Flow-injection spectrophotometric multidetermination of metallic ions with a single reagent exploiting multicommutation and multidetection

A flow system designed by computer-controlled discrete commutation devices is proposed for the multidetermination of metallic ions with a single chromogenic reagent. Intermittent addition of masking agents and changes of the reaction pH were exploited to implement selective determination of four species. Multidetection with an optical-fiber CCD-array spectrophotometer enabled simultaneous measurements at different wavelengths for multidetermination. The proposed system was applied to the determination of iron, copper, nickel and zinc in alloys and pharmaceutical preparations, yielding results in agreement with those obtained by flame atomic absorption spectrophotometry at the 95% confidence level. The sampling rate was estimated to be 80 determinations per hour. Coefficients of variation lower than 2% (n = 20) were achieved for all species. Received: 25 October 2000 / Revised: 19 December 2000 / Accepted: 31 December 2000     

Flow-injection spectrophotometric multidetermination of metallic ions with a single reagent exploiting multicommutation and multidetection

A flow system designed by computer-controlled discrete commutation devices is proposed for the multidetermination of metallic ions with a single chromogenic reagent. Intermittent addition of masking agents and changes of the reaction pH were exploited to implement selective determination of four species. Multidetection with an optical-fiber CCD-array spectrophotometer enabled simultaneous measurements at different wavelengths for multidetermination. The proposed system was applied to the determination of iron, copper, nickel and zinc in alloys and pharmaceutical preparations, yielding results in agreement with those obtained by flame atomic absorption spectrophotometry at the 95% confidence level. The sampling rate was estimated to be 80 determinations per hour. Coefficients of variation lower than 2% (n = 20) were achieved for all species.     

Comparison of slurry sampling and microwave-assisted digestion for calcium, magnesium, iron, copper and zinc determination in fish tissue samples by flame atomic absorption spectrometry

The development of a slurry sampling method for the determination of calcium, copper, iron, magnesium and zinc in fish tissue samples by flame atomic absorption spectrometry is described. In comparison with microwave-assisted digestion, the proposed method is simple, requires short time and eliminates total sample dissolution before analysis. Suspension medium was optimized for each analyte to obtain quantitative recoveries from fish tissue samples without matrix interferences. Nevertheless, iron recoveries higher than 46% were not found. Treatment of samples slurried in nitric acid by microwave irradiation for 15-30 s at 75-285 W permitted to achieve efficient recoveries for calcium, iron, magnesium and zinc. Further improvement in the matrix effects for iron determination was accomplished by the use of an additional step of short microwave-assisted suspension treatment. However, standard addition method was required for calcium and copper determination, being necessary hydrochloric acid as suspension medium for the last one. Although copper could not be determined in the certified reference material using microwave-assisted digestion, the accuracy of the slurry sampling method was verified for all the investigated analytes. Detection limits were 22.8 ± 8.0, 0.884 ± 0.092, 5.07 ± 0.76, 35.5 ± 0.7 and 1.17 ± 0.04 μg g⁻¹ for calcium, copper, iron, magnesium and zinc, respectively. The standard deviations obtained using slurry sampling method and microwave-assisted digestion were not significantly different, and the mean relative standard deviation of the over-all method (n = 3) of the slurry sampling method for different concentration levels was below 12%.     

Direct determination of calcium,copper, iron,magnesium, manganese and zinc in amniotic fluid samples using inductively coupled plasma-atomic emission spectrometry

An inductively coupled plasma-atomic emission spectrometric method is reported for the determination of calcium, copper, iron, manganese, magnesium and zinc. Samples are introduced directly when a sheath gas device is used. An external calibration procedure is used. The standards are prepared in a matrix composed of 0.5% (w/v) albumin and 0.76% (w/v) sodium chloride. The procedure was evaluated with a standard reference material (NBS SRM 909 Human Serum); all the values obtained are in agreement with the certified values. Results obtained for the determination of zinc, calcium, magnesium, copper, iron and manganese in amniotic fluid samples are reported.     

甘肃省裕固族地区部分7～13岁儿童智商与血清钙、镁、铁、锌、铜含量的相关分析

为了解甘肃省裕固族地区儿童智商发育及血清钙、镁、铁、锌、铜水平,收集可能影响儿童智力发育的资料,给相关研究提供科学依据,采用整群随机抽样的方法,抽取甘肃省张掖市肃南裕固族自治县的部分7~13岁儿童作为研究对象,自行设计问卷收集儿童信息、现场采用瑞文智力测试图谱对研究对象进行了智力测试,同时采集部分儿童指端末梢血,用原子吸收光谱仪测定了血钙、镁、铁、锌、铜水平,并做了相关性分析。结果表明,智商均值为(106.26±14.10)分,接近人群中等水平(90~109分);按年龄、民族和城乡出生地分组,13~14岁组与其他各年龄组间均存在统计学差异,7~9、10~12岁组内未发现统计学差异,组间存在部分统计学差异;非裕固族、城市儿童智商值高于裕固族、农村儿童,差异有统计学意义。全血5种元素测定结果:钙、镁、铁、锌、铜元素平均水平分别为:(2.02±0.58)mmol/L、(1.69±0.39)mmol/L、(8.67±2.01)mmol/L、(91.51±29.23)μmol/L、(17.05±6.13)μmol/L,均处于人群正常水平;各年龄组间比较,钙、锌、镁显示出统计学差异,其他元素及组间对比,均无统计学意义;按农村与城镇、裕固族与非裕固族分类,钙、镁、铁、锌、铜元素水平均未发现统计学差异;进一步按照智力等级进行相关性分析,显示锌的差别有统计学意义。提示与全国儿童智力发育水平相比,裕固族地区儿童IQ及血清钙、镁、铁、锌、铜元素平均水平接近人群正常水平,但智力与锌摄入水平存在统计学相关;城乡等社会因素与裕固族地区儿童智力相关性更大。     

孕妇微量元素的调查分析

目的 了解目前天津地区妊娠期妇女微量元素缺乏情况,为孕妇合理补充微量元素提供临床指导.方法 采用原子吸收光谱法对孕妇全血进行铜,锌,钙,镁,铁等5种微量元素检测,并对结果进行统计分析.结果 妊娠期妇女铜,锌,钙,镁,铁等5种微量元素缺乏率分别为13.2％、38.6％、26.2％、12.4％、23％.结论 加强妊娠妇女钙、铁、锌的合理补充,以保证母体健康和胎儿正常发育.     

沈阳市学龄前儿童末梢血矿物质检测结果分析

为了解沈阳市学龄前儿童体内矿物质钙、铁、锌、铜、镁的含量与年龄和性别的关系,探讨防治其缺乏的综合措施,利用BH 5100型原子吸收光谱仪对3483例学龄前儿童末梢血中铜、锌、钙、镁和铁元素进行了检测,采用SPSS 17．0软件进行统计分析。结果表明,该地区学龄前4个不同年龄组儿童末梢血锌、钙、铁、铜元素缺乏严重,分别占总样本的66．90％、39．76％、32．5％和26．87％;3～岁组末梢血中钙、铁、锌、镁含量与其它年龄组比较差异有统计学意义（P〈0．05）,各元素在性别问差异无统计学意义（P〉0．05）。该地区学龄前儿童钙、铁、锌、铜失衡明显,应加强营养素的合理搭配及矿物质的补充,保证儿童的健康成长。     

367名幼儿智力发育与血中五种元素相关性分析

为探讨血铜、锌、钙、镁、铁5种元素对儿童智力的影响及其相关性,采用首都儿科研究所编制的0—6岁儿童神经心理发育量表,对367名2—4岁儿童进行现场智力测试并对抚养人进行问卷调查;采集其指尖末梢血,运用原子吸收光谱仪检测了儿童血铜、锌、钙、镁、铁5种元素含量。结果表明,调查对象血铜、锌、钙、镁、铁5种元素低下,检出率分别为25．1％、76．6％、5．7％、1．4％、37．1％,城乡儿童全血铜、锌、钙存在明显差异（P〈0．05）;儿童智力低下检出率为2．4％,儿童智能发育与其年龄、母亲文化水平、是否接受学前教育、血锌、铁呈正相关,与血钙、铜呈负相关。提示该地区2—4岁儿童血铜、锌、铁低下检出率较高,智能发育总体较为合理,但受血铜、锌、铁等多种因素影响,提高父母文化素质,加强儿童早期教育及营养有助于促进儿童智能发育。     

西安市老年人末梢血铜、锌、铁、镁、钙元素含量分析

为调查60岁以上老年人体内微量元素及钙、镁的含量,采用原子吸收光谱法对西安市60岁以上的老年人末梢血中的铜、锌、铁、镁、钙的含量进行了测定,观察了5元素的缺乏率及随年龄的增长5元素的缺乏情况.结果表明,60岁以上老年人,元素过量的情况鲜见;铜、锌、铁、镁、钙的缺乏率分别为37.87%0,11.76%,21.51%,2....     

火焰原子吸收法测定竹荪中的微量元素

使用灰化法处理样品,火焰原子吸收光谱法测定了竹荪中的钾、钙、钠、镁、铁、锰、铜、锌的含量。结果显示,竹荪中含有丰富的铁、锰、铜、锌4种人体必需微量元素。加标回收率为93.2%~103.2%,该法测定快速、简单,结果满意。     

Atomic absorption spectrometric determination of calcium and other metallic elements in some animal protein sources

The phosphorus content of some animal protein sources was determined in order to identify the sample with the highest phosphorus content for use as a pilot sample. Varying concentrations of strontium and lanthanum were added to solutions of the ashed pilot sample for the determination of calcium and magnesium using flame atomic absorption spectrophotometry operated on the air-acetylene mode. At least 3000 ppm of strontium or lanthanum was required to completely overcome the interference of phosphate ion, PO(4)(3-), and give peak values for calcium. The presence of strontium or lanthanum did not affect the amount of magnesium obtained from the analyses. Based on this, a procedure is proposed and the results obtained by this procedure for calcium are more enhanced than those obtained without the addition of strontium or lanthanum for the same samples whereas comparable results were obtained for all other elements whether strontium or lanthanum was added or not. The method gives more accurate results and is reproducible. The coefficients of variation calculated using one of the samples were 0.58% for magnesium, 3.12% for zinc; 0.44% for calcium, 11.06% for lead, 22.22% for nickel, 3.53% for manganese and 3.50% for iron at the concentration levels found in that sample. Recoveries of spiked calcium, magnesium and zinc were quantitative. Also, for selected elements, results from the procedure compared well with those from chemical analysis.     

Differentiation of Spanish brandies according to their metal content

Eleven metals, namely, aluminium, calcium, cadmium, copper, iron, lead, magnesium, manganese, potassium, sodium and zinc were determined in twenty samples of Sherry brandies and twelve samples of Penedés brandies by applying atomic spectrometry techniques. Flame atomic absorption spectrometry was used for quantitating calcium, copper, iron, magnesium, manganese and zinc; atomic emission spectrometry to determine potassium and sodium; and graphite furnace atomic absorption spectrometry to analyse aluminium, cadmium and lead. A chemometric approach was followed to study the discrimination between brandies from Sherry or Penedés according to the metal profile.     

The optimization of an ICP injection technique and the application to the direct analysis of small-volume serum samples

The optimization and the analytical properties of an injection technique for the analysis of small-volume samples (50–200 μl) by inductively coupled plasma atomic emission spectroscopy (ICP-AES) are described. Samples are injected into a small funnel connected to a concentric glass nebulizer. A 3 kW argon/nitrogen ICP with power stabilization is used as excitation source. When operating the nebulizer at an argon pressure of 5 bar, relative detection limits for calcium, copper, iron, magnesium and zinc (0.2–50 $\text{ng}\text{ml}$) are a factor of 2 to 10 higher when compared with ICP methods using continuous nebulization. However, the full power of detection of the injection method is obtained at a 50 μl sampling volume. Matrix effects caused by sodium salt concentrations of 5 $\text{g}\text{l}$ are lower than 10%. Relative standard deviations s_r,(I_X) ranged from 0.03 to 0.07. The method was applied to the sequential determination of trace elements (copper, iron and magnesium) in human serum samples after a 1 + 4 dilution with Herrmann solution. The accuracy of the method is illustrated by the analysis results for calcium, copper, iron, magnesium and zinc in a series of test serum samples.     

Identical flow injection spectrophotometric manifold for determination of protein, phosphorus, calcium, chloride, copper, manganese, iron, and zinc in feeds or premixes

A simple procedure using an identical manifold was developed for determination of nitrogen (protein) phosphorus, calcium, chloride, copper, manganese, iron, and zinc in feeds and feedstuffs. By changing appropriate reagents and detection wavelength, these 8 elements were determined successively with a simple identical double-line flow injection (FI) manifold. Fl spectrophotometric determinations were made by the blue indophenol reaction for ammonium, the molybdenum blue method for phosphate, the cresolphthalein complexone procedure for calcium, and the mercuric thiocyanate procedure for chloride. The chromogenic reagents for copper, iron, manganese, and zinc determination were bis(cyclohexanone)oxalydihydrazone (Cuprizone), 1,10-phenanthroline, formaldoxime, and xylenol orange, respectively. Sample digestion catalyst, Fl manifold, and some chemical parameters were optimized. The proposed procedure had a sampling rate of 90/h for each analyte. The determination ranges (mg/L) were 10-60 for N, 1-15 for P and Ca, 540 for Cl, and 0.5-15 for Cu, Fe, Mn, and Zn, respectively. Results of the analyses of animal feed and feedstuff samples by this procedure did not differ significantly from those obtained by proven manual methods.     

TRIEN and TETREN as titrants in potentiometry with a silver indicator electrode

The possibility of application of triethylenetetramine (TRIEN) and tetraethylenepentamine (TETREN) in metal titrations with the silver electrode as indicator was investigated. Copper, cadmium and zinc were determined in the presence of calcium, magnesium, aluminium and iron(III) in the concentration range from 0.02 to 2mM. The errors did not exceed 1%. On a similar basis copper and iron may be successfully determined in their mixtures under carefully controlled conditions. Copper is titrated with TRIEN, and both metals with EDTA at pH 7.5-8.0 in sulphosalicylate medium. The results obtained were in good agreement with those theoretically predicted.     

沈阳市20335名0～7岁儿童全血中五种元素含量的分析

为了解沈阳市0～7岁儿童全血铜、锌、钙、镁、铁元素缺乏情况,探讨性别、年龄与5种元素含量之间的关系,对沈阳市20335名0～7岁儿童进行末梢指间采血,用BH5100型原子吸收光谱仪测定了全血中钙、镁、铜、铁、锌的含量。结果表明,儿童血锌平均水平低于正常值范围,缺乏最严重,缺乏率为77．78％;血铜、锌、铁缺乏率与年龄有线性相关关系,且随着年龄的增加呈现下降趋势（P〈0．05）,下降速度在40％～60％之间;全血中5种元素均存在年龄差异（P〈0．01）,血铜元素男童明显高于女童（P〈0．01）。提示儿童应加强膳食干预,提高各种富含微量元素的食物摄人,以促进儿童的生长发育。     

微波消解-电感耦合等离子体原子发射光谱法同时测定工业锅炉水中的六种金属元素

应用微波消解,电感耦合等离子体原子发射光谱法同时测定锅炉水中的钙、镁、铜、铁、铝、锌六种金属元素.对射频功率、雾化气流量、分析线进行了优化.各元素校准曲线的相关系数均在0.999 5以上,检出限在0.000 7～0.006 0 mg/L之间.样品分析结果的相对标准偏差为0.48％～6.8％,加标回收率为94.0％～105％.     

1152例婴儿血中6种元素检测结果的分析

为探讨婴儿体内铜、锌、钙、镁、铁和铅微量元素的含量及其与年龄、性别的关系,测定了1 152例湖南长沙地区1岁内婴儿指末梢全血中6种元素铜、锌、钙、镁、铁和铅的含量,对其结果进行了统计分析。结果表明,所测婴儿元素铁、锌缺乏最显著,其次是钙缺乏;铜、镁无明显失衡;血铅超标的水平较低;不同性别之间6种元素含量的差异无统计学意义。提示在长沙地区的孕婴保健中,应加强锌、钙与铁的合理补充。     

Synthesis of o,o′-dihydroxyazo compounds and their application to the determination of magnesium and calcium by flow injection analysis

Seven _o,o′-dihydroxyazo dyes were synthesized and examined as spectrophotometric reagents for magnesium and calcium. These reagents are highly sensitive for magnesium (? = 47 000) and calcium (? = 39 000 l mol^?1 cm^?1). Of the reagents synthesized, 2-(2-hydroxy-3,6-disulfo-1-naphthylazo)-5-(N,N-diethylamino)phenol was the best because of its ease of preparation and purification, and its stability in alkaline solution. This dye was applied in the determination of magnesium and calcium by flow injection analysis. The total concentration of magnesium (0.1–1.2 mg 1^?1) and calcium (0.4–4.0 mg 1^?1) was determined by masking iron(III), aluminium(III), copper(II), zinc(II), manganese(II) and cadmium(II) with 2,3-dimercapto-1-propanol (DMP) and triethanolamine (TEA). Magnesium was determined by masking calcium and the other metal ions with a ligand buffer containing barium(II)—EGTA, DMP and TEA. The amount of calcium was obtained as the difference between the two peak heights. Results for the determination of magnesium and calcium in potable water and serum are presented.     

Direct determination of selenium in a wild fruit juice by electrothermal atomic absorption spectrometry

A matrix modifier composed of platinum and nickel is proposed for the determination of selenium in a wild fruit juice made from Lantingguo (Vuccinium uliginosam). Five matrix modifiers (copper/nickel, palladium/magnesium, platinum/magnesium, platinum/nickel and platinum/copper) for suppressing the interference effects of seven co-existing elements (potassium, phosphorus, calcium, magnesium, manganese, zinc and iron) in a wild juice were studied and a matrix modifier composed fro;m 10 mug of platinum and 200 mug of nickel was found to give the best performance. Selenium in three juices was determined by electrothermal atomic absorption spectrometry employing the proposed matrix modifier without matrix preseparation. The relative standard deviation was 14% for 0.20 mg l(-1) of selenium. The recoveries were 95-110%. A characteristic mass was 28 pg.