Kazi Tasneem G, Afridi Hassan I, Jamali Mohammad K, Kazi Gul H, Arain Mohammad B, Jalbani Nussrat, Sarfraz Raja A, Shar Ghulam Q
University of Sindh, Center of Excellence in Analytical Chemistry, Jamshoro, Pakistan.
J AOAC Int. 2006 Sep-Oct;89(5):1410-6.
An ultrasonic-assisted leaching procedure was developed for the determination of heavy elements (As, Cu, Cd, Pb, and Zn) in Certified Reference Material of human hair (CRM 397) provided from the Community Bureau of Reference (BCR) of the Commission of the European Community. Concentrated nitric acid-30% hydrogen peroxide (2 + 1) was used for the leaching method. The effects of different factors on acid leaching of elements, such as presonication time (without ultrasonic stirring), sonication or exposure time to ultrasound, and temperature of the ultrasonic bath have been investigated. Optimum values of these parameters were selected for the maximum extraction of heavy metals from CRM BCR 397 and human scalp hair samples of normal healthy males. To check the validity of the proposed method, a wet acid digestion method was used to obtain the total elemental concentration in CRM BCR 397 and scalp hair samples. Cu and Zn in leachate and digests were measured by flame atomic absorption spectrometry using a conventional air/acetylene flame, while As, Cd, and Pd were determined by electrothermal atomic absorption spectrometry. Under optimized conditions, the recovery for Zn, Cd, Pd, As, and Cu was 98, 98.5, 97.5, 98.2, and 95%, respectively, of those obtained with the wet acid digestion method.
开发了一种超声辅助浸出程序，用于测定从欧洲共同体委员会参考局（BCR）提供的人发标准参考物质（CRM 397）中的重金属元素（砷、铜、镉、铅和锌）。采用浓硝酸-30%过氧化氢（2+1）作为浸出方法。研究了不同因素对元素酸浸出的影响，如预超声处理时间（无超声搅拌）、超声处理或超声暴露时间以及超声浴温度。为了从CRM BCR 397和正常健康男性的人头皮头发样本中最大程度地提取重金属，选择了这些参数的最佳值。为检验所提方法的有效性，采用湿酸消解方法测定CRM BCR 397和头皮头发样本中的总元素浓度。浸出液和消解液中的铜和锌采用常规空气/乙炔火焰，通过火焰原子吸收光谱法测定，而砷、镉和钯则采用电热原子吸收光谱法测定。在优化条件下，锌、镉、钯、砷和铜的回收率分别为湿酸消解方法所得回收率的98%、98.5%、97.5%、98.2%和95%。
