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

IntroductionIn environment, copper is usually found in traceor ultratrace levels, and its detection requires sensitiveinstrumental measuring techniques such as electrother-mal atomic absorption spectrometry(ETAAS) and ICP-AES or ICP-MS. Frequently, a prec…     

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 micellar-forming surfactant. CPE was conducted in a pH 8.0 medium at 40 ℃ for 10 min. After the separation of the phases by centrifugation, the surfactant-rich phase was diluted with 1 mL of a methanol solution of 0. 1 mol/L HNO3. Then 20 μL of the diluted surfactant-rich 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 preconcentration. The linear dynamic range of the copper mass concentration was found to be 0-2.0ng/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 ultratrace amounts of Cu in drinking water, tap water, and seawater samples.     

浊点萃取预富集火焰原子吸收光谱法测定水样中痕量钴

本文提出了浊点萃取预富集火焰原子吸收光谱法测定痕量钴的新方法。详细研究了溶液pH值、络合剂和表面活性剂浓度、平衡温度和时间等条件对浊点萃取效果的影响。在优化的实验条件下,本法对钴的富集倍数为20倍,检出限为3．28ng／mL,相对标准偏差(RSD)为4．1％(n=10)。所建立的方法用于自来水、湖水中痕量钴的测定,分析结果满意。     

Preconcentration and Determination of Tin in Water Samples by Using Cloud Point Extraction and Graphite Furnace Atomic Absorption Spectrometry

A method based on cloud point extraction and graphite furnace atomic absorption spectrometry (GFAAS) was developed for the analysis of trace tin in water samples. After cloud point extraction, the tin in the water samples was preconcentrated and successfully separated from most interferents. During the procedure, 8-hydroxyquinoline (8-HQ) was used as chelating reagent, and Triton X-114 was added as surfactant. The parameters affecting the sensitivity and the extraction efficiency, such as solution pH, concentration of 8-HQ and Triton X-114, equilibration temperature and centrifuge time, were evaluated and optimized. Under the optimum conditions, a preconcentration factor of 96.2 was obtained for a 20 mL water sample. The detection limit (LOD) was as low as 0.012 ng mL⁻¹, and the analytical curve was linear in the range of 0.05–2.0 ng mL⁻¹ with satisfactory precision (RSD <4.1%). The proposed method was successfully applied to the determination of trace tin in water samples with recoveries in the range of 85.0–112.0%.     

Determination of Mecruy at Trace Level in Natural Water Samples by Hydride Generation Atomic Absorption Spectrophotometry after Cloud Point Extraction Preconcentration

Mercury as a heavy metal of high toxicity is one of the most harmful elements to human beings and other creatures. Since mercury concentration in natural water is low, proper preconcentration techniques are required to increase its concentration, lower it…     

浊点萃取-火焰原子吸收光谱法测定矿渣中痕量金

研究了以双硫腙为络合剂,以非离子型表面活性剂Triton X-100为萃取剂的浊点萃取-火焰原子吸收光谱法(CPE-FAAS)测定痕量金(Ⅲ)的新方法。详细考察了溶液的pH值、络合剂和表面活性剂浓度、平衡温度和时间等条件对浊点萃取效果的影响。该方法的线性范围为0.05~0.8μg/mL,检出限为7.9 ng/mL,相对标准偏差为4.12%(n=11),回收率在98.0%~102.0%之间,用于矿渣中金的测定,结果满意。     

浊点萃取-火焰原子吸收光谱法测定样品中的痕量钴

研究了基于表面活性剂Triton X-114和络合剂吡咯烷二硫代氨基甲酸铵（APDC）浊点萃取钴的样品前处理方法.优化了浊点萃取条件参数,包括pH值、Triton X-114用量、APDC浓度、平衡温度及时间等,建立了浊点萃取-火焰原子吸收光谱法测定痕量钴的方法.该法的检测限（3σ）为2.6μg/L,相对标准偏差RSD为6.2%（n=7,c=200μg/L）.该法成功地应用于海带、维生素B12注射液等样品中钴的测定.     

浊点萃取-石墨炉原子吸收光谱法测定环境样品中的镉

建立了浊点萃取分离富集石墨炉原子吸收光谱法测定环境样品中痕量镉的方法.浊点萃取选择8-羟基喹啉为螯合剂,Triton X-100为表面活性剂.在pH 8～9、0.01%8-羟基喹啉和0.2%-Triton X-100、80 ℃水浴20 min的优化条件下,所建立方法的检出限为2.5 ng/L; 加标回收率为94.6%～106.2%; 对样品溶液进行富集的富集因子为17.利用该方法分别测定了2个实际水样和2个国家标准参考物质中的总镉含量,结果令人满意.     

浊点萃取-石墨炉原子吸收光谱法测定环境样品中的痕量镉

研究了浊点萃取-石墨炉原子吸收光谱法(GFAAS)测定痕量镉的新方法,利用表面活性剂Triton X-100和络合剂1-(2-吡啶偶氮)-2-萘酚(PAN)对镉进行浊点萃取。详细探讨了影响浊点萃取及测定灵敏度的因素。优化条件为:0.25 mL 30%NaC l,pH 8.5,0.50 mL、4.0×10-4mol/L PAN,0.2 mL 1.0%TritonX-100。在最佳条件下,镉的富集倍率为50倍,检出限为5.9 ng/L,RSD为2.1%。该方法用于环境样中痕量镉的富集和测定,结果令人满意。     

浊点萃取–火焰原子吸收光谱法分析水样中铬的存在形态

将浊点萃取与火焰原子吸收光谱法联用对水样中铬的形态进行检测,在pH 7.7条件下,络合剂1-(2-吡啶偶氮)-2-萘酚(PAN)只与Cr(Ⅲ)络合而不与Cr(Ⅵ)反应,实现了环境水样品中Cr(Ⅲ)与Cr(Ⅵ)的分别测定。对影响浊点萃取效率的主要因素如酸度、试剂量、反应温度、时间等进行了研究,在最佳条件下,铬富集倍数为20倍。Cr(Ⅲ)的质量浓度在0.005~1.0 mg/L内与吸光度线性良好,线性相关系数r=0.999 8。用该方法对0.30 mg/L的Cr(Ⅲ)标准溶液平行测定11次,测定结果的相对标准偏差为2.9%,检出限为5.74μg/L。将该法用于自来水、河水、三亚温泉水、工厂污水水中铬的形态分析并进行加标回收试验,回收率为90.0%~106.5%。该法富集倍数高、重现性好,测定结果准确可靠。     

浊点萃取-电热原子吸收光谱法分析铬的形态

提出了测定铬形态的新方法——浊点萃取-电热原子吸收光谱法(PPE-ETAAS)。该法基于利用非离子表面活性剂Triton X-100的浊点现象，当加热至其浊点时，溶液分为两相，Cr(Ⅲ）与8-羟基喹啉形成的疏水性螯合物进入富胶束相中，从而实现与Cr(Ⅵ）的分离。在本法中，8-羟基喹啉既作为化学分离，富集剂，又作为ETAAS测定中的化学改进剂。对影响浊点萃取分离的主要因素进行了详细的研究。在最优实验条件下，方法测定Cr(Ⅲ）的检出限为0．023μg/L；相对标准偏差为1．1％(C=2．0μg/L，n=6)。本法具有简便、灵敏、富集倍数高和避免使用有机溶剂的优点。     

浊点萃取-氢化物发生原子吸收光谱法测痕量汞

提出了浊点萃取预富集氢化物发生-原子吸收光谱法测定痕量汞的新方法。详细探讨了溶液pH值、表面活性剂浓度、平衡时间等因素对浊点萃取效果的影响。在优化的实验条件下,该法对汞的富集倍数为20倍,检出限为0.039μg/L,相对标准偏差(RSD)为4.8%(n=11)。所建立的方法用于天然水中痕量汞的测定,分析结果满意。     

Determination of Adrenaline by Atomic Absorption Spectrometry Using Copper as Probe Reagent in Pharmaceutical and Serum Samples

In this paper, an atomic absorption spectrometric method has been established to determine adrenaline using Cu(II) as probe reagent. In the presence of SCN^?, it has been demonstrated that Cu(II) is reduced to Cu(I) by adrenaline at pH 6.0, and the in situ formed Cu(I) reacts with SCN‐ to form the white emulsion of CuSCN. According to the amount of residual Cu(II) which is measured by atomic absorption spectrometry, the amount of adrenaline can be determined indirectly. Beer's law is obeyed in the range of adrenaline concentration of 0.080‐6.00 mg mL‐1, and the linear regression equation is A = 0.20342 ‐ 0.02756C (μg mL^?1) with a correlation coefficient of 0.9998. The detection limit is 0.033 μg mL^?1 and R.S.D. is 0.56%. This method has been successfully applied to determine adrenaline in pharmaceutical and serum samples with satisfactory results.     

浊点萃取-流动注射电感耦合等离子体原子发射光谱法同时测定水中镉钴铜镍锌

本文提出了浊点萃取-流动注射电感耦合等离子体原子发射光谱（FI—ICP—AES）法同时测定水中镉、钴、铜、镍、锌的新方法。利用5-Br—PADAP将待测金属离子转化为水不溶性的螯合物，并萃取到表面活性剂Triton X-114的浓缩相，以乙醇-硝酸溶液稀释含富集离子的浓缩相，并以FI—ICP-AES法测定。考察了流动注射进样体积、积分时间、萃取体系介质酸度、螯合剂和表面活性剂用量等实验条件的影响。在折衷条件下，镉、钴、铜、镍和锌的浓缩倍率可达18、10、16、10和8，检出限分别为0．7μg／L、1．6μg／L、1．3μg／L、5．7μg／L、3．2μg／L。方法成功应用于自来水、河水和海水中痕量镉、钴、铜、镍和锌的分析。在0．02mg／L和0．10mg／L二个水平进行加入回收试验，回收率在80％与118％之间。     

A Pre-Concentration Procedure Using Cloud Point Extraction for the Determination of Manganese in Saline Effluents of a Petroleum Refinery by Flame Atomic Absorption Spectrometry

This paper describes the development of a cloud point extraction procedure for the determination of manganese in saline effluents by flame atomic absorption spectrometry (FAAS). The optimization step was performed using the Doehlert matrix involving the following variables: buffer concentration, pH and centrifugation time. The validation process was assessed as: parameters of the analytical curve, precision, effect of other ions in the proposed procedure, robustness test and accuracy. The proposed procedure allows the determination of manganese with a detection limit (3δ/S) of 0.60 μg L⁻¹, and a precision expressed as relative standard deviation (RSD) of 2.2 (n = 8) and 1.5% (n = 8) for a manganese concentration of 1 and 5 μg L⁻¹, respectively. The pre-concentration factor obtained was 84. The recovery achieved for the determination of manganese in the presence of several other metal ions demonstrated that this procedure could be satisfactorily applied to the analysis of environmental samples. The accuracy was confirmed by the analysis of CRM trace elements in water (NIST 1643d). This procedure was applied to the determination of manganese in saline effluents of a petroleum refinery. For three analyzed samples the manganese content varied between 44.9 and 67.9 μg L⁻¹.     

Indirect Determination of Sulfadiazine by Cloud Point Extraction/Flow Injection‐Flame Atomic Absorption (CPE/FI‐FAAS) Spectrometry

An indirect simple and rapid cloud point extraction is proposed for separation and preconcentration of sulfadiazine and its determination by flow injection‐flame atomic absorption spectroscopy (FI‐FAAS). The sulfadiazine from 35 mL of solution was readily converted to silver sulfadiazine upon addition of silver nitrate (9.7 × 10^‐5 mol/L). Then, Triton X‐114 a non ionic surfactant was added and the solution was heated to 60 °C. At this stage, two separate phases was formed and silver sulfadiazine enters the surfactant rich phase of non‐ionic micelles of Triton X‐114. The surfactant‐rich phase (～50 μL) was then separated and diluted to 300 μL with acidic methanol. The concentration of silver in the surfactant‐rich phase which is proportional to the concentration of sulfadiazine in sample solution was determined by FI‐FAAS. The parameters affecting extraction and separation were optimized. Under the optimum conditions (i.e. pH 2‐10, silver concentration (9.7 × 10 ^‐5 mol/L), Triton X‐114 (0.075% v/v) and temperature 60 °C) a preconcentration factor of 117 and a relative standard deviation of 4.9% at 37 μg L^‐1 of sulfadiazine was obtained. The method was successfully applied to analysis of milk, urine and tablet samples and accuracy was determined by recovery experiments.     

Cloud Point Preconcentration and Flame Atomic Absorption Spectrometric Determination of Cobalt and Nickel in Water Samples

 Cloud point methodology was successfully used to preconcentrate trace amounts of Co and Ni as a prior step to their determination by flame atomic absorption spectrometry. 1-Nitroso-2-naphthol and polyethylene glycol-p-nonylphenylether (PONPE 7.5) are used as hydrophobic ligand and nonionic surfactant, respectively. Optimization was performed of the variables effecting complexation and phase separation. Additionally, the influence of viscosity on the analytical signal was investigated. Under the experimental conditions used, preconcentration of only 10 mL of sample in the presence of 0.075% (v/v) PONPE 7.5 permitted the detection of 1.09 μg L⁻¹ of Ni and 1.22 μg L⁻¹ of Co with enhancement factors of 29 and 27 for Ni and Co, respectively. The relative standard deviations (n=5) at concentrations of 80 and 50 μg L⁻¹ for Co and Ni were 2.53 and 2.89%, respectively. Good recoveries in the range of 96–105% were obtained for spiked samples. The effect of different interferent species was studied. The proposed method was applied to the determination of Ni and Co in different water samples. Correspondence: Department of Analytical Chemistry, Faculty of Chemistry, Tabriz University, Tabriz, Iran. e-mail: manzoori@tabrizu.ac.ir Received September 1, 2002; accepted November 8, 2002     

浊点萃取-火焰原子吸收光谱法测定菠菜中镁、锌和铜

在pH 8.0缓冲溶液中,以8-羟基喹啉为螯合剂,镁、锌和铜均与8-羟基喹啉生成螯合物,加入Triton X-100表面活性剂用浊点萃取分离富集菠菜样品中镁、锌和铜。分取部分表面活性剂相用乙醇定容至25mL,所得溶液直接用火焰原子吸收光谱法进行测定。对影响浊点萃取的因素和共存离子的干扰等进行了试验并予以优化。镁、锌和铜的检出限(3s/k)依次为0.057,0.064,0.032mg.L-1。应用此法测定了大叶菠菜和小叶菠菜中3种元素的含量,在两种样品中用标准加入法进行方法的回收试验,测得镁的回收率在93.3%～100.5%之间;锌的回收率在91.7%～97.9%之间;铜的回收率在94.0%～107.1%之间。     

Cloud Point Extraction Preconcentration of Trace Cadmium as 1-Phenyl-3-methyl-4-benzoyl-5-pyrazolone Complex and Determination by Flame Atomic Absorption Spectrometry

A new method for the determination of trace cadmium in water samples by flame atomic absorption spectrometry (FAAS) after cloud point extraction (CPE) is proposed. The method is based on the complexation of Cd with 1-phenyl-3-methyl-4-benzoyl-5-pyrazolone (PMBP) 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 are 0.64 ng mL^±1 with relative standard deviations (RSDs) of 2.1% (n = 10). The proposed method was applied to the determination of trace cadmium in water samples with satisfactory results.