流动注射在线共沉淀预富集火焰原子吸收法测定痕量铜

研究了以Ｎｉ＾２＋－ＤＤＴＣ为共沉淀载体，流动注射在线共沉淀预富集－火焰原子吸收光谱法测定痕量铜的体系，在０．３ｍｏｌ．Ｌ＾－１的硝酸介质中，铜离子在编织反应器中与Ｎｉ＾２＋－ＤＤＴＣ（产生共沉淀，并被收集在编织器内壁上，用甲基异丁基酮（ＭＩＢＫ）在线洗脱沉积物并引入火争原子化器中测定。当富集时间为４０ｓ时，４０μｇ．Ｌ＾－１的铜１０次测定的相对标准偏差为３．０％，灵敏度提高６０倍，检出限（３σ）     

硅藻土吸附在线柱富集-火焰原子吸收光谱法测定环境水样中痕量铜

提出了硅藻土吸附在线柱富集-火焰原子吸收光谱法测定环境水样中痕量铜的方法。利用硅藻土对环境水样中痕量铜在线预富集,浓集因子达到27.6,使火焰原子吸收光谱法的检测能力达到测定环境水样中痕量铜的要求。方法检出限为0.32μg.L-1,RSD(20μg.L-1)为3.52%,加标回收率为97.0%~105.0%。     

螯合树脂在线富集火焰原子吸收法测定痕量铅和镉

在pH=4.88的乙酸-乙酸钠缓冲溶液中,用螯合离子交换树脂富集铅和镉,以1.50mol/L HNO3作洗脱液,火焰原子吸收法测定洗脱液中痕量铅和镉。该方法对铅和镉的线性范围分别是4.0～80.0μg/L和2.0～30.0μg/L,检出限分别为1.3μg/L和0.7μg/L。该方法用于地表水中痕量铅和镉的测定,分析结果满意。     

磁性石墨烯固相萃取/原子吸收法测定环境水样中的痕量铜

以1-(2-吡咯偶氮)-2-萘酚(PAN)为络合剂络合水样中的痕量铜,以磁性石墨烯(G)纳米材料为固相萃取吸附剂,建立了测定水样中痕量铜的磁性固相萃取/火焰原子吸收分光光度法。此方法将磁性石墨烯比表面积大、吸附性能好的优点与Fe3O4纳米粒子的磁性相结合,采用的磁性固相萃取避免了传统固相萃取中离心和过滤等繁琐的操作步骤。对影响G-Fe3O4萃取效率的实验因素进行了优化。在优化实验条件下,对铜离子的富集倍数为80.4倍,线性范围为0.5～100μg/L,相关系数(r)为0.998 1,检出限为0.067μg/L,相对标准偏差为2.1%～5.2%。此方法成功地应用于矿泉水、自来水、公园湖水中铜离子含量的测定,其加标回收率为94%～103%。结果表明,该磁性石墨烯纳米材料G-Fe3O4对水样品中铜的PAN络合物具有较高的富集能力。     

流动注射在线分离富集火焰原子吸收法测定环境样品中的铅和镉

使用PT-C18色谱预处理柱,以二乙基二硫代氨基甲酸钠（DDTC）和吡咯啶二硫代氨基甲酸铵（APDC）混合物为螯合剂,甲醇为洗脱剂,采用流动注射在线分离富集与原子吸收联且技术,对铅和镉的测定进行了研究。1min（4.2mL),检出限：Pb为6.90μg/L;Cd为0.45μg/L,相对标准偏差：Pb为2.80%;Cd为2.47%。     

用DDTC-Zn作载体流动注射在线共沉淀预富集火焰原子吸收法测定人发和水样中的痕量铅

提出了在高酸度下流动注射在线共沉淀预富集－火焰原子吸收法测定痕量铅的新体系。在０．５ｍｏｌ／ＬＨＣｌ介质中痕量铅与ＤＤＴＣ－Ｚｎ螯合物产生共沉淀。在线生成的沉淀物收集在编结反应器中，用甲基异丁酮溶解沉淀并直接引入火焰原子化器中进行测定。经４０ｓ富集，检测限为２．７μｇ／Ｌ。测定含量为２００μｇ／Ｌ的铅时，相对标准偏差为１．３％。建立的方法已成功地应用于人发标准参考物中和水样中痕量铅的测定     

螯合树脂微柱分离富集火焰原子吸收法测定地质样品中的痕量银

利用新合成的螯合树脂聚[4 乙烯苄基 (2 羟乙基硫醚)]制备微型吸附柱,采用螯合树脂微柱分离富集 火焰原子吸收法测定了地质样品中的痕量银。研究了螯合树脂微柱的吸附性能及影响吸附的因素,在稀王水介质中进行吸附,采用酸性硫脲为洗脱剂,以峰面积方式检测,测定Ag 的线性范围0.010～1.0μg mL,灵敏度提高40倍,吸附率在80%,相对标准偏差<4.2%,树脂柱可重复利用100次以上。     

在线固相萃取预富集-原子吸收联用测定痕量Fe(Ⅱ)和总铁量

以1,10-二氮菲(1,10-phen)为配合剂,乙醇为洗脱液,在C₁₈柱上将流动注射固相萃取预富集-原子吸收光谱联用测定痕量Fe(Ⅱ)和总铁.Fe(Ⅲ)的含量可通过抗坏血酸还原后用差示法测得.本法灵敏度高,选择性好,能在线分离干扰富集Fe(Ⅱ),采样速度80次/h,富集倍数19倍,检测下限为3μg/L,相对标准偏差1.1%(n=10),可用于测定水样中痕量Fe(Ⅱ)和Fe(Ⅲ),回收率为94%105%.     

流动注射-在线富集火焰原子吸收分光光度法测定痕量铅

本文报道在流动注射分析体系中用装有黄原脂棉的微型柱对溶液中Pb2 进行在线富集后,用3.0 mol/L盐酸洗脱柱上富集的Pb2 ,然后采用火焰原子吸收光谱法在线测定痕量Pb2 ,方法的线性范围为0.5～100μg/L。与未富集前相比,测定的灵敏度可提高65倍。方法用于环境水样中痕量Pb2 的测定,回收率在97.0%～102%之间,相对标准偏差小于4.0%,分析结果满意。     

硅胶负载碳纳米管分离富集水中痕量银

以NaOH为沉淀试剂,将水样中的Ag+在线生成Ag2O沉淀,并即时被滞留在硅胶负载的碳纳米管表面。被吸附的Ag2O沉淀用HNO3(10%,V/V)洗脱,并用火焰原子吸收法检测。当进样体积为5.4mL时,线性范围为1～120μg/L,富集系数为34.5;检出限为0.35μg/L;相对标准偏差为0.5%(40μg/L,n=7),采样频率为47次/h。结果表明:本方法的富集系数、检出限及精密度均明显优于以纯碳纳米管和纯硅胶微珠为吸附剂收集Ag2O的体系。将此系统应用于实际水样中银的测定,加标回收率在96%～108%之间。     

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.     

壳聚糖富集火焰原子吸收法测定水中痕量铜

采用壳聚糖修饰钨丝基质螺旋卷，直接浸入含有痕量铜的pH5．0的Brltton-Robinson缓冲溶液中，经电磁搅拌富集一定时间后，将其转移至空气／乙炔火焰燃烧器上，利用火焰原子吸收光谱法简便快速测定水中痕量铜。方法的线性范围为2—75μg／L；检出限为0．98μg／L。同一支钨丝螺旋卷重复涂敷壳聚糖富集Cu，RSD(n=6)为2．7％。     

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。     

Online Preconcentration Using Surfactant Coated Alumina Modified with 1,5-Diphenylthiocarbazone and Determination of Cadmium in Environmental Samples by Flame Atomic Absorption Spectrometry

A rapid and sensitive method for the determination of trace levels of cadmium in cigarettes, soil, and blood samples by flame atomic absorption spectrometry (FAAS) has been developed. It is based on the online sorption of Cd(II) ions on a minicolumn packed by sodium dodecyl sulfate–coated alumina modified with dithizone. The optimum experimental parameters for the adsorption and desorption of cadmium were investigated. The recovery obtained was found to be 96% with preconcentration factor of 150. The calibration curve was linear between 50–600 µg/L Cd with a detection limit of 3 µg/L, sample frequency of 30 h^?1 and reuse of column for 10 times without loss of sensitivity. The accuracy of the method was confirmed by applying the standard addition method and quantitative recoveries (95–99%) were obtained.     

Determination of Copper in Mineral Waters from Galicia, Spain, by Flame Atomic Absorption Spectrometry Using Preconcentration with Diethyldithiocarbamate Loaded on Silica Gel

Solid phase extraction using sodium diethyldithiocarbamate (DDC) loaded on silica gel has been used for preconcentration of trace amounts of copper from commercial mineral waters prior to its determination by flame atomic absorption spectrometry. The sorption and releasing of copper have been studied under both static and dynamic conditions. A short shaking time is required for quantitative sorption using the batch method, and a high flow-rate (6 ml min⁻¹) can be used in the column method due to the fast sorption and desorption kinetics. The copper concentration found in several mineral waters from Galicia (Spain) ranged from 8.4 to 23.8 μg L⁻¹. There were no significant differences between the solid-phase extraction method and the conventional solvent extraction method which uses DDC as chelating agent.     

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.     

Preconcentration of Trace Cadmium (II) and Copper (II) in Environmental Water Using a Column Packed with Modified Silica Gel-Chitosan Prior to Flame Atomic Absorption Spectrometry Determination

A new column loaded with modified silica gel-chitosan is proposed as a preconcentration system for adsorption of trace cadmium (II) and copper (II). The optimization steps were performed under dynamic conditions, involving pH, sample flow rate, eluent selection, concentration, volume, and flow rate. Trace Cd(II) and Cu(II) were quantitatively adsorbed by the modified silica gel-chitosan. The metal ions adsorbed on the separation column were eluted with 0.1 M HNO₃ and determined by flame atomic absorption spectrometry. Under the optimum conditions, this method allowed the determination of cadmium and copper with limits of detection (LOD) of 20 ng L^?1 and 38 ng L^?1, respectively. The relative standard deviation values (RSDs) for 1.0 mg L^?1 of cadmium and 1.0 mg L^?1 of copper were 2.62% and 2.85%, respectively.