Zheng Hongtao, Ma Jingzhi, Zhu Zhenli, Tang Zhiyong, Hu Shenghong
State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074, China; Faculty of Material Science and Chemistry, China University of Geosciences, Wuhan 430074, China.
State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074, China.
Talanta. 2015 Jan;132:106-11. doi: 10.1016/j.talanta.2014.08.070. Epub 2014 Sep 6.
In this study, a fast and simple approach to directly determinate lead in water samples by a low power dielectric barrier discharge (DBD) excitation source was developed using tungsten coil electro-thermal vaporization (WC ETV) for liquid microsample introduction. A 20 μL sample was dropped onto the WC, and then the sample went through the drying, pyrolysis, subsequently the analyte was vaporized and swept directly into the dielectric barrier discharge micro-plasma for emission, and the whole process took only 3 min. The effects of operating parameters such as plasma gas flow rate, plasma input voltage, pyrolysis current, vaporization current and interferences from concomitant elements were investigated. Under the optimal conditions, the limit of detection (LODs, 3σ) was calculated to be 7.7 μg L(-1). Repeatability, expressed as the relative standard deviation of the spectral peak height, was 4.6% (n=11) for 0.1 mg L(-1) lead standard solution. The proposed method was successfully applied to the determinations of Pb in water samples.
在本研究中，开发了一种快速简便的方法，通过低功率介质阻挡放电（DBD）激发源直接测定水样中的铅，采用钨丝线圈电热蒸发（WC ETV）进行液体微量进样。将20 μL样品滴加到钨丝线圈上，然后样品经过干燥、热解，随后分析物被蒸发并直接吹扫到介质阻挡放电微等离子体中进行发射，整个过程仅需3分钟。研究了等离子体气体流速、等离子体输入电压、热解电流、蒸发电流等操作参数以及共存元素的干扰。在最佳条件下，计算得到的检测限（LODs，3σ）为7.7 μg L⁻¹。对于0.1 mg L⁻¹的铅标准溶液，以光谱峰高的相对标准偏差表示的重复性为4.6%（n = 11）。所提出的方法成功应用于水样中铅的测定。
