摘要：
A new method, which involves liquid-phase microextraction (LPME) followed by high performance liquid chromatography (HPLC) with diode array detector (DAD), was developed to determine phoxim in water sample. Experimental parameters affecting the extraction efficiency, such as extraction solvent, solvent volume, agitation speed of the sample and extraction time were investigated. Under the optimal extraction conditions, phoxim was found to yield a good linear calibration curve in the concentration range from 0.01 to 5 mu g mL(-1), The limit of detection (LOD) is 10 ng mL(-1), and relative standard deviation (RSD) at the 100 ng mL(-1) levels is 8.4%. Lake water and tap water samples were successfully analyzed using the proposed method. (c) 2004 Elsevier B.V. All rights reserved.
摘要：
Nanometer titanium dioxide immobilized on silica gel (immobilized nanometer TiO(2)) was prepared by sol-gel method and characterized by using X-ray diffraction (XRD) and scanning electron microscope (SEM). The adsorptive potential of immobilized nanometer TiO(2) for the preconcentration of trace Cd, Cr, Cu and Mn was assessed in this work. The metal ions studied can be quantitative retained at a pH range of 8-9, and 0.5molL(-1) HNO(3) was sufficient for complete elution. The adsorption capacity of immobilized nanometer TiO(2) for Cd, Cr, Cu and Mn was found to be 2.93, 2.11, 6.69 and 2.47mgg(-1), respectively. A new method using a microcolumn packed with immobilized nanometer TiO(2) as sorbent has been developed for the preconcentration of trace amounts of Cd, Cr, Cu and Mn prior to their determination by inductively coupled plasma atomic emission spectrometry (ICP-AES). The method has been successfully applied for the determination of trace elements in some environmental samples with satisfactory results.
期刊：
JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY,2004年19(8):1006-1009 ISSN：0267-9477
通讯作者：
Liang, P
作者机构：
[Liu, Y; Liang, P; Guo, L] Cent China Normal Univ, Coll Chem, Wuhan 430079, Peoples R China.
通讯机构：
[Liang, P] C;Cent China Normal Univ, Coll Chem, Wuhan 430079, Peoples R China.
摘要：
A sensitive and selective method has been developed for the determination of Mo in steel samples using a nanometre-sized titanium dioxide micro-column (20 mm × 3.0 mm id) and inductively coupled plasma atomic emission spectrometry (ICP-AES). Under the optimized conditions (pH 1.0, flow rate 1.5 mL min−1), Mo was retained on the column and separated from the iron matrix, then eluted with 0.5 mol L−1 NaOH and determined by ICP-AES. The adsorption capacity of nanometre TiO2 for Mo was found to be 2.01 mg g−1. The detection limit for Mo was 0.14 μg L−1, with an enrichment factor of 100, and the relative standard deviation (RSD) was 1.8% (n = 11, C = 50 μg L−1). The proposed method has been applied to the determination of Mo in certified reference steel samples with satisfactory results.
期刊：
JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY,2004年19(11):1489-1492 ISSN：0267-9477
通讯作者：
Liang, P
作者机构：
[Liu, Y; Lu, HB; Liang, P; Zeng, J; Guo, L] Cent China Normal Univ, Coll Chem, Wuhan 430079, Peoples R China.
通讯机构：
[Liang, P] C;Cent China Normal Univ, Coll Chem, Wuhan 430079, Peoples R China.
摘要：
The potential of multiwalled carbon nanotubes (MWNTs) as a solid-phase extraction adsorbent for the preconcentration of trace Cd, Mn and Ni has been investigated. The studied metal ions can be adsorbed quantitatively on MWNTs at pH 8.0, then eluted completely with 0.5 mol L<sup>-1</sup> HNO<inf>3</inf>. The adsorption capacity of MWNTs was found to be 7.42, 4.86 and 6.89 mg g <sup>-1</sup> for Cd, Mn and Ni, respectively. A new method using a microcolumn packed with MWNTs as sorbent has been developed for the preconcentration of trace amounts of Cd, Mn and Ni prior to their determination by inductively coupled plasma atomic emission spectrometry (ICP-AES). Parameters influencing the preconcentration of the analytes, such as pH of the sample, sample flow rate and volume, elution solution and interfering ions, have been examined. The method has been successfully applied to the determination of trace elements in some environmental samples with satisfactory results.
摘要：
A new method using nanoparticle TiO<inf>2</inf> as solid-phase extractant coupled with FAAS was proposed for preconcentration and determination of trace Zn and Cd. The effects of pH, contact time, elution solution and interfering ions on the adsorption behavior of nanometer TiO<inf>2</inf> towards Zn and Cd were investigated. Under optimum conditions, nanometer TiO<inf>2</inf> possesses a significant capacity for the sorption of the metal ions studied. The limits of detection (3δ) of this method were 1.8 ng mL<sup>-1</sup> of Zn and 3.0 ng mL<sup>-1</sup> of Cd with an enrichment factor of 12.5, and relative standard deviations were 3.8% and 4.3% for Zn and Cd, respectively (c = 0.5 μg mL<sup>-1</sup>, n = 9). The proposed method was validated by the analysis of water certified reference material.
摘要：
A new method is proposed for the determination of trace chromium and copper in water samples by inductively coupled plasma optical emission spectrometry after cloud point extraction (CPE). The method is based on the complexation of metal ions with 8-hydroxyquinoline in the presence of non-ionic micelles of Triton X-100. The effect of experimental conditions such as pH, concentration of chelating agent and surfactant, equilibration temperature and time on cloud point extraction was studied. Under the optimum conditions, the detection limits were 1.29 and 1.31 ng mL-1 for chromium and copper, respectively, with relative standard deviations of 4.3% and 4.8%, respectively (n= 11). The proposed method was applied to the determination of trace chromium and copper in water samples with satisfactory results.
摘要：
A sensitive and selective method has been developed for the speciation of Cr(III) and Cr(VI) in natural water using a nanometer titanium dioxide micro-column (20 mm×3.0 mm i.d.) and inductively coupled plasma atomic emission spectrometry (ICP-AES). Under the optimized conditions (pH 6.0, flow rate 1.0 ml min−1), Cr(III) was retained on the column, then eluted with 2.0 mol l−1 HCl and determined by ICP-AES. Total chromium was determined after the reduction of Cr(VI) to Cr(III) by ascorbic acid as reducing reagent. The adsorption capacity of nanometer TiO2 for Cr(III) was found to be 7.6 mg g−1. The detection limit for Cr(III) was 0.32 μg l−1 and the relative standard deviation (R.S.D.) was 2.4% (n=11, C=100 μg l−1) with an enrichment factor of 50. The proposed method has been applied to the determination and speciation of chromium in natural water samples with satisfactory results.
摘要：
浊点萃取法(Cloud Point Extration,CPE)[1,2]是近年来出现的一种新兴的环保型液-液萃取技术,它不使用挥发性的有机溶剂,不影响环境.它以表面活性剂胶束水溶液的溶解性和浊点现象为基础,通过改变实验参数如溶液pH值、温度等引发相分离,将疏水性物质与亲水性物质分离.它具有经济、安全、高教、简便等优点,已广泛用于生命科学、环境科学研究中[3].自Watanabe[4]等将其成功的用于金属离子的萃取后,引起了分析科学家们的极大关注与重视,并应用于金属离子的分离富集及形态分析[5].
