浊点萃取电热原子吸收光谱法测定水中痕量铊

采用吡咯烷基二硫代氨基甲酸铵(APDC)为螯合剂,Triton X-114作为表面活性剂,建立了浊点萃取预富集电热原子吸收光谱法测定水中痕量铊的方法。在优化的实验条件下,方法的检出限可达0.07μg/L,相对标准偏差为3.6%(4μg/L,n=7),加标回收率为93%~106%,富集倍率为31。该方法成功应用于自来水和河水中痕量铊的测定。     

浊点萃取掺氧空气-乙炔火焰原子吸收光谱法测定痕量铝

本文提出铬天青S作为掺氧空气-乙炔火焰原子吸收光谱法(FAAS)测定痕量Al 3+的化学改进剂,又作为萃取Al 3+的络合剂。优化了浊点萃取痕量Al 3+的分离富集条件,及掺氧空气-乙炔FAAS测定Al 3+的参数。据此,建立了选择性好﹑简便快速测定水样中痕量Al 3+的新方法。方法的检出限(3σ)为4.5μg/L,测定Al 3+的线性范围为15~1 600μg/L,相对标准偏差(RSD)是3.8%(cAl=100μg/L,n=7),加标回收率在96.1%~105.9%之间,理论富集倍数为50。     

流动注射在线预分离富集-火焰原子吸收光谱法测定中成药中的痕量镉

应用D-411鳌合树脂作在线分离预富集柱填料,流动注射与原子吸收光谱联用测定中成药中的痕量镉。采样频率28次/h,富集倍数达46倍,线性范围0～0.020mg/L,该方法的检出限(3S,n=10)0.0285μg/L,相对标准偏差5.2%。将该方法用于中成药样品中镉的测定,结果满意。     

巯基棉分离富集-石墨炉原子吸收法测定痕量铟的研究

研究了巯基棉(SCF)富集痕量In(Ⅲ)的条件,并用石墨炉原子吸收光谱(GFAAS)法测定痕量In(Ⅲ)。结果表明,在pH=4.0时,巯基棉能定量富集痕量In(Ⅲ),其饱和吸附量为181μg/g。吸附的In(Ⅲ)可被0.8 mol/L的HNO3定量洗脱。本法用于人工合成铝基、锌基样品和锌精矿中痕量In(Ⅲ)的富集和测定,回收率为92.8%~100.6%。     

磁芯-硫脲壳聚糖微柱在线流动注射-原子吸收光谱法测定大米中痕量镉

本文将磁芯-硫脲壳聚糖作为固定相填充到自制的微柱中,采用流动注射在线分离富集与火焰原子吸收法联用对大米中痕量镉进行测定。pH=7.0的试液以3.9mL/min速率采样120s,以0.5mol/L HNO3-0.1mol/L硫脲作为洗脱液,用火焰原子吸收光谱法测定洗脱液中Cd2+,检测的线性范围为0.02~1.20μg/mL(r=0.9922),检出限(3σ)为2.5ng/mL,相对标准偏差(RSD)为0.79%(c=1.0μg/mL,n=7),加标回收率在96.0%~104.2%之间。     

氨丙基硅三烷改性介孔二氧化硅及对痕量镉(Ⅱ)的分离富集性能研究

以氨丙基硅三烷作为改性剂,对介孔二氧化硅表面进行修饰,制备了氨基化介孔二氧化硅吸附材料,采用透射电镜和傅立叶红外光谱仪对其进行表征,并用于水样中痕量镉的富集,建立了氨基化介孔二氧化硅分离预富集/火焰原子吸收光谱法测定痕量镉的方法。考察了溶液pH值、样品流速、洗脱剂类型、干扰离子和吸附容量等对痕量镉分离富集的影响,以及该吸附材料对痕量镉(Ⅱ)的吸附性能。结果表明,溶液pH 7.0,样品流速8 m L/min时镉离子能被制备材料高效吸附,吸附的镉(Ⅱ)用5.0 m L 2 mol/L HNO_3完全洗脱,火焰原子吸收法测定。在最佳实验条件下,方法的线性范围为0.6~20 ng/m L,定量下限为0.5 ng/m L,富集倍数为50倍,对10 ng/m L Cd2+测定的相对标准偏差(n=11)为0.92%,加标回收率为98.8%~104.5%。该方法的抗干扰能力较好,富集柱可循环使用12次以上,可用于环境水样中镉(Ⅱ)的测定。     

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%。     

铋膜电极溶出伏安法测定食品中痕量重金属

以铋膜电极为工作电极,采用微分脉冲阳极溶出伏安法直接测定食品样品中痕量铅、镉和锌。在富集电位-1.4V,富集时间180s,铋膜质量浓度150μg·L-1的条件下,铋膜电极对铅、镉和锌的氧化溶出具有良好的电化学响应。铅(Ⅱ)、镉(Ⅱ)和锌(Ⅱ)的质量浓度在5.0~40μg·L-1的范围内与其阳极溶出峰电流呈线性关系,铅(Ⅱ)、镉(Ⅱ)和锌(Ⅱ)的检出限(3S/N)分别为0.80,0.65,0.58μg·L-1。对25μg·L-1铅(Ⅱ)、镉(Ⅱ)和锌(Ⅱ)溶液用铋膜电极连续测定15次,相对标准偏差分别为6.2%,5.1%,7.1%。方法应用于食品中痕量重金属的测定,测定结果与石墨炉原子吸收光谱法的测定值相符。     

流动注射双硫腙在线共沉淀预浓集石墨炉原子吸收光谱法测定人血中微量镉

本文用流动注射分析技术为石墨炉原子吸收光谱法测定人血中超微量金属元素建立了一个有效的在线共沉淀分离预浓集系统。基于痕量镉与双硫腙(DTZ)在弱酸性水溶液中共沉淀。沉淀收集在一编结反应器及一微型过滤器上,用60μL甲基异丁基酮(MIBK)溶洗沉淀,然后送入石墨炉进行测定。分析速度24样/h,样品消耗为1.4mL,获得的富集倍率为11。检出限(3σ)为0.003μg/L,浓度为0.06μg,/L镉时,测定精度为2.6%(n=7),测定人体血样标准参考物(GBW09132～GBW09134)中镉,结果与标准值一致。     

氧化石墨烯/硫杂杯芳烃复合材料富集分离-石墨炉原子吸收法测定痕量铊

自制了一种新型氧化石墨烯/硫杂杯芳烃复合材料,用扫描电镜、红外光谱、元素分析、热分析对合成产品进行表征,用于痕量铊的富集,提出了氧化石墨烯/硫杂杯芳烃复合材料分离预富集,石墨炉原子吸收光谱法测定痕量铊的一种新方法,探讨了溶液pH值、温度、洗脱条件及干扰离子对痕量铊分离富集的影响,结果发现该材料对Tl3+具有较大吸附量。在pH 8.0,温度为(23±1)℃条件下,铊可被该材料定量吸附,其吸附容量为73.1 mg/g。吸附的铊可被5.0 mL酸性硫脲(0.5 mol/L HCl+1.0 mol/L硫脲)完全洗脱,方法的线性范围为0.012~15μg/L,检出限(3σ)为0.008μg/L,对0.50μg/L Tl3+工作液测定的RSD(n=7)为2.3%,加标回收率为93.6%~104.1%。此法用于生物样品和环境水样中痕量铊的测定,结果满意。     

电化学-原子吸收光谱法联用测试中影响因素的分析

对电化学与火焰原子吸收光谱仪联用中测试的几种主要影响因素进行了探讨。试验的影响因素包括电化学预富集池填同料的大小及填充厚度、溶液底液支持电角质的种类及浓度、溶出阶段支持电解质的类型及浓度、电化学预富集电压及溶出测定阶段的反高电压的大小和流动液的流速。在选定的条件下,经对铜离子的试验可使检出限降低２个数量级。     

Determination of cadmium by electrothermal atomic absorption spectrometry using electrochemical separation in a microcell

Electrodeposition on the graphite electrode under conditions of controlled current in a flow-through mode, followed by electrothermal atomic absorption spectrometry, is proposed for the determination of cadmium. After electrolysis in a microcell of 2.6 μl volume, deposited metal was dissolved in 40 μl 0.2 mol l⁻¹ HNO₃ and the whole volume was direct injected into the atomizer. Using this on-line arrangement and electrodeposition from 1.75 ml of sample solution detection limit of 25 ng l⁻¹ Cd was attained. The method was applied for the determination of cadmium in a real sample of seawater.     

Essais interlaboratoires: dosage du cadmium,du cuivre et du plomb dans l'eau de mer par spectrometrie d'absorption atomique electrothermique: |en|An in terlaboratory study of the determination of cadmium,copper and lead in seawater by electrothermal atomic absorption spectrometry

An in terlaboratory study of the determination of cadmium, copper and lead in seawater by electrothermal atomic absorption spectrometry.The reproducibility of a selective extraction method on Chelex-100 resin in the Ca²⁺ form, described previously, was tested on seawater with and without addition of Cd, Cu and Pb. The metals extracted were determined by electrothermal atomic absorption spectrometry (a.a.s.). The results obtained by the three laboratories participating in these tests prove the validity of the method for the determination of cadmium and copper. The largest dispersion of results, observed for lead, is related to the poorest precision of electrothermal a.a.s. for this element.     

Determination of Nickel,Manganese, Copper and Zinc in Blood Serum by Atomic Absorption Spectrometry after Deproteinization by Microwave Irradiation

ABSTRACT

Deproteinization of serum was performed by microwave irradiation combined with a small volume of diluted trichloracetic acid. The procedure reduced the protein level of the samples to less than 99% of the total with a small dilution factor (1+1) and allowed the determination of nickel and manganese by electrothermal atomic absorption spectrometry and copper and zinc by flame atomic absorption spectrometry directly without modifiers or matrix interferences. As metallic ions are normally bonded to serum proteins they must be released during protein precipitation. Spiked serum samples were submitted, before the deproteinization, to an incubation treatment to bond the added ions to the proteins. To check the efficiency of the incubation time for each ion, serum samples were ultrafiltered at set time intervals and the metals determined in the ultrafiltrate. The proposed method was compared with the common deproteinization by acids for the separation of the proteins. The reduction of proteins allowed a small dilution of the sample and the use of faster temperature programmes for the determination of nickel and manganese by electrothermal atomic absorption spectrometry and the aspiration of samples more similar to aqueous standards for copper and zinc determination by flame atomic absorption spectrometry. Recoveries from spiked, incubated and deproteinized samples compared to only diluted samples show that the method can satisfactorily be used for atomic absorption spectrometric determination of these elements.     

Comparison of electrothermal atomic absorption spectrometry of the metal content of sewage sludge with flame atomic absorption spectrometry in conjunction with different pretreatment methods

Determination of the metal content of sewage sludges is of increasing importance in order to assess the suitability of the sludge for disposal to agricultural land. The methods currently used for the determination of cadmium, chromium, copper, nickel, lead and zinc are time-consuming. A rapid electrothermal atomic absorption procedure with homogenization as the only pretreatment is compared with wet and dry pretreatment methods followed by flame atomic absorption spectrometry, in a statistically designed experiment. The precision of the rapid electrothermal atomic absorption procedure compares well with flame atomic absorption in conjunction with all pretreatment methods used. Time saved by the use of this method is substantial; the procedure could be used advantageously for routine analysis.     

Determination of palladium in sulfide-bearing rocks by electrothermal atomization atomic absorption spectrometry with a continuous spectrum source

A possibility of the direct determination of palladium in dissolved samples of platinum sulfide ores by high-resolution electrothermal atomic absorption spectrometry with a continuous light source without preconcentration and separation from the matrix components is investigated. The conditions of analysis are selected and a procedure for the determination of palladium is developed. The results of determination well agree with the data obtained using extraction separation and traditional atomic absorption spectrometry with selective line spectrum sources. The accuracy of the results was estimated by the added–found method.     

Reduction des interferences sur la determination des metaux lourds dans les sediments de cours d'eau et les boues de stations d'epuration par spectrometrie d'absorption atomique en four graphite

(Reduction of interferences in the determination of trace heavy metals in river sediments and sewage sludges by electrothermal atomic absorption spectrometry.)The interferences of synthetic matrices of river sediments and sewage sludges in the determination of lead, copper, cadmium, chromium and nickel by electrothermal atomic absorption spectrometry were studied; Pb, Cd and Ni were the most sensitive to interferences. The effects of hydrochloric, nitric, perchloric and hydrofluoric acids were tested; perchloric acid was found to interfere most during the determinations. Hydrofluoric acid must be eliminated by evaporation. Techniques for reducing chemical interferences were evaluated. The best method was found to be matrix modification with ammonium dihydrogenphosphate and ascorbic acid for the determination of lead and nickel, and rapid heating (Max Power) for the determination of cadmium. Determinants of copper and chromium were less prone to interference.     

Account of Matrix Effects in the Spectrometric Determination of Trace Elements Using the Single-Point Standard Addition Method

Journal of Analytical Chemistry - Possibilities of taking into account matrix effects in the determination of trace elements by electrothermal atomic absorption spectrometry and inductively coupled...     

Determination of lead in plants in controlling phytoremediation processes using slurry sampling electrothermal atomic absorption spectrometry

The comparative determination of lead in plant samples by two atomic spectrometric techniques is reported. At first, slurry sampling electrothermal atomisation atomic absorption spectrometry (ETAAS) was applied. The results obtained were compared with those found after a wet digestion procedure by flame atomic absorption spectrometry (FAAS) or ETAAS. The accuracy of the studied methods was checked using a certified reference material (CL???1 CRM, Cabbage Leaves). The recovery of lead was 90% for slurry sampling ETAAS, and 86.6% for liquid sampling ETAAS. The advantages of the slurry sampling ETAAS method are the simplicity of sample preparation and very good sensitivity.     

Determination of gold and palladium in rocks and ores by atomic absorption spectrometry using two-stage probe atomization

The efficiency of two-stage probe atomization for the determination of gold and palladium in geological samples by electrothermal atomic absorption spectrometry is studied. The effects of temperature–time program and the position of the probe in an atomizer on the fractionation of sample components and the magnitude of the analytical signal are studied. It is demonstrated that gold and palladium can be quantitatively determined by atomic absorption spectrometry in rocks and ores, using a two-stage probe atomization with the limits of detection for gold and palladium 0.01 and 0.04 g/t, respectively.