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.

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.

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.

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.

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.

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.

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。

火焰原子吸收光谱法测定碲化铜中银

采用标准方法火试金重量法测定碲化铜中银时,操作繁琐、耗时长、检测效率低,不适用于冶炼企业大批量样品快速分析检测。实验使用盐酸+硝酸溶解试样,在20%盐酸介质中,采用空气-乙炔火焰,以328.1 nm作为测定波长,建立了火焰原子吸收光谱法测定碲化铜中银的方法。在最优实验条件下,银质量浓度为0.30~3.00μg/mL时,其与吸光度呈良好线性关系,相关系数为0.999。方法检出限为0.002μg/mL,定量检出限为0.007μg/mL。本方法测定结果的相对标准偏差为0.19%~1.0%,加标回收率为98%~103%,且与标准方法测定结果一致。2种方法不存在显著性差异,可用于冶炼企业快速分析大批量碲化铜中银。

原子吸收光谱法测定富含锡铜精矿中的银

探讨了富含锡铜精矿中银的测定方法。矿样采用盐酸、硝酸、氢氟酸、高氯酸分解,赶尽氟和破坏有机物后,氢溴酸去除锡的干扰,在盐酸介质中,使用原子吸收光谱法测定银,经试验验证,该方法的检出限为0.00147%,测定范围为(10~1000)g/t,相对标准偏差为0.74%~0.87%,回收率在97.47%~102.56%之间,结果稳定可靠。

全自动消解-火焰原子吸收法测定土壤中的铜、锌、铅、镍、铬

采用全自动消解仪对样品进行前处理消解,以火焰原子吸收分光度法测定土壤中铜、锌、铅、镍、铬5种重金属的含量。该方法前处理操作简单、快速,可用于大批量样品的消解,分析结果准确、可靠,适用于土壤样品中铜、锌、铅、镍、铬的测定。

快速消解-原子吸收光谱法测定土壤中镉、铜的含量

建立了一种快速消解-原子吸收光谱法测定土壤中镉和铜含量的方法。采用快速消解法消解土壤,用原子吸收光谱法测定镉和铜的含量。镉和铜的回收率分别为83.0%~90.0%、85.0%~93.7%,且测定6份标准物质,镉和铜的相对标准偏差分别为2.70%、1.26%。建立的快速消解-原子吸收光谱法测定土壤中镉、铜的检测方法准确、可靠,适用于土壤中镉和铜含量的检测。

火试金重量法金粒不黄的铜精矿中金量的测定

目前,铜精矿中的金量的测定,一般使用国家标准GB/T 3884.2-2012[2],该标准中金量的测定采用火试金重量法。但有些复杂的铜精矿使用GB/T 3884.2-2012[2]得到的金粒不黄且发黑,甚至有些金粒发黑还容易碎裂。此类铜精矿金量的测定,GB/T 3884.2-2012[2]不适用。本文通过改善实验条件,利用火试金富集原子吸收光谱法测定金量。该方法测定复杂铜精矿中的金量精密度RSD在3.25%~4.97%,加标回收率为98.10%~100.15%。

低品位复杂铜多金属矿石中各物相中铜含量检测方法研究

本文考察了低品位复杂铜多金属矿石在不同试验中不同浸出溶剂对铜含量的变化,逐步确定了硫酸铜相、自由氧化铜相、结合氧化铜相、自然铜、次生硫化铜相的浸出条件。通过样品测定,表明火焰原子吸收光谱法测定铜多金属矿石中各物相中铜含量,方法简单,干扰少,结果准确。测定范围:0.010%~5.00%。

石墨炉原子吸收光谱法测定固定污染源废气中铜、镍、镉的前处理研究

比较硝酸-盐酸、硝酸-高氯酸、硝酸-高氯酸-氢氟酸三种消解方式处理固定污染源废气采样滤筒,硝酸-高氯酸消解体系溶出滤筒的本底值低且空白加标回收率高。硝酸-高氯酸消解体系的最佳条件是加入1 mL高氯酸消解至近干。用此消解方式测得固定污染源废气中铜、镍、镉的检出限依次为0.025,0.25,0.002μg/m^(3),煤飞灰中重金属成分分析标准物质(总量)(RMU010)的测定值与认定值基本一致。平行测定某实际煤飞灰样品6次,测定值的相对标准偏差为3.1%~5.9%。

原子吸收法测定矿石中铜铅锌

文中采取酸溶试样制成母液,稀释后作试液,控制试液、混合工作标准溶液和试样空白三者的酸性保持一致,同步测量。结果表明,线性相关系数铜>0.999、铅和锌均是0.998,检出限为铜0.007μg/m L、铅0.033μg/m L、锌0.012μg/m L,加标回收率铜95.0%~99.5%、铅99.1%~107.0%、锌95.6%~101.3%。用国家标准样品、实验室留存样品试验,测定结果准确一致。

碘量法和火焰原子吸收法在测定硫铁矿低铜含量准确性的讨论

碘量法是测铜的经典方法,此方法测定范围较宽;对高含量(铜精矿)的测定尤为常用。但在测定硫铁矿低铜含量样品时,碘量法没有火焰原子吸收法测定准确。