Assessment of the essential element and heavy metal content of edible fish muscle

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.     

原子吸收法测定杨桃中的微量元素

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。     

脉冲进样火焰原子吸收光谱法测定血清、脑和骨中的铁

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％。     

Application of silica gel organofunctionalized with 3(1-imidazolyl)propyl in an on-line preconcentration system for the determination of copper by FAAS

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.     

Membrane Filtration of Iron(III), Copper(II) and Lead(II) Ions as 1‐(2‐Pyridylazo) 2‐Naphtol (PAN) for Their Preconcentration and Atomic Absorption Determinations

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%.     

火焰原子吸收光谱测定XF—120膦羧酸缓蚀阻垢剂中的钴

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％。     

火焰原子吸收法测定强化食品(奶粉等)中Zn的含量

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％。     

11种补肾中成药物中4种金属元素测定分析

采用火焰原子吸收分光光度法测定了１１种临床上常用的补肾中成药物中锌、镉、钾、钠的含量。结果表明，１１种药物中与中医“肾阳虚”症关系较为密切的锌及人体必需的宏量元素钾、钠含量非常丰富，镉含量较低。探讨了药效与金属元素之间的相关性，提出了与中医临床用药相吻合的结论。     

微波消解-火焰原子吸收光谱法测定冬虫夏草中的微量元素

采用微波消解处理冬虫夏草,使用火焰原子吸收光谱法测定其6种微量元素的含量。冬虫夏草中铁、铜、锌、锰、镁、钙的含量分别为874.68,7.82,96.22,53.47,1743.91,196.80μg·g^-1。该方法加标回收率为在99.05%—102.32%之间,方法简单、快速、灵敏、准确,可为冬虫夏草的食品开发,中药的基础研究提供依据。     

火焰原子吸收光谱法测定工作场所空气中铜及化合物的不确定度评定

通过对火焰原子吸收光谱法测定工作场所中铜及化合物含量的测定过程分析,合理选择评定方法,简化并计算了测试过程中的不确定分量,计算出了相对合成不确定度和相对扩展不确定度,达到了对其测量不确定度合理评定的目的。