激光剥蚀电感耦合等离子体质谱法中生物样品的元素分馏效应研究  

Elemental Fractionation Studies of Biological Samples Using Laser Ablation Inductively Coupled Plasma Mass Spectrometry

作　　者：李青[1,2] 张国霞[1] 陈奕睿[1] 汪正[1] 丁传贤[1] 

机构地区：[1]中国科学院上海硅酸盐研究所,上海200050 [2]中国科学院大学,北京100049

出　　处：《分析化学》2017年第6期868-873,共6页Chinese Journal of Analytical Chemistry

基　　金：国家自然科学基金项目(No.21175145);中国科学院仪器设备功能开发技术创新项目(No.Y57YQ5150G)资助~~

摘　　要：采用213 nm-纳秒激光剥蚀系统对生物基体样品的剥蚀颗粒进行研究,优化了激光剥蚀条件。在剥蚀能量为25%,束斑直径为200μm,剥蚀速率为20μm/s,频率为20 Hz,载气为700 m L He+700 m L Ar时,信号强度及稳定性最佳。以^(31)P为内标元素,最佳剥蚀条件下,考察了56个元素的相对分馏因子。结果表明,生物基体的剥蚀颗粒相较于NIST 610玻璃标样更大,达到3μm;生物基体中元素分馏效应相较于玻璃基体小,大多数元素的相对分馏因子达到1.0±0.1。探讨了生物基体中元素分馏机理,分析了生物基体相较于玻璃基体剥蚀颗粒大,而相对分馏因子未明显增大的原因。一方面可能是粒径3μm的颗粒进入电感耦合等离子体后能原子化;另一方面,大的剥蚀颗粒的富集效应相对较小。进一步对分馏效应的影响因素进行研究,发现分馏效应与激光剥蚀能量、激光频率和扫描速率相关,并且与元素的氧化物沸点负相关,与氧化物键能和电离能正相关。The ablated aerosols of biological matrix sample were studied using 213 nm nanosecond laser ablation system. The stable signal intensity and high sensitivity were obtained when the laser energy was 25 %, the spot size was 200 μm,the scan rate was 20 μm/s,the frequency was 20 Hz and th e carrier gas was 700 mL He ＋ 700 mL Ar. Relative fractionation index of 56 elements were investigated and 31P as the internal standard element was selected under the optimized laser ablation conditions. The results showed that particle size of the biological sample was 3 μm, which was larger compared with NIST 610 sample . Element fractionation in biological sample was smaller than in glass sample , and relative fractionation index of most elements attained 1.0 土 0. 1. Element fractionation mechanism of biological sample was discussed. The possible reason why the relative fractionation index in biological sample with large particle size did not significantly increase compared to the glass sample is that the 3-μm particles entered into ICP canbe atomized. On the other hand,enrichment effect for large ablation particles was relatively small. Further study of the influence factors of fractionation effect indicated that, the fractionation effect had relations with laser ablation energy, laser frequency and scan rate, negatively relation with the oxide boiling point, and positively relation with oxide bond energy and ionization energy.

关 键 词：激光剥蚀-电感耦合等离子体质谱 纳秒激光 分馏效应 生物样品 

分 类 号：O657.63[理学—分析化学]