无标样皮秒激光剥蚀电感耦合等离子体质谱快速定量分析金属镀层  

Quick standardless quantitative analysis of metallic coatings using single-spot picosecond laser ablation inductively coupled plasma mass spectrometry

作　　者：金献忠 陈建国 章超 谢健梅 JIN Xianzhong;CHEN Jianguo;ZHANG Chao;XIE Jianmei(Ningbo Academy of Science and Technology for Inspection and Quarantine,Ningbo 315012,China;Ningbo Customs District Technology Center,Ningbo 315012,China)

机构地区：[1]宁波检验检疫科学技术研究院,浙江宁波315012 [2]宁波海关技术中心,浙江宁波315012

出　　处：《电镀与涂饰》2021年第21期1671-1676,共6页Electroplating & Finishing

基　　金：海关总署(原国家质量监督检验检疫总局)科技计划项目(2017IK048)。

摘　　要：提出了一种基于皮秒激光剥蚀电感耦合等离子体质谱(psLA-ICP-MS)的无标样快速分析金属镀层中各元素含量的方法。psLA系统由实验室自己研制,激光波长266 nm,脉冲频率20 Hz,脉冲宽度30 ps,样品池8 cm^(3),气溶胶传输管路50 cm,单位脉冲剥蚀量低至20 nm,空间分辨率30μm。经与纳秒激光剥蚀(nsLA)比较,psLA剥蚀坑陡峭、边界清晰。经与nsLA-ICP-MS比较,psLA-ICP-MS的元素分馏效应和基体效应不明显,金属镀层中各元素的时间分辨图边界清晰。调谐ICP-MS,使在相同同位素丰度的情况下,低、中、高质量数的信号值趋于一致。采用单点剥蚀法采集样品中所有元素的时间分辨图,经积分获得各元素的信号值。该信号值经电离度校正和同位素丰度校正后,采用归一法求得金属镀层中各元素的含量。该方法不需要绘制校准曲线,不受激光功率和激光剥蚀量波动的影响,样品制备简单,分析成本低,效率高。选择已知值的纯银和高纯锌标准物质作为金属镀层进行方法验证,结果趋于一致。该方法适用于各类金属镀层及金属样品的快速定量分析。A method for accurate and standardless determination of the elemental composition of metallic coating was developed based on picosecond laser ablation inductively coupled plasma mass spectrometry(psLA-ICP-MS).The homemade psLA system has the following parameters:laser wavelength 266 nm,pulse frequency 20 Hz,pulse width 30 ps,ablation chamber volume 8 cm^(3),aerosol transmission distance 50 cm,ablation depth per pulse up to 20 nm,and spatial resolution 30μm.In comparison with nanosecond laser ablation(nsLA),psLA generates deeper craters with steep inner wall and clear edges.As compared with nsLA-ICP-MS,there are few elemental fractionation effect and matrix effect for psLA-ICP-MS,and all elemental transient signals are easy to be separated.Tuning the ICP-MS,the same signal responses are required for the elements with low,medium,and high mass numbers within the whole mass axis.All elemental transient signals are mapped by single-spot picosecond laser ablation,and then integrated over an interval and adjusted according to ionization degree and isotopic abundances.The relative percentages of elements in the sample are produced by directly comparing the adjusted elemental signals with the total mass spectrometric signals.The method is free from calibration curves and fluctuation in laser power and ablated mass with easy sample preparation,low cost,and high efficiency.Some certified reference materials of pure silver and highly pure zinc were analyzed by this method,and good agreement achieved between the found levels and the certified values.The method is feasible for quick and quantitative determination of all kinds of metallic coatings and pure metal samples.

关 键 词：金属镀层 皮秒激光剥蚀 电感耦合等离子体质谱 定量分析 

分 类 号：TG115.337[金属学及工艺—物理冶金]