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%.     

Flame Atomic Absorption Spectrometry Determination of Tin In Canned Foods After Extraction With Liquid Chelating Exchanger

Abstract

A combined β-diketo liquid chelating exchanger, LCE (RCOCH₂COCF₃; R = C₉H₁₉), separation followed by flame atomic absorption spectrometry method is described for the determinatoin of tin in canned foods. the optimum conditions for the separation and preconcentration of tin e.g., pH, solvent, exchanger concentration, time, effect of various ions and nature of the extracted species have been discussed. Quantitative extraction (100%) of tin with LCE occurs in cyclohexane medium at pH 5.8, the extracted species being . The results of the determination of tin in five canned food samples were as follows (in mg/kg): orange juice, 97.31 ± 0.71; pineapple juice; 145.85 ± 0.59; tomato juice, 70.54 ± 0.91; chicken soup, 21.30 ± 0.65; Vegetable soup, 65.24 ± 0.93. the reliability of the present method has been tested from the recoveries (98.4-101.7%) of tin after adding various known amounts to pineapple juice and vegetable soup solutions.     

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。     

磁性纳米材料固相萃取/火焰原子吸收光谱法测定环境水样中的痕量银离子

在纳米四氧化三铁表面包覆二氧化硅,并以十八烷基三甲氧基硅烷进行化学修饰,用作固相萃取吸附剂富集环境水样中的痕量银离子,用火焰原子吸收光谱法测定,建立了一种灵敏、快速、简便分析银离子的新方法。考察了水样pH值、吸附剂用量、螯合剂用量、振荡时间、洗脱剂、共存离子等对银离子回收率的影响。实验结果表明,对于200 mL水样,在pH 7.0、吸附剂用量为0.1 g、螯合剂5-Br-PADAP(0.5 g/L)用量为0.6 mL、吸附时间为10 min的条件下,材料对Ag+具有较好的吸附性,且用6 mL 1.0 mol/L的硝酸可完全洗脱所吸附的Ag+。在优化实验条件下,检出限(3σ)为0.15μg/L,相对标准偏差(10μg/L,n=6)为1.4%,富集因子达31。分别对河水、湖水样品中Ag+进行检测,加标回收率为85.0%~94.8%。     

离子液体[Bmim]PF6萃取-火焰原子吸收法测定水中痕量镉

1引言化学工业排放的废水含有大量金属镉,对环境产生严重危害,因而环境水样中痕量镉的准确测定具有重要意义。目前,常用原子吸收光谱法[1]测定痕量的镉,但由于环境水样中镉的含量低且样品复杂,为了提高分析方法的灵敏度和选择性,样品的预分离与富集至关重要。液-液萃取是一种常用的预分离与富集方法,但常用有机溶剂作萃取剂,易带来二     

火焰原子吸收光谱法测定锡渣中的铟

采用了四种溶样方法,通过对四种方法得到的数据评估后采用混合熔剂熔样,最终建立了一种利用火焰原子吸收光谱法测定锡渣中铟的方法,在硝酸介质中,于波长303.9nm处,用火焰原子吸收光谱法测定,并采用标准加入法测定样品中干扰难以排除的元素。方法简便、实用,具有较高的精密度和准确度,方法的相对标准偏差为0.74%~1.0%,加标回收率为96.21%~103.76%。     

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.     

火焰原子吸收光谱法直接测定锡阳极泥中的银

建立了火焰原子吸收光谱法(FAAS)测定锡阳极泥中银含量的方法。文章考察了不同的测定介质、酸度对测定结果的影响。实验结果表明在选定条件下,锡阳极泥中的锡、锑、铅等杂质不干扰银的测定。方法加标回收率在99.2%~103%,精密度实验结果表明,相对标准偏差(RSD,n=11)均小于4%。操作过程简单,能满足生产的需要。     

Preconcentration and Determination of Trace Amounts of Heavy Metals in Water Samples Using Membrane Disk and Flame Atomic Absorption Spectrometry

A fast and simple method for preconcentration of Ni^2＋, Cd^2＋, Pb^2＋, Zn^2＋, Cu^2＋ and Co^2＋ from natural water samples was developed. The metal ions were complexed with sodium diethyldithiocarbamate （Na-DDTC）, then adsorbed onto octadecyl silica membrane disk, recovered and determined by FAAS. Extraction efficiency, influence of sample volume and eluent flow rates, effects of pH, amount of Na-DDTC, nature and amount of eluent for elution of metal ions from membrane disk, break through volume and limit of detection have been evaluated. The effect of foreign ions on the percent recovery of heavy metal ions has also been studied. The limit of detection of the proposed method for Ni^2＋, Cd^2＋, Pb^2＋, Zn^2＋, Cu^2＋ and Co^2＋was found to be 2.03, 0.47, 3.13, 0.44, 1.24 and 2.05 ng·mL^-1, respectively. The proposed （DDTC） method has been successfully applied to the recovery and determination of heavy metal ions in different water samples.     

氢化物发生辅助雾化火焰原子吸收法测定水中铅

研究了一种提高火焰原子吸收测定铅灵敏度的新方法——氢化物发生辅助雾化的火焰原子吸收法；方法采用硼氢化钠与铅(Ⅳ)在原火焰原子吸收雾化器喷口处反应生成氢化物，以提高火焰原子吸收法的雾化效率；采用重铬酸钾一酒石酸预处理体系，重铬酸钾氧化样品中铅(Ⅱ)为铅(Ⅳ)，酒石酸稳定铅(Ⅳ)的亚稳态化合物；对各种实验参数和干扰情况也进行了研究；方法操作简单、快速，灵敏度比通常的火焰原子吸收法提高了6．8倍；检出限(K=3，n=11)为6．64μg/L，线性范围为0．021～3．2mg／L；测定水样的回收率达94％～99％。     

1-亚硝基-2-萘酚浊点萃取-火焰原子吸收光谱法对水样中痕量铁的测定

采用以1-亚硝基-2-萘酚为螯合剂、Triton X-114为表面活性剂的新型浊点萃取体系富集水中的痕量铁,并用火焰原子吸收光谱法对铁进行测定。详细探讨了溶液pH值、表面活性剂浓度、络合剂浓度、平衡温度、平衡时间等对浊点萃取及测定灵敏度的影响,优化了实验条件。在最佳条件下测得铁的检出限（S／N=3）为0．42μg&#183;L^-1,富集倍数为32,校准曲线相关系数为0．996。应用该法测定海水、湖水及自来水中的痕量铁,结果满意。     

Combination of Dispersive Liquid‐Liquid Microextraction with Flame Atomic Absorption for Determination of Trace Ni and Co in Water Samples and Vitamin B12

A dispersive liquid‐liquid microextraction method based on the dispersion of 1,2‐dichlorobenzene as an extraction solvent into an aqueous phase in the presence of ethanol as a dispersive solvent for the preconcentration of Co²⁺ and Ni²⁺ ions is discussed. 1‐Nitroso 2‐naphtol was used as a chelating agent prior to the extraction and the preconcentrated analyte was determined by flame atomic absorption spectrometry. The effect of various experimental parameters including the extraction and dispersive solvent type and volume, pH, amount of the chelating agent, etc. on the microextraction and complex formation was investigated for finding the optimum conditions. The enhancement factors were about 61.9 and 51.8, the calibration graphs were linear in the range of 10‐150 μgL^?1 and 10‐250 μgL^?1 with detection limits of 2.42 μgL^?1 and 1.59 μgL^?1, and RSD (n = 5) of 3.08% and 2.17% for cobalt and nickel, respectively. The method was successfully applied to the determination of Co and Ni in water and vitamin B₁₂.     

火焰原子吸收光谱法测定锡阳极泥中铜的含量

建立了火焰原子吸收光谱法测定锡阳极泥中铜元素的分析方法。对锡阳极泥样品,采用盐酸、硝酸、高氯酸分解,氢溴酸挥发除去锡和锑的溶样方式,火焰原子吸收光谱仪测定铜,测定范围为1%～5%,并考察了仪器条件、不同酸浓度、干扰元素对铜含量测定的影响。实验结果表明铜的检出限为0.013μg/mL,加标回收率为95.5%～104%,相对标准偏差为0.81%～2.1%,方法准确度高、精密度好,能够很好地满足锡阳极泥中铜元素的测定。     

火焰原子吸收光谱法快速测定水性漆中镉

研究了水性漆中镉的原子吸收法分析。采用干灰化法处理漆片试样,硝酸消解,ＦＡＡＳ测定,加标回 在８７．８￣９６．４％     

Determination of Trace Butyltin Compounds in Sea Water by Gas Chromatography-Atomic Absorption Spectrometry

A gas chromatography-atomic absorption spectrometric (GC-AAS) method has been developed for the determination of trace butyltin compounds in sea water. Aqueous butyltin compounds were reduced to the volatile hydride forms by NaBH₄ and were extracted with dichloromethane simultaneously. The dichloromethane extract was concentrated under reduced pressure, followed by direct injection into the GC-AAS system for analysis. The butyltin species were separated with a 2-m glass column packed with 2% OV-101 on Chromosorb G HP (100-120 mesh). Following GC separation, each species was transferred into an electrothermally heated (800 °C) quartz furnace for atomization. The tin atoms produced from individual butyltin compound were detected at 224.6 nm by an atomic absorption spectrometer. With a sea water sample (1 L), the detection limits (3σ) for monobutyltin, dibutyltin and tributyltin were approximately 20, 20 and 70 ng Sn L^?1, respectively. The method has been applied to the analysis of trace butyltin compounds in the sea water of Keelung Harbor.     

Determination of Hg(II) in Environmental Water Samples by Dispersive Liquid Phase Microextraction Combined with Flame Atomic Absorption Spectrometry

In this study, a method of dispersive liquid phase microextraction combined with the flame atomic absorption spectrometry was proposed for the determination of trace Hg using diphenylthiocarbazone as chelating reagent. Several factors which have effect on the microextraction efficiency of Hg, such as pH, extraction and dispersive solvent type and their volume, concentration of the chelating agent, extraction time were investigated, and the optimized experimental conditions were established. After extraction, the enrichment factor was 68. The detection limit of the method was 45 ng mL^?1, and the relative standard deviation for eight determinations of 2 μg mL^?1 Hg was 1.7%. The results for the determination of Hg in environmental water samples (tap water, well water, mineral water and Caspian sea water) have demonstrated the applicability of the proposed method.     

石墨炉原子吸收法测定化探样品中的微量锡

建立用C型石墨管和具有赛曼效应的石墨炉原子吸收法测定化探样品中微量锡的方法。样品在刚玉坩埚中用KOH熔融后沸水提取定容,样品溶液酸化后无需加入基体改进剂直接用石墨炉原子吸收法测定。锡的质量浓度在0~20 ng/m L范围内与吸光度呈良好的线性,线性相关系数r2=0.995 6,检出限为0.08μg/g。用该法对国家一级标准物质进行测定,测定值在标准值不确定度范围内,重复测定结果的相对标准偏差不大于7.75%(n=12)。该方法操作简便、快速,适用于区域化探样品中微量锡的测定。     

溶剂萃取-石墨炉原子吸收光谱法测定水样中的痕量铅

本文采用2-(5-溴-2-吡啶偶氮)-5-二乙氨基苯酚(5-Br-PADAP)为络合剂,辛醇为提取剂,提出了有机溶剂萃取-石墨炉原子吸收光谱测定水样中痕量铅的分析方法。对萃取和石墨炉升温条件进行了优化。在本实验条件下,方法的线性范围在0.5~5.0μg/L之间,检出限为0.067μg/L,相对标准偏差(RSD)为3.9%(n=7),回收率在89%~97%范围。本法与未经溶剂萃取的方法相比,线性斜率提高了约20倍。本法已用于环境水样中痕量Pb的测定,测定结果与ICP-MS的分析结果具有良好的一致性。     

Selective Determination of Copper in Water Samples by Atomic Absorption Spectrometry after Cloud Point Extraction

A preconcentration methodology utilizing the cloud point phenomenon is described for the determination of copper by flame atomic absorption spectrometry. The reagent Sulfathiazolylazo resorsin was used as a complexing agent. The preconcentration factor of 25-fold was obtained. The calibration curve is linear in the range of 4–400 µ g L^?1 with a limit of detection of 0.64 µ g L^?1. The relative standard deviation (n = 5, 12 µ g L^?1) was 3.5%. The cloud point is formed in the presence of phenol at room temperature. The method was successfully applied to the determination of copper in water samples and a standard reference material.