用石墨原子化法测定铝阳极氧化电解着色膜中的铜、镍、锡

了解着色膜中铜、镍、锡的沉积情况,是研究铝阳极氧化电解着色机理的前提.采用硝酸与醋酸褪除着色膜,并将标准曲线法运用于石墨原子吸收分光光度的测定中,从而测定褪除液中的铜、镍、锡含量.所测曲线的线性相关系数分别为 0.999 5,0.999 2和0.995 1;测定试液的加标回收率范围为 93.0%～103.4%;测试结果的相对标准偏差范围为 0.44%～3.70%.试验表明,用硝酸与醋酸褪膜,不仅能有效地去除着色膜,而且还有利于石墨原子化,此法所测结果对铝阳极氧化电解着色的研究具有一定的参考价值.     

石墨炉原子吸收法测定洗涤剂中砷含量

建立了石墨炉原子吸收光谱法测定洗涤剂中砷含量的方法。采取硝酸及高氯酸法处理样品,加入基体改进剂硝酸镍,应用石墨炉原子吸收光谱法测定砷。结果表明,测定一次回归方程为Y=0.0012X+0.0009,相关系数r=0.9994。检出限为0.16 ug/L,回收率为92.9%～101.4%,相对标准偏差为1.42%～3.18%。该方法具有快速、准确、灵敏度高等优点,适用于洗涤剂中砷含量的检测。     

Determination of trace aluminum in biological and water samples by cloud point extraction preconcentration and graphite furnace atomic absorption spectrometry detection

A cloud point extraction (CPE) method for the preconcentration of trace aluminum prior to its determination by graphite furnace atomic absorption spectrometry (GFAAS) has been developed. The CPE method is based on the complex of Al(III) with 1-phenyl-3-methyl-4-benzoyl-5-pyrazolone (PMBP), and then entrapped in non-ionic surfactant Triton X-114. PMBP was used not only as chelating reagent in CPE preconcentration, but also as chemical modifier in GFAAS determination. The main factors affecting CPE efficiency, such as pH of sample solution, concentration of PMBP and Triton X-114, equilibration temperature and time, were investigated in detail. An enrichment factor of 37 was obtained for the preconcentration of Al(III) with 10 mL solution. Under the optimal conditions, the detection limit of this method for Al(III) is 0.09 ng mL(-1), and the relative standard deviation is 4.7% at 10 ng mL(-1) Al(III) level (n=7). The proposed method has been applied for determination of trace amount of aluminum in biological and water samples with satisfactory results.     

Speciation of chromium in water samples with cloud point extraction separation and preconcentration and determination by graphite furnace atomic absorption spectrometry

A novel method has been developed for the speciation of chromium in natural water samples based on cloud point extraction (CPE) separation and preconcentration, and determination by graphite furnace atomic absorption spectrometry (GFAAS). In this method, Cr(III) reacts with 1-phenyl-3-methyl-4-benzoylpyrazol-5-one (PMBP) yielding a hydrophobic complex, which then is entrapped in the surfactant-rich phase, whereas Cr(VI) remained in aqueous phase. Thus, separation of Cr(III) and Cr(VI) could be realized. Total chromium was determined after the reduction of Cr(VI) to Cr(III) by using ascorbic acid as reducing reagent. PMBP was used not only as chelating reagent in CPE procedure, but also as chemical modifier in GFAAS determination of chromium. The detection limit for Cr(III) was 21 ng L(-1) with an enrichment factor of 42, and the relative standard deviation was 3.5% (n=7, c=10 ng mL(-1)). The proposed method has been applied to the speciation of chromium in natural water samples with satisfactory results.     

Solidified floating organic drop microextraction (SFODME) for simultaneous separation/preconcentration and determination of cobalt and nickel by graphite furnace atomic absorption spectrometry (GFAAS)

Solidified floating organic drop microextraction (SFODME), combined with graphite furnace atomic absorption spectrometry (GFAAS) was proposed for simultaneous separation/enrichment and determination of trace amounts of nickel and cobalt in surface waters and sea water. 1-(2-Pyridylazo)-2-naphthol (PAN) was used as chelating agent. The main parameters affecting the performance of SFODME, such as pH, concentration of PAN, extraction time, stirring rate, extraction temperature, sample volume and nature of the solvent were optimized. Under the optimum experimental conditions, a good relative standard deviation for six determination of 20 ng l⁻¹ of Co(II) and Ni(II) were 4.6 and 3.6%, respectively. An enrichment factor of 502 and 497 and detection limits of 0.4 and 0.3 ng l⁻¹ for cobalt and nickel were obtained, respectively. The procedure was applied to tap water, well water, river water and sea water, and accuracy was assessed through the analysis of certified reference water or recovery experiments.     

Speciation and determination of ultra trace amounts of chromium by solidified floating organic drop microextraction (SFODME) and graphite furnace atomic absorption spectrometry

Solidified floating organic drop microextraction (SFODME) method in combination with graphite furnace atomic absorption spectrometry (GFAAS) has been used for the determination of chromium species in water and urine samples. 1-undecanol containing 2-thenoyltrifluoroacetone (TTA) was used as a selective chelating agent for the extraction of Cr(III). The total Cr was determined after the reduction of Cr(VI) to Cr(III) with hydroxylamine. The concentration of Cr(VI) was determined from the difference between the concentration of total chromium and the Cr(III). Several variables such as the sample pH, concentration of TTA, salt concentration, extraction time and the sample volume were investigated in detail. Under the optimum conditions, the limit of detection of the proposed method was 0.006 μg l(-1) for Cr(III) and the relative standard deviation for six replicate determinations at 0.1 μg l(-1) Cr(III) was 5.1%. The proposed method was successfully applied for the determination of chromium species in tap water, well water, mineral water, and urine samples.     

Determination of trace lead in water samples by continuous flow microextraction combined with graphite furnace atomic absorption spectrometry

A new method of continuous flow microextraction (CFME) combined with graphite furnace atomic absorption spectrometry (GFAAS) was proposed for the determination of trace lead in water samples. A drop of 1-phenyl-3-methyl-4-benzoyl-5-pyrazolone (PMBP) dissolved in benzene is injected into a glass chamber by a microsyringe and held at the outlet tip of a PTFE connecting tube, the sample solution flows right through the tube and the glass chamber, the solvent drop interacts continuously with the sample solution, and the analyte was extracted into the drop and concentrated. After extracting for a period of time, the drop was retracted into the microsyringe and directly injected into graphite furnace for determination of Pb. Several factors affecting the extraction efficiency, such as solution pH, sample flow rate, drop volume and extraction time, were optimized. Under the optimized conditions, a concentration factor of 45 was achieved, and the detection limits for Pb were 12 pg mL(-1). The relative standard deviation for six replicate analyses of 10 ng mL(-1) Pb was 6.8%. The proposed method was applied to determine of trace Pb in water samples with satisfactory results.     

Determination of trace nickel in water samples by cloud point extraction preconcentration coupled with graphite furnace atomic absorption spectrometry

A new method based on the cloud point extraction (CPE) preconcentration and graphite furnace atomic absorption spectrometry (GFAAS) detection was proposed for the determination of trace nickel in water samples. When the micelle solution temperature is higher than the cloud point of surfactant p-octylpolyethyleneglycolphenyether (Triton X-100), the complex of Ni2+ with 1-phenyl-3-methyl-4-benzoyl-5-pyrazolone (PMBP) could enter surfactant-rich phase and be concentrated, then determined by GFAAS. The main factors affecting the cloud point extraction were investigated in detail. An enrichment factor of 27 was obtained for the preconcentration of Ni2+ with 10 mL solution. Under the optimal conditions, the detection limit of Ni2+ is 0.12 ng mL(-1) with R.S.D. of 4.3% (n = 10, c = 100 ng mL(-1)). The proposed method was applied to determination of trace nickel in water samples with satisfactory results.     

基于不确定度评价对稻米中镉元素分析标准物质高精度定值方法的比较

通过对稻米中镉含量测定的3种典型方法(石墨炉原子吸收光谱法(GFAAS)、电感耦合等离子体质谱法(ICP-MS)和同位素稀释电感耦合等离子体质谱法(ID-ICP-MS))测量不确定度分量来源、类型、贡献进行系统分析比较,为稻米镉分析标准物质高精度定值方法的选择和定值的过程控制提供依据.研究结果显示,GFAAS、ICP-...     

Determination of aluminum in the human serum of a dialysis patient by ion-pair reversed-phase partition high-performance liquid chromatography.

An ion-pair reversed-phase partition high-performance liquid chromatography-spectrophotometric method is described for the determination of aluminum in human serum, based on its complexation with 2,2'-dihydroxyazobenzene. The chelate is separated on C18-bonded silica packing by using an aqueous methanol mobile phase containing tetrabutylammonium bromide and is detected with 0.005 AU full-scale at 510 nm. The proposed system offers a simple, sensitive, and selective method. The detection limits defined as twice the standard deviation of the blank signal, are 0.2 micrograms L-1 in pure solution and 6 micrograms L-1 in serum. The sample solution is prepared from 0.4 mL of serum after protein precipitation with hydrochloric acid and methanol. There was good agreement between the values obtained by this method and graphite furnace atomic absorption spectrophotometry. The aluminum concentrations in 121 patients on hemodialysis were 6-201 micrograms L-1.     

石墨炉原子吸收光谱法直接测定纺织品萃取汗液中砷

本文采用石墨炉原子吸收光谱法直接测定纺织品萃取液中砷。通过在样品萃取液中加入基体改进剂,并对石墨炉原子化工作条件和基体改进剂用量进行优化。结果表明,加入4μL 50g/L硝酸镍基体改进剂,可以有效降低高浓度氯化钠基体的影响,样品检出限可达到0.05mg/kg,相对标准偏差为为1.65~3.44%,实际纺织品样品加标回收率为93.8%~103%。该方法具有快速、准确、灵敏度高等优点,适用于测定纺织品萃取汗液中砷含量的检测。     

ICP-AES法测定斑岩型铜矿石中铜铅锌钼

本文用ICP-AES法测定斑岩型铜矿中的铜铅锌钼。采用盐酸硝酸氢氟酸和高氯酸四种酸混合消化样品。研究仪器的最佳工作参数,用基体一致时测定待测元素来校正基体干扰,分别找出仪器测定的最佳分析谱线进行样品测量。本方法的检出限在0.21?g/g～0.65?g/g。测量结果的相对标准偏差为0.36%～1.8%(n=8),回收率在95%-102.6%之间。     

JY Ultima2ICP-OES光谱仪测定Ta-2.5W和Ta-10W中钨元素的分析方法研究

采用发射光谱仪建立发射光谱法测定Ta-2.5W和Ta-10W中钨含量的方法。使用高纯氢氧化钽基体的纯钨标准溶液制作工作曲线,钨的分析线为209.475 nm,方法的线性范围为1.25%~15.00%,加标回收率在93.0%~99.0%之间,测定结果的RSD值(n=11)小于0.8%。     

Study on solid phase extraction and graphite furnace atomic absorption spectrometry for the determination of nickel, silver, cobalt, copper, cadmium and lead with MCI GEL CHP 20Y as sorbent

A solid phase extraction and graphite furnace atomic absorption spectrometry (GFAAS) for the determination of nickel, silver, cobalt, copper, cadmium and lead with MCI GEL CHP 20Y as sorbent was studied. Trace amounts of chromium, nickel, silver, cobalt, copper, cadmium and lead were reacted with 2-(2-quinolinil-azo)-4-methyl-1,3-dihydroxidobenzene (QAMDHB) followed by adsorption onto MCI GEL CHP 20Y solid phase extraction column, and 1.0molL(-1) HNO(3) was used as eluent. The metal ions in 300mL solution can be concentrated to 1.0mL, representing an enrichment factor of 300 was achieved. The recoveries of analytes at pH 8.0 with 1.0g of resin were greater than 95% without interference from alkaline, earth alkaline and some metal ions. When detected with graphite furnace atomic absorption spectrometry, the detection limits in the original samples were 1.4ngL(-1) for Cr(III), 1.0ngL(-1) for Ni(II), 0.85ngL(-1) for Ag(I), 1.2ngL(-1) for Co(II), 1.0ngL(-1) for Cu(II), 1.2ngL(-1) for Cd(II) and 1.3ngL(-1) for Pb(II). The validation of the procedure was performed by the analysis of the certified standard reference materials, and the presented procedure was applied to the determination of analytes in biological, water and soil samples with good results (recoveries range from 89 to 104%, and R.S.D.% lower than 3.2%. The results agreed with the standard value or reference method).     

原子吸收光谱法测定光学新材料钛酸钡锶中锶的研究

本文介绍火焰原子吸收光谱法测定光学新材料钛酸钡锶中锶的方法,研究样品制备和测试条件,消除共存元素干扰。本法的回收率为99～101％,相对标准偏差为0.72％。     

电感耦合等离子体原子发射光谱法测定电解钴中杂质元素

金属钴试样经酸消解后,未经基体分离直接以全谱直读电感耦合等离子发射光谱仪测定其中杂质元素。确定了仪器的最佳工作条件,选择了合适的分析谱线,采用钇作为内标物质,补偿基体效应。方法测定各元素的检出限在0.0001～0.02mg.L-1范围内。方法用于样品的测定,相对标准偏差为1.5%～7.5%,回收率为94.0～104.0%,各元素的测定值与国家标准方法的测定值相符合。     

Determination of trace lead in water samples by graphite furnace atomic absorption spectrometry after preconcentration with nanometer titanium dioxide immobilized on silica gel

Nanometer titanium dioxide immobilized on silica gel (immobilized nanometer TiO2) was prepared by sol-gel method and characterized using X-ray diffraction (XRD) and scanning electron microscope (SEM). The adsorptive capability of immobilized nanometer TiO2 for lead was assessed in this work using column method. It was found that lead can be quantitatively retained by immobilized nanometer TiO2 in the pH range 4-7, then eluted completely with 1.0molL(-1) HCl. The adsorption capacity of immobilized nanometer TiO2 for Pb was found to be 3.16mgg(-1). A new method has been developed for the determination of trace lead based on preconcentration with a microcolumn packed with immobilized nanometer TiO2 prior to its determination by graphite furnace atomic absorption spectrometry (GFAAS). The detection limit of this method for Pb was 9.5ngL(-1) with an enrichment factor of 50, and the relative standard deviations (R.S.D.s) was 3.2% at the 10ngmL(-1) Pb level. The method was validated using a certified reference material, and was applied for the determination of trace lead in water samples.     

石墨炉原子吸收光谱法测定超高纯试剂中钙的研究．

研究了超高纯试剂异丙醇中痕量钙的石墨炉原子吸收光谱测定法。制定了石墨炉原子吸收光谱法测定痕量钙的分析程序，试样经挥发浓缩，采用标准曲线法测定；还确定了仪器最佳工作条件，原子化条件等，研究了共存离子的干扰，回收试验及实测样品等。同时将石墨管用氯氧化锆进行适当的处理，并控制合适的仪器操作条件及升温程序，即可提高石墨炉原子吸收法测钙的灵敏度，获得了较满意的结果。     

工业盐酸中微量氟的测定

样品分离氯离子后,在弱酸性介质中,用氟离子选择性电极、已知量添加法测定工业盐酸中微量氟。本方法标准偏差为5×10~(-5)％,变异系数<6％。回收率在91.8～104.0％。方法简便、数据准确。     

Crystal structure and optical properties of oxynitride rare-earth tantalates RTa-(O, N) (R = Nd, Gd, Y)

X-ray absorption and photoluminescence were used to investigate the structure of rare-earth tantalum oxynitrides RTa-(O, N) (R = Nd, Gd, Y). Owing to the size of the rare-earth element, the crystal structure tends towards the pyrochlore or defect fluorite-type structure. EXAFS suggested neodymium and yttrium atoms are coordinated either by 6 + 2 or 6 oxygen/nitrogen atoms in the Nd or Y respective oxynitrides although the coordination number of tantalum is six in both compounds. Photoluminescence for 5 at.% doped europium showed the spectra compatible with the point symmetry C_3v lower than O_h in fluorite and D_3d in pyrochlore structure type for both the Gd and Y tantalum oxynitrides. These measurements supported that their structure types were basically pyrochlore for Nd and Gd tantalum oxynitrides and defect fluorite for Y tantalum oxynitride but they are highly defective.