Determination of Ultratrace Amounts of Copper(Ⅱ) in Water Samples by Electrothermal Atomic Absorption Spectrometry After Cloud Point Extraction

A novel approach was developed for the determination of ultratrace amounts of copper in water samples by using electrothermal atomic absorption spectrometry （ETAAS） after cloud point extraction （ CPE ）. 1-（ 2-Pyridylazo ） -2- naphthol was used as the chelating reagent and Triton X-114 as the mieellar-forming surfactant. CPE was conducted in a pH 8. 0 medium at 40 ℃ for 10 rain. After the separation of the phases by contrifugafion, the surfactant-rieh phase was diluted with 1 mL of a methanol solution of 0. 1 mol/L HNO3. Then 20μL of the diluted surfactant-rieh phase was injected into the graphite furnace for atomization in the absence of any matrix modifier. Various experimental conditions that affect the extraction and atomization processes were optimized. A detection limit of 5 ng/L was obtained after preconeentration. The linear dynamic range of the copper mass concentration was found to be 0-2.0 ng/mL, and the relative standard deviation was found to be less than 3. 1% for a sample containing 1.0 ng/mL Cu （ Ⅱ ）. This developed method was successfully applied to the determination of uhratraee amounts of Cu in drinking water, tap water, and seawater samples.

Flow Injection Semi-online Preconcentration Graphite Furnace Atomic Absorption Spectrometry for Determination of Cadmium,Copper and Manganese

A micro-flow injection sorbent extraction preconcentration system was combined with a graphite furnace atomic absorption spectrometry that formed an integrated system for the determination of trace amounts of elements. The analytical performances of the prospsed method for determining Cd, Cu and Mn were studied. The analytes were preconcentrated with a thiol resin(Type 190, produced by Nankai University, China) whose active group is -SH. The elements to be determined were preconcentrated onto the column for 60 s and then rinsed with deionized water and eluted with 30 μL of 1 mol/L HCl. The graphite furnace atomic absorption spectrometry(GFAAS) determination of the concentrated analyte was carried out in parallel with the next preconcentration cycle. Enrichment factors 41, 22 and 20 and detection limits(3 σ , n =10) 0.36, 3.8 and 7.0 ng/L for Cd, Cu and Mn, respectively, along with a sampling frequency of 20 h -1 , were obtained with a 60 s loading time at a sample flow rate of 3.5 mL/min. The analytical results for a number of water samples show that the flow-injection semi-online column preconcentration can not only eliminate the effect of some concomitant elements, such as Li, Na, K, Ca and Mg, on the determination of the analyte, but also enhance the sensitivity.

Uncertainty in Detecting Copper and Zinc Contents in Maize Flour by Flame Atomic Absorption Spectrometry with Wet Digestion Method

[ Objective] This study aimed to evaluate the uncertainty in detecting copper and zinc contents in maize flour by flame atomic absorption spectrometry. [ Method] Combined with the actual inspection experience, the uncertainty in detecting copper and zinc contents in maize flour by tame atomic absorption spec- trometry was evaluated to establish the mathematical model. The uncertainty sources in the experimental process were investigated to analyze several components af- fecting the uncertainty in sample detection, including sample weighing, standard material transfer, solution dilution and volume setting, curve fitting, and repeat- ability of measurement instruments. [ Result] Standard curve fitting and repeatability test were two major factors that significantly affected the combined standard uncertainty. However, in the actual detection process, standard curve calibration and repeated detection procedures should be controlled strictly. Finally, the ex- panded uncertainty of copper and zinc contents in maize flour was （ 1.38 ± 0.08） mg/kg and （ 10.20 ± 1.20） mg/kg, respectively. [ Conclusion] This study provided reference for improving the accuracy and reliability of the detection method.

Separation/Enrichment of Copper and Silver Using Titanium Dioxide Nanoparticles Coated with Poly-Thiophene and Their Analysis by Flame Atomic Absorption Spectrophotometry

We report on the use of titanium dioxide nanoparticles (NPs) coated with poly-thiophene for the preconcentration of copper and silverions. The NPs were prepared by first modifying the surface of TiO2 NPs with vinyl groups and then copolymerizing them with vinyl thiophen. The resulting TiO2-polythiophene core-shell NPs were characterized by thermogravimetry, differential thermal analysis, scanning electron microscopy, Fourier transform infrared spectrometry and X-ray diffraction. The experimental conditions such as pH value, adsorption and desorption time, type, concentration and volume of the eluent, break through volume, and effect of potentially interfering ions were optimized. The ions were then desorbed with hydrochloric acid and determined by FAAS. The limits of detection are 0.4 and 1.2 μg·L_1 for Cu(II) and Ag(I), respectively, and recoveries and precisions are >98.0%

Determination of Copper and Lead Contents in Soil of the Yellow River Wetland in Shaanxi Province by Flame Atomic Absorption Spectrometry

[Objectives] The contents of copper and lead in the soil of the Yellow River Wetland were determined by flame atomic absorption spectrometry, which provides a theoretical basis for the treatment of soil pollution. [Methods] The soil was digested with a concentrated nitric acid-hydrofluoric acid-perchloric acid system, and the contents of heavy metals such as copper and lead in the Yellow River Wetland of Shaanxi Province were determined by flame atomic absorption spectrometry. [Results] The correlation coefficients reached 0.999 5 in the range of 0.00-1.00 mg/L, indicating good linearity. [Conclusions] The method is simple in operation, good in reproducibility, high in sensitivity to most elements, and can be widely used.

FLAME ATOMIC ABSORPTION DETERMINATION OF COPPER IN CEREALS FOOD SAMPLES WITH THE PRECONCENTRATION OF POTASSIUM TETRATITANATE WHISKER

A simple and reliable method has been developed for separation and preconcentration of trace amounts of copper ions in cereals food for subsequent measurement by flame atomic absorption spectrometry (FAAS). The Cu2+ ions are adsorbed selectively and quantitatively during the passage. The retained copper ions were desorbed from the potassium tetratitanate whisker with 10.0mL of 2mol/L sulphuric acid solutions as eluent and were determined by FAAS. The linear range was 0.05μg/mL^0.20μg/mL in the original solution with a correlation coefficient of 0.9998. The detection limit of the proposed method is 2.1ng/mL in the original solution (3σ, n=9). Determination of copper in standard ions showed that the proposed method has good accuracy (recovery was more than 95%). The method was successfully applied for recovery and determination of copper in cereals food samples.

Releasing of Cupric Ion of Three types of Copper-bearing Intrauterine Contraceptive Device in Simulated UterineFluid

Objective To compare the cupric ion releasing in vitro o.f the three IUDs. Methods The stability o.f cupric ion releasing o.f IUDs including TCu 380.4 IUD （TCu 380A）, Multiload Cu375 IUD （MCu 375） and Yuangong 365 copper-bearing indomethacin-releasing IUD （Yuangong 365） by the determination of cupric ion releasing in simulated uterine fluid. The simulated uterine fluid was used for releasing media. Copper ion was determined by flame atomic absorption spectrometer. Results The cupric ion releasing of three IUDs were instable at the beginning and tend to be stable gradually. In the stable phase, the average level of cupric ion releasing of TCu380A, MCu375 and Yuangong 365 were 4.25±2.71-7.62±6.42 μg, 4.92±1.23 -8.62±3.08 μg and 2.19±0.40-4.68±1.66 μg, respectively. TCu380A had higher instable releasing level than those of Yuangong 365 （P〈0. 05）. Conclusion TCu 380.4 and MCu 375 showed a ＂burst release＂ during the first few days and the.former was of great significance（P〈0.05）. The initial cupric ion releasing of Yuangong 365 appeared to be the lowest, followed by MCu375 and TCu380A in a releasing order

Contamination of copper in leafy vegetables grown near Kalyan Railway Track, Maharashtra, India

Background:Majority of human population is suffering from vitamins and mineral deficiencies.Leafy vegetables are used to overcome this problem.Heavy metal contaminations of vegetables cannot be underestimated as these are important components for diet.In Mumbai almost all the farms are closer to railway tracks along the harbour,central and western railways;local farmers in the absence of proper irrigation facilities use water from the drains to grow their crops.This Untreated sewage water increases heavy metals in soil and crops along with pathogens.Utilization of sewage water containing heavy metals due to small scale industries in urban areas deserves special attention as it makes environment quite unsuitable for human and animal health and growth of plants.Copper is essential element while in excess it can cause many diseases.Methods:The present study is undertaken with an aim to study presence of heavy metal i.e.copper in the vegetables,water and soil alongwith physico-chemical parameters.Atomic absorption spectrophotometer was used to determine copper content in vegetable samples like Spinacia oleracea and Amaranthus caudatus.Results:The level of copper present in the vegetable was found to be higher than the permissible limits with water being the major cause of excessive copper contamination.The physicochemical parameters were found to be exceeding the drinking water and irrigation standards.Conclusion:The irrigation water is the major source of copper which increases the copper content higher than the permissible limits.But more sampling and research is essential to understand the ingress of heavy metals in the leafy vegetables.

A novel method for the determination of trace copper in cereals by dispersive liquid-liquid microextraction based on solidification of floating organic drop coupled with flame atomic absorption spectrometry

A novel,simple,rapid,efficient and environment-friendly method for the determination of trace copper in cereal samples was developed by using dispersive liquid-liquid microextraction based on solidification of floating organic drop（DLLME-SFO） followed by flame atomic absorption spectrometry.In the DLLME-SFO,copper was complexed with 8-hydroxy quinoline and extracted into a small volume of 1-dodecanol,which is of low density,low toxicity and proper melting point near room temperature. The experimental parameters affecting the extraction efficiency were investigated and optimized.Under the optimum conditions, the calibration graph exhibited linearity over the range of 0.5—500 ng/mL with the correlation coefficient（r） of 0.9996.The enrichment factor was 122 and the limit of detection was 0.1 ng/mL.The method was applied to the determination of copper in the complex matrix samples such as rice and millet with the recoveries for the spiked samples at 5.0 and 10.0 u,g/g falling in the range of 92.0-98.0%and the relative standard deviation of 3.9-5.7%.

Determination of Copper by Flame Atomic Absorption Spectrometry after Preconcentration with Activated Carbon Impregnated with a New Schiff Base

A simple and reliable method for the extraction and determination of trace amounts of copper（Ⅱ） ions using activated carbon （AC） impregnated by a new Schiff base 5-[（4-heptyloxyphenyl）azo]-N-（4-propyloxyphenyl）-salicylaldimine （HPPS） and atomic absorption spectrometry is presented. Recovery efficiency and the influence of pH value, volume of sample solution, effect of different eluents, and interfering ions were evaluated. The limit of detection （3σ） was 2.62 ng.mL^-1 and the relative standard deviation （n=10） was 1.5%. Under optimum conditions, the copper ions were concentrated 25 fold using 250 mL of sample solution and 10 mL of eluent. This procedure has been successfully applied to the determination of copper in different water samples.

Preconcentration and Determination of Copper（Ⅱ） Using Octadecyl Silica Membrane Disks Modified by 1,5-Diphenylcarhazide and Flame Atomic Absorption Spectrometry

A simple and reproducible method for the rapid extraction and determination of trace amounts of copper（Ⅱ） ions using octadecyl-bonded silica membrane disks modified by 1,5-diphenylcarbazide （DPC） and atomic absorption spectrometry was presented, which was based on complex formation on the surface of the ENVI-18 DISK^TM disks followed by stripping of the retained species by minimum amounts of appropriate organic solvents. The elution was efficient and quantitative. The effect of potential interfering ions, pH, ligand amount, stripping solvent, and sample flow rate were also investigated. Under the optimal experimental conditions, the break-through volume was found to be about 1000 mL providing a preconcentration factor of 400. The maximum capacity of the disks was found to be （255±5） lag for Cu^2＋, and the limit of detection of the proposed method was 5 ng per 1000 mL. The method was applied to the extraction and recovery of copper in different water samples.

火焰原子吸收光谱法测定配合饲料中铜、铁和锰含量的不确定度评定

研究旨在建立火焰原子吸收光谱法测定配合饲料中铜、铁和锰含量的不确定度评定方法,真实反映测量的置信度和准确性。首先分析测定过程中的不确定度来源,对不确定度分量进行量化,然后通过数学模型计算出饲料中铜、铁和锰含量,合成扩展不确定度。结果显示:饲料中铜、铁和锰的含量分别为(11±2)、(214±10)、(92±4)mg/kg,不确定度为扩展不确定度,包含因子为2,对应的置信水平是95%。本研究发现样品消解、样品溶液浓度测定和含量重复性测量是影响饲料中铜、铁、锰含量测量中不确定度的主要因素,应特别关注样品的前处理过程、标准工作液的配制,并使待测样品的浓度落在曲线的中间位置,以提高检测准确性。

火焰原子吸收光谱法测定岩石样品中铜、铅、锌的研究

主要研究火焰原子吸收光谱法测定岩石样品中的铜、铅、锌。采用石墨消解仪和HF-HCl-HNO3-HClO4酸系消解样品的前处理方法效果相对较好,酸性介质可用盐酸或硝酸溶液,浓度宜为2%~5%。通过实验得出:铜、铅、锌的检出限分别为0.012μg/mL、0.057μg/mL、0.009μg/mL,测定下限分别为0.048μg/mL、0.228μg/mL、0.036μg/mL,方法RSD值(精密度)1.0%~3.6%,加标回收率97.29%~101.0%,符合岩石矿物分析规范的要求。火焰原子吸收光谱法测定铜、铅、锌具有操作简便、实验用时短、干扰少及较好的准确度和精密度的特点。

地质样品银、铜、铅、锌测定过程中应用试液称重火焰原子吸收分光光度法的研究

本文应用试液称重火焰原子吸收分光光度法对地质样品银、铜、铅、锌元素进行测定。通过试验发现该方法不仅操作起来非常简便,而且测试速度快,所用试剂较少,试验操作不会对人员和环境造成伤害。另外,这一方法通过国家标准物质测定验证,获得的结果能够满足地质规范相关要求,在地质样品大批量测定过程当中可以推广应用。

Solid Phase Extraction of Trace Copper（Ⅱ） Using Octadecyl Silica Membrane Disks Modified with N,N′-Disalicylideneethylenediamine

A simple and reproducible method for the rapid extraction and determination of trace amounts of copper（Ⅱ） ions using octadecyl-bonded silica membrane disks modified by N,N′-disalicylideneethylenediamine （DESDA） and atomic absorption spectrometry was presented. The method is based on complex formation on the surface of the ENVI-18 DISK^TM disks followed by stripping of the retained species by minimum amounts of appropriate organic solvents. The elution is efficient and quantitative. The effects of potential interfering ions, pH, ligand amount, stripping solvent, and sample flow rate were also investigated. Under the optimal experimental conditions, the break-through volume was found to about be 1000 mL providing a preconcentration factor of 500. The maximum capacity of the disks was found to be （389±4） μg for Cu^2＋. The limit of detection of the proposed method is 5 ng per liter. The method was applied to the extraction and recovery of copper in different water samples.

Ultrasound-assisted emulsification solidified floating organic drop microextraction for the determination of trace amounts of copper in water samples

A simple and efficient liquid-phase microextraction(LPME)technique was developed using ultrasound-assisted emulsification solidified floating organic drop microextraction(USAE-SFODME)combined with flame atomic absorption spectrometry,for the extraction and determination of trace copper in water samples.1-(2-Pyridylazo)-2-naphthol(PAN)was used as chelating agent.Microextraction efficiency factors(including extraction solvent type,extraction volume,time,temperature,and pH),the amount of the chelating agent,and salt effect were investigated and optimized.Under the optimum extraction conditions,figures of merit of the proposed method were evaluated.The calibration graph was linear in the range of 20–600 mg·L^(–1)with a detection limit of 0.76 mg·L^(–1).The relative standard deviation(R.S.D)for ten replicate measurements of 20 and 400 mg·L^(–1)of copper was 3.83%and 2.65%,respectively.Finally,the proposed method was applied to tap water,river water,and sea water,and accuracy was assessed through the analysis of certified reference water or recovery experiments.

基于原子吸收法的土壤中金属镉、铜的检测技术研究

为解决传统湿法消解测量土壤中金属镉、铜测量周期长、一致性差的不足,提出了一种新的基于原子吸收法的土壤中金属镉、铜快速测量技术。该技术首先采用快速消解法对土壤进行消解处理,然后再利用原子吸收法对土壤中金属镉、铜的含量进行测定。实际应用表明,新的测试技术对金属镉的测定偏差在1.89%以内,对金属铜的测试偏差在1.6%以内,新测试技术的测试时间比湿法消解测试降低了56.25%,实现了对土壤中金属镉、铜元素的快速、精确测定。

FAAS测定铅矿石中铜含量的不确定度评定

本研究采用FASS检测技术,根据GB/T14353.1-2010的实验标准方法对铅矿石中铜元素的含量进行测定。然而实验测量过程中会产生不可避免的不确定度,因此对实验过程中产生的不确定度进行评定,结果表明测量铅矿石样品中铜的含量为284±27.49μg/g,确定了实验过程中产生不确定度的主要来源,包括样品重复性测量、样品称量、样品体积定容、标准曲线拟合及标准溶液的配制,对比发现标准曲线拟合的不确定度对测量结果的影响最大。

火焰原子吸收光谱法测定鼓风炉铜熔炼水淬渣中铜的含量

试样在高温马弗炉中过氧化钠熔融,经盐酸浸取,于原子吸收分光光度计波长324.7 nm处测量其吸光度。干扰试验表明,样品中的其他共存元素均不干扰测定,铜的质量浓度在0.50~10.00μg/mL范围内与其对应的吸光度呈线性关系,相关系数为0.9995,方法检出限为0.029μg/mL,定量限为0.097μg/mL。采用试验方法对鼓风炉铜熔炼过程中的水淬渣铜含量进行测定,结果表明铜含量的测定结果与电感耦合等离子体原子发射光谱法(ICP-AES)基本一致,相对标准偏差(n=11)为0.49%~1.87%。

火焰原子吸收光谱法、石墨炉原子吸收光谱法和电感耦合等离子体发射光谱法测定地表水样中铜的研究方法对比

采用火焰原子吸收光谱法(FAAS)、石墨炉原子吸收光谱法(GF-AAS)和电感耦合等离子体发射光谱法(ICP-OES)分别测定地表水中的铜,对检出限、精密度、正确度、低浓度环境样品测试等指标进行对比。实验结果表明,三种方法对于测定地表水中铜,测试结果无显著差异;与FAAS和ICP-OES法相比,GF-AAS法具有较低的检出限、较高灵敏度,对于测定低浓度环境样品具有较高的准确性。