A novel preconcentration procedure using cloud point extraction for determination of lead,cobalt and copper in water and food samples using flame atomic absorption spectrometry

In this work, a new cloud point extraction (CPE) procedure was developed for the separation and preconcentration of lead(II), cobalt(II), and copper(II) in various water and food samples. Complexes of metal ions with 1-Phenylthiosemicarbazide (1-PTSC) were extracted into the surfactant-rich phase of octylphenoxypolyethoxyethanol (Triton X-114) from samples. After phase separation, the enriched analytes were determined by flame atomic absorption spectrometry (FAAS). Factors affecting cloud point extraction, such as pH, reagent and surfactant concentrations, temperature, and incubation time were evaluated and optimized. The interference effect of some cations and anions was also studied. After optimization of the CPE conditions, the preconcentration factor of 25 and the limits of detection (L.O.D.) obtained for lead(II), cobalt(II), and copper(II) based on three sigma (n = 20) were 3.42, 1.00, and 0.67 μg L⁻¹, respectively. The method presented precision (R.S.D.) between 1.7% and 4.8% (n = 7). The presented preconcentration procedure was applied to the determination of metal ions in reference standard materials (SRM 1515 Apple leaves and GBW 07605 Tea) and some real samples including tap water, spring water, sea water, canned fish, black tea, green tea, tomato sauce and honey.     

Speciation of Cr(III) and Cr(VI) in geological and water samples by ytterbium(III) hydroxide coprecipitation system and atomic absorption spectrometry

A novel coprecipitation method with ytterbium(III) hydroxide has been established for speciation of Cr(III) and Cr(VI) in geological and water samples. At pH 10, while Cr(III) was quantitatively recovered, Cr(VI) was recovered under 10% levels. Total chromium was determined reducing of Cr(VI) to Cr(III) in acidic media with KI reagent. The concentration of Cr(VI) was calculated by the concentration difference between the total chromium and Cr(III). For the quantitative recovery of Cr(III), parameters such as pH, amount of ytterbium, centrifugation time and speed, matrix effect, KI amount, and sample volume were investigated. The preconcentration factor was 30. The limit of detection was obtained as 1.1 μg/L for Cr(III). The accuracy was checked by analyte addition and analyses of standard reference materials (TMDA-54.4 Certified Reference Water, NIST 2710 Montana Soil). Method has been successfully applied to the chromium speciation for industrial waste water of leather factories located in Bor-Nigde, and also for mine and soil samples.     

Determination of some heavy metals in food and environmental samples by flame atomic absorption spectrometry after coprecipitation

A novel preconcentration procedure based coprecipitation of Cu(II), Co(II), Cd(II), Ni(II), Mn(II), Fe(III) and Pb(II) on thulium hydroxide precipitate has been presented prior to flame atomic absorption spectrometric determination of them in environmental samples. The analytical parameters that influenced the quantitative coprecipitation of analytes including amount of thulium, pH, duration time, etc. were investigated. The effects of alkali, earth alkali, and some transition metals on the recoveries were also studied. Under the optimized conditions, the detection limits (3 sigma, N = 10) for the analytes were in the range of 0.1-1.6 μg/L, respectively. The validation of the presented coprecipitation method was checked by the analysis of certified reference materials (TMDA 54.4 fortified lake water and HR-1 Humber river sediment). The proposed coprecipitation method has been successfully applied for the determination of traces of copper, cobalt, cadmium, nickel, manganese, iron and lead in food and environmental samples.     

火焰原子吸收光谱法测定甘肃省鲜卑花属植物叶中的微量元素

目的:运用火焰原子吸收光谱法直接测定了甘南地区三个不同采集地的鲜卑花属植物叶中锌(Zn)、铜(Cu)、锰(Mn)、铁(Fe)、钴(Co)、镍(Ni)、镁(Mg)七种微量元素的含量.方法:用混合酸硝化样品,采用标准曲线法测定.结果:所测定的三个不同采集地中含有的人体必需微量元素略有差异.结论:本方法简单、准确,回收率在96.8%～102.3%之间,相对标准偏差(RSD)在0.78%～2.15%之间,结果令人满意.     

火焰原子吸收分光光度法测定常通口服液中的微量元素铁

目的测定中药常通口服液中微量元素铁的含量。方法采用火焰原子吸收分光光度法。结果Fe在10~50μg.L-1浓度范围内线性关系良好(r=0.9997),平均回收率为99.16%(RSD=2.28%,n=5)。结论方法简便、灵敏。     

Determination of Cu, Fe, Mn and Zn by flame atomic absorption spectrometry in multivitamin/multimineral dosage forms or tablets after an acidic extraction

This work presents the development of a methodology for the determination of Cu, Fe, Mn and Zn in samples of multivitamin/multimineral tablets, by flame atomic absorption spectrometry (FAAS), after extraction of the analytes with diluted hydrochloric acid solution. Several parameters that could influence the extraction process such as acid extraction solution concentration and nature, mixing mode (ultrasonic or magnetic stirring), extraction time and sample composition were evaluated. The obtained results showed that Fe, Mn and Zn were easily extracted with 1 mol/L HCl solution after 5 min of mixing with either ultrasonic or magnetic stirring for all studied samples. On the other hand, Cu extraction appeared to be more complex since it could only be extracted at the same conditions for silicate-free samples. For samples containing silicates the time of contact between solid sample and extraction solution presented remarkable influence, being necessary up to 12 h to achieve quantitative recovery with 1 mol/L HCl solution. The developed methodology was applied in the determination of Cu, Fe, Mn and Zn in seven commercially available multivitamin/multimineral tablets. The results obtained with the developed method were compared with those obtained after total digestion of samples using a closed-vessel microwave oven device.     

Chromium and iron determinations in food and herbal plant samples by atomic absorption spectrometry after solid phase extraction on single-walled carbon nanotubes (SWCNTs) disk

A preconcentration–separation procedure has been established based on solid phase extraction of Fe(III) and Cr(III) on single-walled carbon nanotubes (SWCNTs) disk. The analyte ions were quantitatively recovered at pH 8.0 on single-walled carbon nanotubes disk that contains 30 mg of nanotube. The influences of matrix components were tolerable. The detection limits for iron and chromium were calculated as 2.12 and 4.08 μg/l, respectively. The presented method was validated by the analysis of lichen (IAEA-336), CRM025-050 Metals on soil and BCR-032 Moroccan Phosphate rock certified reference materials. The method was successfully applied to the preconcentration and separation of iron and chromium in some food and herbal plant samples from Turkey.     

原子吸收分光光度法测定肾骨颗粒中钙的含量

目的:建立肾骨颗粒中钙的含量测定的方法,为其质量评价提供理论依据。方法:采用原子吸收分光光度法对肾骨颗粒中的钙的含量进行测定,并将结果与化学滴定法进行比较。结果:该方法线性、精密度、准确度、范围、耐用性均良好,钙高、中、低含量的加样回收率分别为100.20%,99.14%,99.62%(n=9)。结论:该方法灵敏快速,准确可靠,可用于肾骨颗粒中钙含量的测定。     

A rapid method for the determination of Pb, Cu and Sn in dried tomato sauces with solid sampling electrothermal atomic absorption spectrometry

In this work, lead, copper and tin were determined in tomato sauces by solid sampling graphite furnace atomic absorption spectrometry (SS-GFAAS) and the results were compared with those obtained after sample digestion. The tomato sauce samples were dried at 90 °C for 12 h and directly introduced into the graphite furnace by means of solid auto sampler. Alternatively the dried samples were digested with concentrated HNO₃ (65%) and pipetted into the graphite furnace. After the optimization of the experimental parameters, the average lead, copper and tin concentrations found by the solid sampling and digestion methods in 10 different kinds of tomato sauce samples were not significantly different at 95% confidence level. For solid sampling technique, the limits of detection (LOD) for Cu, Sn and Pb were 10.4, 3.2 and 0.4 ng/g, respectively. Whereas for digestion method, for Cu, Sn and Pb were 6.7, 2.7 and 0.3 ng/g, respectively. The proposed solid sampling technique was fast, simple, the risks of contamination and analyte loss were low.     

Simultaneous coprecipitation of lead, cobalt, copper, cadmium, iron and nickel in food samples with zirconium(IV) hydroxide prior to their flame atomic absorption spectrometric determination

A simple and new coprecipitation procedure is developed for the determination of trace quantities of heavy metals (lead, cobalt, copper, cadmium, iron and nickel) in natural water and food samples. Analyte ions were coprecipitated by using zirconium(IV) hydroxide. The determination of metal levels was performed by flame atomic absorption spectrometry (FAAS). The influences of analytical parameters including pH, amount of zirconium(IV), sample volume, etc. were investigated on the recoveries of analyte ions. The effects of possible matrix ions were also examined. The recoveries of the analyte ions were in the range of 95–100%. Preconcentration factor was calculated as 25. The detection limits for the analyte ions based on 3 sigma (n = 21) were in the range of 0.27–2.50 μg L⁻¹. Relative standard deviation was found to be lower than 8%. The validation of the presented coprecipitation procedure was performed by the analysis certified reference materials (GBW 07605 Tea and LGC 6010 Hard drinking water). The procedure was successfully applied to natural waters and food samples like coffee, fish, tobacco, black and green tea.     

原子吸收法测定葡萄酒中铅、镉、铜

目的 分析葡萄酒中金属元素的水平。方法 以3大国产品牌(张裕、王朝、长城)的26种葡萄酒为样品,经微波消解后,采用原子吸收光谱法测量了其中铅(Pb)、镉(Cd)、铜(Cu)3种重金属元素的量。结果 对于所测元素,标准曲线的相关系数均为r>0.999 5,Pb的检测限为0.006mg/L,Cd的检测限为0.029 μg/L,Cu的检测限为0.014 mg/L,各元素RSD均在0~9%之间,加样回收率91.78%~109.8%。26种葡萄酒中Pb、Cd、Cu 3种元素的平均质量浓度分别为35.357 μg/L、3.974 μg/L、0.684 mg/L。结论 该方法快速准确、灵敏度高,操作简单,分析速度快,为这3种元素在葡萄酒中的含量测定提供参考。26种葡萄酒样品中3种重金属元素的量均未超标。     

Mercury(II) and methyl mercury determinations in water and fish samples by using solid phase extraction and cold vapour atomic absorption spectrometry combination

A method has been developed for mercury(II) and methyl mercury speciation on Staphylococcus aureus loaded Dowex Optipore V-493 micro-column in the presented work, by using cold vapour atomic absorption spectrometry. Selective and sequential elution with 0.1 mol L⁻¹ HCl for methyl mercury and 2 mol L⁻¹ HCl for mercury(II) were performed at the pH range of 2–6. Optimal analytical conditions including pH, amounts of biosorbent, sample volumes were investigated. The detection limits of the analytes were 2.5 ng L⁻¹ for Hg(II) and 1.7 ng L⁻¹ for methyl mercury. The capacity of biosorbent for mercury(II) and methyl mercury was 6.5 and 5.4 mg g⁻¹, respectively. The validation of the presented procedure is performed by the analysis of standard reference material. The speciation procedure established was successfully applied to the speciation of mercury(II) and methyl mercury in natural water and microwave digested fish samples.     

原子吸收分光光度法测定桃花散中朱砂与石膏的含量

目的：建立测定桃花散中朱砂、石膏的含量测定方法。方法：湿法消解样品,采用原子吸收分光光度法测定汞和钙含量后换算。结果：加样回收率为（９９８±２０）％和（９９６±２２）％。结论：本法操作简便,结果准确精密。可用于桃花散的定量标准。     

火焰原子吸收法测定可乐宝林片中锌的含量

目的:建立可乐宝林片中锌含量的测定方法。方法:供试品加盐酸超声处理,采用火焰原子吸收分光光度法测定。结果:该方法的线性、精密度、准确度等均良好,锌的线性良好(r=0.999 8),平均回收率为97.6%(RSD为1.17%)(n=9)。结论:本方法灵敏度高、准确可靠,可作为可乐宝林片中锌的含量测定方法。     

石墨炉原子吸收分光光度法测定大鼠血浆和尿液中的赛特铂

目的建立大鼠血浆和尿液中赛特铂含量测定的无火焰石墨炉原子吸收分光光度法。方法采用岛津AA-670原子吸收分光光度仪及GFA-4A石墨炉,上海电光KY-1铂空心阴极灯,检测波长265.9 nm,测定大鼠血浆和尿液中的赛特铂含量。血尿样品用Triton X-100稀释,进样50μL。结果在浓度范围0.25 mg.L-1~10.0 mg.L-1内,样品峰面积与浓度呈良好线性关系,相关系数r2分别为血浆0.9952,尿液0.9878;加样回收率为血浆89%~112%,尿液82%~100%。结论方法简便可靠,适于生物样本中的赛特铂含量测定和动物药动学研究。     

石墨炉原子吸收分光光度法测定大鼠血浆和尿液中的赛特铂

OBJECTIVE To develop a rapid,accurate and sensitive method for the measurements of satraplatin in biological fluids of rats.METHODS Satraplatin in plasma and urine was analyzed by flameless atomic absorption spectrometry on an instrument Shimadzu AA-670 a     

火焰原子吸收分光光度法测定铋镁豆寇片中铋、镁的含量

目的 建立一种用火焰原子吸收分光光度法测定铋镁豆寇片中铋、镁含量的方法.方法 样品经硝酸处理后,用纯水制备供试品溶液,将供试品溶液喷入乙炔-空气火焰,用标准曲线法测定铋、镁的含量.结果 铋在4.0～20.0μg·mL-1范围内,线性关系良好,相关系数r=0.9998;镁在0.08～0.40μg·mL-1范围内,线性关系良好,相关系数r=0.9998.在标示量的80%,100%,120%3个浓度测定回收率,铋、镁的平均回收率分别为100.6%、100.3%,RSD分别为1.1%、0.6%(n=9).结论 本法简单,快速,准确,重现性好,适用于铋镁豆寇片中铋、镁含量的测定.     

石墨炉原子吸收光谱法测定糖尿病患者血清中微量锰和铬

本文采用石墨炉原子吸收光谱法测定糖尿病患者血清中微量锰和铬。测定条件:锰波长为279.5nm,狭缝1.9(?),灯电流6mA,干燥150℃/30s,灰化1000℃/20s,原子化2200℃/4s。铬波长为357.9nm,狭缝3.8(?),灯电流6mA,干燥150℃/30s,灰化500℃/20s,原子化2500℃/4s。方法的回收率、灵敏度和CV%:锰为105.0%,0.77PPb,6.5%。铬为96.8%,0.30ppb,4.5%。     

Determination of Pb (Lead), Cd (Cadmium), Cr (Chromium), Cu (Copper), and Ni (Nickel) in Chinese tea with high-resolution continuum source graphite furnace atomic absorption spectrometry

The contents of lead, cadmium, chromium, copper, and nickel were determined in 25 tea samples from China, including green, yellow, white, oolong, black, Pu’er, and jasmine tea products, using high-resolution continuum source graphite furnace atomic absorption spectrometry. The methods used for sample preparation, digestion, and quantificational analysis were established, generating satisfactory analytical precisions (represented by relative standard deviations ranging from 0.6% to 2.5%) and recoveries (98.91–101.32%). The lead contents in tea leaves were 0.48–10.57 mg/kg, and 80% of these values were below the maximum values stated by the guidelines in China. The contents of cadmium and chromium ranged from 0.01 mg/kg to 0.39 mg/kg and from 0.27 mg/kg to 2.45 mg/kg, respectively, remaining in compliance with the limits stipulated by China’s Ministry of Agriculture. The copper contents were 7.73–63.71 mg/kg; only 64% of these values complied with the standards stipulated by the Ministry of Agriculture. The nickel contents ranged from 2.70 mg/kg to 13.41 mg/kg. Consequently, more attention must be paid to the risks of heavy metal contamination in tea. The quantitative method established in this work lays a foundation for preventing heavy metal toxicity in human from drinking tea and will help establish regulations to control the contents of heavy metals in tea.     

Superiority of nitric acid for deproteinization in the determination of trace lithium in serum by graphite furnace atomic absorption spectrometry

Physiological level of trace lithium in human serum was determined by graphite furnace atomic absorption spectrometry (GFAAS). 3.5% HNO₃ (v/v) was employed as a protein precipitant for sample treatment and at the same time verified as a very effective chemical modifier to eliminate the interference of chloride. The analytical conditions for lithium determination in serum were investigated and the optimal pyrolysis and atomization temperatures were 800 °C and 2700 °C. The accuracy and precision of the method were tested by determining lithium in a RANDOX HN1530 assayed human multi-sera and a pooled human serum. The result was in good agreement with the target value and CV of the pooled human serum was 4.74% (n = 10). The characteristic mass, the limit of detection (LOD) of the proposed method were 0.8 pg and 0.01 μmol/L, respectively. Median ± S.E.M. of serum lithium in 220 Chinese people was 0.25 ± 0.02 μmol/L.