石墨炉原子吸收法测定补钙剂和补锌剂中痕量镉

探讨了用塞曼效应石墨炉原子吸收法测定补钙剂和补锌剂中痕量镉,研究了石墨炉升温程序及基体改进剂对测定的影响。测定结果表明,采用塞曼效应扣背景的方法,以5μL1.0g／L硝酸钯作为基体改进剂,能够提高镉对温度的稳定性和分析的灵敏度,用标准曲线法测定镉,回收率的平均值高达96％o     

累积进样石墨炉原子吸收光谱法测定地表水中痕量镉

采用累积进样石墨炉原子吸收光谱法直接测定地表水中痕量镉,并讨论了几种基体改进剂对镉测定的影响。通过采用NH4NO3 PdCl2基体改进剂,提高了镉的灰化温度和灵敏度,用于地表水中痕量镉的直接测定,获得了满意的结果。方法的检出限低、灵敏度高,具有良好的精密度和准确度,分析步骤简单。在本实验条件下,检出限为0.06 ng/mL,加标回收率在96.0%~103%之间,相对标准偏差为3.4%~7.1%(n=6)。运用该法测定了湖州笤溪水中镉的含量为0.20μg/L。     

氢化物发生-原子荧光法测定纯铜中镉

用717阴离子交换树脂填充柱选择性吸附CdCl42-阴离子,以实现其与大量铜基体的分离。在标准溶液中匹配适当基体浓度并采用氢化物发生-原子荧光法,实现了铜/镉质量比为2000~50000的纯铜中痕量镉的测定。在基体铜的浓度为50mg/L的样品消化液中,镉的检出限为0.2μg/L;精密度为3.0%(n=7,3.0μg/L),镉浓度在1.0~25.0μg/L范围内呈良好线性关系。本法适用于纯铜中痕量镉的测定。     

塞曼效应无火焰原子吸收法直接测定化探样品中痕量镉

地球化学样品中痕量镉(0.0Xppm)不经分离富集直接用无火焰原子吸收法测定是困难的。现有文献多采用分离富集后才能测定,或加入基体改进剂,我们曾在此基础上进行试验与探讨,但基体干扰仍未能消除。我们发现,用硫脲-EDTA盐-磷酸二氢铵作为基体改进剂,能消除基体干扰且提高了镉的原子化效率,无需分离富集可直接测定地球化探样品中痕量镉。用拟定的方法测定地球化学标准样中镉的结果与可用值相符,本法灵敏,快速、能满     

石墨炉原子吸收法测定食品中痕量铅、镉

本文研究了巯基棉富集分离及基体改进剂与石墨炉原子化法相结合的铅、镉连续检测法,并对几种类型的食品进行了试验。该法可准确测定多种类型食品中痕量铅、镉。一、仪器与试剂     

石墨炉原子吸收光谱法测定人参中痕量镉

本实验考察了氟化铵、磷酸二氢铵、二氯化钯、柠檬酸、酒石酸作为基体改进剂对石墨炉原子吸收直接测定人参中痕量镉的影响,结果表明氟化铵和柠檬酸二元混合物基体改进剂既能提高人参样品液中镉的热稳定性,又能降低人参的背景干扰,具有明显的基体改进作用,回收率98.0%~102.0%,相对标准偏差(RSD)1.4%~2.4%。     

石墨炉原子吸收法测定柑桔中痕量镉

镉在人体中主要对肝、肾和骨组织产生伤害。测定食品中镉含量是我国食品卫生标准所要求的。目前因为国内外一般采用吸光光度法、伏安法和原子吸收法测定食品中的镉,其中石墨炉原子吸收法因简便快速,应用较广,但该法基体干扰严重、重现性较差。笔者运用基体改进剂来消除该法用于柑桔中痕量镉测定时的干扰,探讨了基体改进剂种类、用量以及石墨炉升温程序等对测定的影响。     

CL-7301微色谱柱分离铀化合物中痕量镉的方法研究

采用CL-730l树脂微色谱柱研究了铀化合物中基体铀和痕量镉的分离条件,并用在线富集法测定了铀化合物中的痕量镉.通过试验选择0.125mol/L的HI酸介质中,镉的吸附率接近100%,而铀不被吸附,分离效率达到99.9%以上.吸附在柱上的镉用10 g/L EDTA 洗脱,原子吸收光度法测定.利用在线富集技术,镉的检出限降低至2.3μg/L.对八氧化三铀和分析纯醋酸双氧铀样品中痕量镉进行测定,方法精密度为1.5%,加标回收率为96%～98%.     

微波消解-石墨炉原子吸收光谱法测定纸质食品包装材料中的痕量镉

建立了微波消解–石墨炉原子吸收光谱法测定纸质食品包装材料中痕量镉的检验方法。样品经微波消解后,以硝酸镍为基体改进剂,试验确定了石墨炉原子吸收法测定镉的最佳仪器条件。镉的质量浓度在0～10μg/L与吸收峰面积呈良好的线性关系,线性相关系数r=0.9997,检出限为0.025μg/L。将该法用于纸质食品包装材料中痕量镉的测定,并进行加标回收试验,回收率为96.0%～105.5%,相对标准偏差不大于4.4%(n=10)。     

石墨炉原子吸收光谱法测定饲料及矿物饲料中的痕量镉

镉是对畜禽生长有害的金属元素。动物长期采食被镉污染的饲料会导致慢性镉中毒。其毒性作用除干扰铜、锌和钴等微量元素的代谢外 ,还直接抑制某些酶系统[1] 。测定食品以及饲料中镉含量是我国食品以及饲料卫生标准的要求。用ＦＡＡＳ测镉使用的基体改进剂有钯[2 ] 、ＮＨ4 Ｈ2 ＰＯ4[2 ] 和Ｐｄ +Ｍｇ(ＮＯ4 )2[3] 等。本文针对饲料样品及矿物元素饲料的镉 ,通过对基体改进剂钯和ＮＨ4 Ｈ2 ＰＯ4 在梯度浓度的条件下 ,其对应镉的吸光度和对离子的抑制情况进行比较测试 ,以便寻找一种更加适合饲料以及矿物元素饲料中痕量镉的测定的基体改进剂…     

Preconcentration and determination of cadmium by GFAAS after solid-phase extraction with synthetic zeolite.

The solid-phase extraction (SPE) method for the preconcentration of trace amounts of cadmium using synthetic zeolite A-4 and its determination by graphite furnace atomic absorption spectrometry (GFAAS) was investigated. The preconcentration conditions, such as the optimum pH range of the sample solution for the adsorption of cadmium and the kind of acid solution for dissolving the cadmium-adsorbed synthetic zeolite A-4, as well as the measurement conditions for the determination of cadmium by GFAAS, e.g., the ashing and atomizing temperature, were investigated. Quantitative recovery of cadmium onto zeolite A-4 from the sample solution over the pH range 2.0 - 9.0 was achieved by the batch method. After the solid-phase (cadmium-adsorbed zeolite A-4) was separated from the sample solution by a membrane filter, it was dissolved in 2.0 cm(3) of 2.0 mol dm(-3) nitric acid. An aliquot of the resulting solution was injected into the graphite furnace. In GFAAS measurements an alternate gas (Ar, 90%; O(2), 10%) was used as a sheath gas, and the ashing temperature and atomizing temperature were 400 degrees C and 1600 degrees C, respectively. The detection limit (3 sigma) for cadmium was 0.002 microg dm(-3). The relative standard deviation at 0.010 microg dm(-3) was 3.5 - 4.5% (n = 5). The proposed method has been successfully applied to the analysis of trace cadmium in environmental water samples.     

Determination of Cadmium in Water Samples by Zeeman Atomic Absorption Spectrometry

The toxicity and harmfulness of cadmium on environment and human being are well known. The sources of cadmium pollution include electroplating operation, smelting operation, dye, battery,and the waste from chemical industry. Graphite furnace atomic absorption spectrometry (GFAAS) was commonly recommended for the determination of Cd in water sample due to the rather low concentration. However, the matrix effects of the concomitants such as NaCl, CaCl₂ limit the analytical accuracy of Cd by GFAAS. Chemical modifiers are usually employed to overcome the matrix effects in GFAAS.     

石墨炉原子吸收光谱法测定人体指甲中痕量镉

通过对氢氧化四甲胺溶解人体指甲样品分解方法的研究，建立了石墨炉原子吸收光谱法测定指甲中痕量镉的方法，方法具有试剂用量少，空白易控制，操作方便等优点，用此法对长期从事与镉接触的工作人群与普通人群指甲中镉含量的分析对比，初步揭示指甲作为样本具有代表性，长期从事接触镉的工作会引起镉在人体中的积累。     

痕量镉测定方法的最新进展

评述了近年来国内外分析痕量镉的进展，包括分光光度法、原子吸收光谱法、电化学分析法等，并对痕量镉测定方法的发展作出阐述（引用文献87篇）。     

Comparison of carrier elements for coprecipitation and graphite-furnace atomic absorption spectrometry

The group IIIB elements (aluminum, gallium and indium) and iron(III) were studied from the standpoint of the advantageous combination of coprecipitation and graphite-furnace atomic absorption Spectrometry (GFAAS). Milligram quantities of four hydroxides were precipitated at different pH's from solutions containing traces of copper(II) and cadmium(II) ions, in order to examine the effect of pH on the coprecipitation. Almost similar results were obtained for gallium, indium and iron hydroxides, with which the copper and cadmium were coprecipitated nearly completely at pH>7. In case of aluminum hydroxide, the optimal pH range was narrow because of the redissolution of the precipitate in alkaline solutions. The removal of indium carrier was successfully achieved by volatilization as bromide at the pyrolysis stage in GFAAS, otherwise serious background absorption interfered with the trace determination. Volatilization loss of cadmium was eliminated by adding a small amount of miourea. Gallium carrier was mostly removed as chloride, but large background absorption still occurred in the determination of cadmium.     

斜坡升温平台石墨炉法直接测葡萄酒中铅

研究了石墨炉法直接测定葡萄酒中铅的测定方法,以磷酸二氢氨－硝酸镁作基体改进剂,采用多步斜坡升温,恒温平台石墨炉技术测定了四个国家８种类别的葡萄酒中微量铅,回收率９６．０％～１０３．５％,ＲＳＤ３．２％,并采用国家标准物质ＧＢＷ０８５０３小麦粉制成悬浮液,验证了方法的准确度与重现性,结果满意。     

Determination of cadmium in paint samples by graphite furnace atomic absorption spectrometry with optical temperature control

A graphite furnace atomic absorption spectrometry (GFAAS) method with optical temperature control for the determination of trace cadmium in paint samples is described. Optical temperature control was superior in many respects to current temperature control. The sensibility increased by 60%, the linear range widened by 60%, and the life of graphite tube showed a 200–300% increase because atomization temperature was lowered distinctly and atomization time was shortened. Use of lanthanum chloride as a matrix modifier was investigated. The linear range of calibration curve was 0–24 ng mL⁻¹. The detection limit was 9.6 ng L⁻¹. The characteristic mass was 3.0 pg. The method also resulted in excellent reproducibility (≤2.5% R.S.D.) at such low levels, and the recovery of added cadmium in paint samples was from 94.6% to 102%. This method is readily applicable to the determination of cadmium in paint samples.     

Solid Phase Extraction of Trace Amounts of Cadmium with Cetyltrimethylammonium Bromide‐Coated Magnetic Nanoparticles Prior to Its Determination by Flame Atomic Absorption Spectrometry

A solid‐phase extraction (SPE) method has been presented for the selective separation and preconcentration of trace amounts of cadmium using cetyltrimethylammonium bromide (CTAB)‐coated Fe₃O₄ nanoparticles (NPs). The method is based on the sorption of cadmium as CdI₄^2? complex on the positively charged surface of the CTAB‐coated Fe₃O₄ NPs. The preconcentrated cadmium is then desorbed from the surface of the sorbent and is determined by flame atomic absorption spectrometry. The influences of the experimental parameters including pH of the solutions, amount of surfactant, iodide concentration, sample volume, eluent type and volume on the recovery of the analyte ions were investigated. Under the optimum conditions by the extraction of 500 mL of aqueous samples, a preconcentration factor of 250 was achieved. The detection limit (3s) was 0.06 μg L^?1, and the relative standard deviations at 0.5 and 5 μg L^?1 levels of cadmium (n = 10) were 3.2 and 1.9% respectively. The proposed method was successfully applied to the determination of cadmium in water samples. The accuracy was evaluated through the recovery experiments and independent analysis by the graphite furnace atomic absorption spectrometry (GFAAS).     

石墨炉原子吸收光谱法测定饮料中的锗及基体干扰的研究

本实验以硝酸镍为基体改进剂，用塞曼石墨炉原子吸收法测定样品中的微量锗，研究了溶液介质与共存元素对测定的影响。方法简便，准确快速，灵敏度高。     

采用钯基体改进剂石墨炉原子吸收法测定纺织品中的可萃取铅

纺织品标准中对铅的限量极为严格,但萃取汗液基体成分复杂,背景吸收干扰强烈,为解决纺织品中的可萃取铅检测的困难,建立了一种采用基体改进剂的石墨炉原子吸收光谱法,测定纺织品中的可萃取铅。通过比较两种基体改进剂,优化实验条件,确定了以钯-硝酸镁为基体改进剂、灰化温度1 200℃、原子化温度2 300℃的实验条件。结果表明,以钯-硝酸镁为基体改进剂更能有效降低纺织品可萃取铅的基体干扰,并且具有良好的精密度(2.6%~3.3%)和准确度(加标回收率94.3%~105.6%)。