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661.
A simple and highly selective flow injection (FI) on-line preconcentration and separation flame atomic absorption spectrometric (FAAS) method was developed for the determinations of trace amounts of silver, gold and palladium. The selective preconcentration of the noble metals was achieved in a wide range of sample acidity (0.1-6 M HNO3 or HCl) on a microcolumn packed with amidinothioureido-silica gel (ATuSG). The analytes retained on the column were effectively eluted with 5.0% thiourea solution. The analytical procedure was optimized for sample acidity, elution, interferences, flow rate of sampling and eluting, and concentration of sample. Common co-existing cations and anions did not interfere with the preconcentration and determination of the three metals. At a sample loading flow rate of 4.5 ml min−1 with 60 s preconcentration, detection limits (3σ) of 1.1 ng ml−1 Ag, 13 ng ml−1 Au and 17 ng ml−1 Pd were obtained. The precisions (R.S.D., n=11) were 1.2% for Ag, 1.2% for Au and 1.7% for Pd, respectively. The detection limits can be further improved by increasing sample volume. The analytical results obtained by the proposed method for a number of standard reference materials were in good agreement with the certified values.  相似文献   
662.
应用1-(2-吡啶偶氮)-2-萘酚(简写作PAN)-镍(Ⅱ)共沉淀体系,以锰(Ⅱ)为内标,在pH 9的氨性缓冲溶液中对食盐中痕量铅(Ⅱ)进行快速共沉淀富集,并用火焰原子吸收光谱法测定铅的含量,对共沉淀条件作了优选。在优化的条件下,试液中作为内标的锰(Ⅱ)及铅(Ⅲ)离子均定量地与PAN-Ni(Ⅱ)共沉淀析出。锰(Ⅱ)、铅(Ⅱ)及镍(Ⅱ)均匀地存在于沉淀中,而且在铅(Ⅱ)、锰(Ⅱ)之间或镍(Ⅱ)、锰(Ⅱ)之间存在着一定的比例关系。因此,根据共沉淀中铅(Pb1)及锰(Mn1)的吸光度APb1,AMn1的比值即可求得铅的含量(w%),原试样中铅含量(Pb0)可由下式计算:mPb0=APb1/AMn1.mMn0。试验结果表明,经过共沉淀分离,基体干扰已予消除。此方法的检出限为3.18×10-2mg.L-1。应用于3种不同来源的食盐的分析,算得铅含量测定值的RSD(n=6)均小于4.3%,回收率测得值在95.4%至101.6%之间。  相似文献   
663.
火焰原子吸收光谱法测定土壤中镉   总被引:5,自引:0,他引:5  
用HCl-HNO3-HF-HCIO4消解土样,加入四氯化碳萃取消解液中的Cd-DDTC的配合物,用HNO3-H2O2混合液反萃取。用火焰原子吸收光谱法测定反萃取的水相中镉。  相似文献   
664.
The aim of this work was to determine the concentrations of some essential and toxic elements in the muscle of ten species of commercial fish consumed in Portugal. We combined two different techniques for determination of the elements—energy-dispersive X-ray fluorescence (EDXRF) was used to quantify K, Ca, Fe, Zn, Se, Rb, and Sr and flame atomic-absorption spectrometry for analysis of Cr, Ni, Cu, Cd, Hg, and Pb. The latter technique was used because of its higher sensitivity, because these elements were not detected by EDXRF. The results obtained show a similar pattern for the trace elements. K and Ca are present at the highest concentrations in all the samples studied, from 0.6–1.3% and from 0.04–0.08%, respectively, followed by Zn, Fe, Sr, Se, and Rb. Sr is present at higher concentrations than Rb in all the species studied except meagre. Concentrations of the elements in octopus do not follow this pattern—Fe is present at a higher concentration than Zn. Low concentrations of Cr (0.66–1.5 g g–1), Ni (0.11–0.24 g g–1), Cd (0.01–0.08 g g–1), Hg (0.49–2.74 g g–1), and Pb (0.02–0.06 g g–1) were observed in all the samples analysed. The concentration of Hg was highest in Helicolenus dactylopterus—5.4 g g–1 in one sample.  相似文献   
665.
采用微波消解,火焰原子吸收分光光度计对两个甜杨桃品种进行了微量元素的测定。试验结果表明,杨桃中钙、镁、锰、锌、铁等微量元素含量丰富,比较发现同一元素在不同品种的杨桃中无显著的区别。方法简便、快速、准确。  相似文献   
666.
脉冲进样火焰原子吸收光谱法测定血清、脑和骨中的铁   总被引:1,自引:0,他引:1  
采用脉冲微量进样火焰原子吸收光谱法测定血清、脑组织及骨中铁含量。血清样品经稀释后直接测定,脑组织及骨样品采用HNO3-HClO4湿法消化。实验探讨了进样体积、提升速度等影响因素,方法的相对标准偏差为1.1%-3.3%,平均回收率为99.0%-100.1%。  相似文献   
667.
This study presents a new procedure for the determination of trace levels of copper(II) in an aqueous matrix, through flow injection (FI) on-line preconcentration with a minicolumn packed with silica gel modified with 3(1-imidazolyl)propyl groups. After the preconcentration stage, the analyte was eluted with a HNO3 solution and determined by flame atomic absorption spectrometry (FAAS). The measurements of the analytical signals were carried out as peak area and peak height with the objective of evaluating the most appropriate absorption measurement for the proposed method. Four procedures to calculate the experimental enrichment factor (EF) were also studied. For a preconcentration time of 90 s the enrichment factors found in this study varied between 19.5-25.8 and 36.2-42.2 for peak area and peak height, respectively. The precision of the proposed method was calculated for a solution containing 20 μg l−1 of Cu(II), when 11.2 ml of solution was preconcentrated (n=7), and their respective relative standard deviation (R.S.D.) values were 1.2 and 1.4% for peak area and peak height, respectively. The detection limits obtained were 0.4 and 0.2 μg l−1 of Cu(II) for peak area and peak height, respectively, with a preconcentration time of 90 s. The on-line preconcentration system accuracy was evaluated through a recovery test on the aqueous samples and analysis of a certified material.  相似文献   
668.
A membrane filtration procedure for the preconcentration and atomic absorption spectrometric determination of Pb(II), Co(II) and Fe(III) ions in natural water samples has been established. Cellulose nitrate membrane filters (0.45 μm and 47 mm diameter) were used in all experiments. The procedure is based on chelate formation of the analyte metals with 1‐(2‐pyridylazo) 2‐naphtol (PAN) and on retention of the chelates on cellulose nitrate membrane filter. The cellulose nitrate membrane and analyte ions were completely dissolved by 500 μL of nitric acid at 85 °C on a hood and then metal determinations were performed by flame atomic absorption spectrometry. The method was applied to natural water samples for the determination of analyte ions with satisfactory results, e.g., recoveries > 95%, RSD's < 10%.  相似文献   
669.
火焰原子吸收光谱测定XF—120膦羧酸缓蚀阻垢剂中的钴   总被引:2,自引:0,他引:2  
本文研究了XF-210膦羧酸缓蚀阻垢剂中微量金属元素的火焰原子吸收光分光光度法的测定,方法简便,省时,具有良好的精密度和准确度,平均相对标准偏差为1.42%,平均回收率为95.7%。  相似文献   
670.
火焰原子吸收法测定强化食品(奶粉等)中Zn的含量   总被引:1,自引:0,他引:1  
采用干法灰化溶解样品,火焰原子吸收法测定强化食品如奶粉、米粉、黑麻糊,豆奶粉中Zn元素含量,试验结果表明此法简便、快速、准确,回收率为94%-107%。  相似文献   
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