optimized conditions, the lowest detectable concentrations were 50 ng/l for Pb(II) and 80 ng/l for Cd(II) under a 10 min preconcentration. The attractive performances of MWNT-Nafion-bismuth modified GCE demonstrated its application for a simple, rapid, and harmless determination of trace heavy metals.     

ICP-MS法测定高纯钛中痕量元素

建立了ICP-MS直接测定高纯钛中Be,V,Co,Ni,Ga,Mo,Nb,Cd,Sb,TI,Pb的分析方法,并对ICP-MS工作参数及条件进行了优化和选择.高纯钛用HF与HNO3溶解后加入Sc、Cs、Re内标,用ICP-MS直接检测.方法的检出限为0.03～0.1 ng/mL,测定下限为0.2～0.5 ng/mL,各元...     

Determination of cadmium and lead in high purity uranium compounds by flame atomic absorption spectrometry with on-line micro-column preconcentration by CL-7301 resin

An on-line solid phase micro-column extraction and determination system for trace Cd and Pb in nuclear fuel grade uranium compounds was established. The preconcentration of trace elements Cd and Pb from uranium compounds was achieved by adsorbing Cd and Pb on CL-7301 resin in hydroiodic acid media, while the uranyl ion passed through. The method coupled with flame atomic absorption spectrometry (FAAS) was applied to analysis trace Cd and Pb in real samples. The preconcentration factors obtained by this method were 320 and 180 each for Cd and Pb, respectively. Under the optimized conditions, the detection limits corresponding to three times the standard deviation of the blank were found to be 0.13 ng·mL⁻¹ and 0.37 ng·mL⁻¹ for Cd and Pb, respectively. The relative standard deviation (RSD) and the recoveries of standard addition (spiked with 1–5 ng of Cd and Pb) were of <5% (n = 10) and 96.2%–102.3%, respectively. Precision was also evaluated and found to be ≤4.3% (N = 11). The proposed method was successfully used for the determination of trace Cd and Pb in commercially available uranium compounds (e.g., uranyl acetate and triuranium octoxide).     

Simultaneous Determination of Aluminum,Cadmium and Lead in Whole Blood by Simultaneous Atomic Absorption Spectrometry with Oxygen Charring

A method for the simultaneous determination of aluminum (Al), cadmium (Cd) and lead (Pb) in whole blood has been developed by using simultaneous atomic absorption spectrometry (SIMAAS) with oxygen charring. The optimized conditions for the simultaneous determination of Al, Cd and Pb were obtained in the presence of palladium (Pd) as the chemical modifier, using 600 °C and 2400 °C as the pyrolysis and the atomization temperature, respectively. The whole blood samples were diluted 1+5 (v/v) directly with 0.1% (v/v) Triton X‐100. Oxygen was employed to eliminate the interference of carbonaceous residues in the charring step before pyrolysis. The calibration curves were carried out with aqueous standard solutions and the linear ranges were 0–40 ng mL⁻¹, 0–4 ng mL⁻¹ and 0–40 ng mL⁻¹ for Al, Cd and Pb, respectively. The detection limits were 0.96 ng mL⁻¹ (19.2 pg) for Al, 0.03 ng mL⁻¹ (0.6 pg) for Cd and 0.60 ng mL⁻¹ (12.0 pg) for Pb. The spiked recoveries of Al, Cd and Pb in whole blood were 98.0%, 100.0% and 101.7%, respectively. The accuracy of the proposed method was evaluated with the analysis of a whole blood certified reference material (Seronorm, level 2). The found concentrations were in agreement with the recommended values. The proposed method has been successfully applied to the simultaneous determination of Al, Cd and Pb in whole blood of healthy volunteers before and after eating barbecued foods.     

Direct inductively coupled plasma-atomic emission spectrometry analysis of trace elements in muscle tissues of hairtail using electrothermal vaporization with slurry sampling

A procedure for direct determination of trace elements in muscle tissue of hairtail was developed using inductively coupled plasma-atomic emission spectrometry and electrothermal vaporization with slurry sampling. Due to use of polytetrafluoroethylene as the chemical modifier, the vaporization behaviors of analytes from the slurry and the aqueous standard solutions were very similar. In this case, the aqueous standards could be used for the calibration of slurry samples. The main factors influencing this method were studied systematically. The detection limits for Cr, Ni, Zn, Cd, and Pb were 3.1, 10.5, 176, 6.9, and 83 ng/mL, respectively, and the relative standard deviations were less than 10%. The proposed method was applied to the determination of trace Cr, Ni, Zn, Cd, and Pb in hairtail samples with satisfactory accuracy and precision. A certified reference material of mussel (GBW 08571) was analyzed, and good agreement was obtained between the results from the proposed method and certificate values.     

离子印迹壳聚糖/凹土分离富集-火焰原子吸收光谱测定中药材中痕量Cd(Ⅱ)的研究

建立了离子印迹壳聚糖/凹凸棒石(IICA)分离富集-火焰原子吸收光谱(FAAS)测定中药材中痕量Cd(Ⅱ)的新方法。在动态吸附条件下,系统研究了溶液pH值、流速、洗脱条件和干扰离子对痕量Cd(Ⅱ)分离富集的影响。研究表明,在pH为4.5,上样流速为0.60mL/min条件下,Cd(Ⅱ)能被IICA定量富集;吸附的Cd(Ⅱ)可用1.0mol/L HCl-0.1mol/L甲基异丁酮的乙醇溶液,在流速为0.96mL/min条件下完全洗脱。优化条件下,IICA对Cd(Ⅱ)的动态吸附容量为56.45mg/g。线性范围为0.00097～1.28mg/L,r=0.9994,检出限(3σ,n=11)为0.97μg/L,相对标准偏差为1.32%(n=6,c=0.08mg/L),回收率在96.5%～106.4%之间。该方法操作简便,灵敏度和精密度高,可应用于实际中药材样品中痕量镉的测定。