湿法消解-火焰原子吸收分光光度法测定煤中七种元素含量

煤中常量和微量元素是评价煤炭质量的重要指标之一.为了确定一种可操作性强的火焰原子吸收测定煤中常量及微量元素的方法,研究了硝酸-高氯酸湿法消解煤样,火焰法测定煤样中K、Na、Ca、Mg、Zn、Cu、Fe的最佳条件.实验证明,取样量0.01～0.05 g,140℃湿法消解煤样,火焰原子吸收测定煤样中K、Na、Ca、Mg、Zn、Cu、Fe七种元素的含量准确性高,重复性好,方法简便;适合实验室分析测试,消耗少用时短,操作性强,可供相关测试单位参考.     

Selective Separation and Preconcentration of Fe(III) and Zn(II) Ions by Solvent Extraction Using a New Triketone Reagent

A simple, rapid, and accurate method was developed for separation and preconcentration of trace levels of iron(III) and zinc(II) ions in environmental samples. Methyl‐2‐(4‐methoxy‐benzoyl)‐3‐(4‐methoxyphenyl)‐3‐oxopropanoylcarbamate (MMPC) has been proposed as a new complexing agent for Fe(III) and Zn(II) ions using solvent extraction prior to their determination by flame atomic absorption spectrometry (FAAS). Fe(III) and Zn(II) ions can be selectively separated from Fe(II), Pb(II), Co(II), Cu(II), Mn(II), Cr(III), Ni(II), Cd(II), Ag(I), Au(III), Pd(II), Cr(VI), and Al(III) ions in the solution by using the MMPC reagent. The analytical parameters such as pH, sample volume, shaking time, amount of MMPC reagent, volume of methyl isobutyl ketone (MIBK), effect of ionic strength, and type of back extractant were investigated. The recovery values for Fe(III) and Zn(II) ions were greater than 95% and the detection limits for Fe(III) and Zn(II) ions were 0.26 and 0.32 µg L^?1, respectively. The precision of the method as the relative standard deviation changed between 1.8 and 2.1%. Calibration curves have a determination coefficient (r²) of at least 0.997 or higher. The preconcentration factor was found to be 100. Accuracy of the method was checked by analyzing of a certified reference material and spiked samples. The developed method was applied to several matrices such as water, hair, and food samples.     

Separation and Preconcentration of Cobalt Using a New Schiff Base Derivative on Amberlite XAD‐7

In this study, a new solid‐phase extraction procedure has been developed for preconcentration and determination of Co ions in different water samples by flame atomic absorption spectrometry (FAAS). Cobalt was preconcentrated as N,N′‐bis(pyridine‐2‐yl‐methyl)benzene‐1,4‐diamine (Co‐BPMBDA) from sample solutions using a column containing Amberlite XAD‐7 and was determined. In order to achieve the best performance for the method, effects of several parameters such as pH, concentrations of ligand, sample flow rate, eluent, and matrix ions on the method efficiency were investigated. Under optimum conditions, the preconcentration factor was found to be 200 for 1000 mL waters samples. Detection limit based on the 3S_b criterion was calculated as 0.24 µg/L for 100 mL of sample solution and relative standard deviation was found to be 1.8%. The method was applied to determine the trace amounts of cobalt in water samples.     

测定煤矿区土壤中元素含量的火焰原子吸收法

火焰原子吸收法虽已应用于各个行业领域,但该法存在样品称样量大、加酸后消解时间长、实验干扰较多等问题,其实际应用受到局限。针对这一情况,考虑到煤矿区土壤样品的特点,经过反复摸索,建立了用火焰原子吸收分光光度计测定硝酸-高氯酸消解后的土壤样品中Zn、Cu、Fe、Mg、Ca、K和Na 7种元素含量的新方法。该方法简单、快速,灵敏度和准确度较高,相对标准偏差在2.9%以下,加标回收率在97.3%~112.5%,并应用于淮南煤矿区土壤样品,取得了令人满意的效果。      

火焰原子吸收光谱法测定精铟中铅

精铟试样用HCl溶解，在稀HCl介质中，利用氘灯扣背景，消除基体的干扰。使用空气-乙炔火焰，于原子吸收光谱仪波长283．3nm处测定铅，测定范围为0．001％-0．005％，加标回收率为97．8％～103％，相对标准偏差RSD（n=7）≤5％。与其他方法对照，结果相符。