摘要
植物修复是一种绿色有吸引力的重金属污染修复技术。了解重金属在植物体内不同部位的分布,有助于深入了解重金属植物修复的分子机制。激光诱导击穿光谱技术(LIBS)在元素原位快速分析时拥有突出的技术优势,尤其是具备无需复杂样品前处理、可对固体样品直接分析的突出特点,目前元素扫描成像是LIBS技术的重要研究及应用方向。设计并搭建了基于纳秒脉冲激光器的元素成像LIBS装置,系统光斑分辨率50μm,样品移动步距为100μm,成像分析速度为6.25 mm2·min-1,装置可实现自动化扫描,满足实际分析需求,系统采用多通道平面光栅光谱仪,光谱范围180~800 nm,目标元素光谱经基线扣除,峰面积拟合及归一化处理后绘制分布热图,并以伪彩呈现样品不同区域的元素分布。以豌豆为水培植物模型,利用所搭建的元素成像LIBS装置开展豌豆植株的在体原位元素成像分析,分析了Ni、 Cu、 Cr及Pb重金属在植物体内的差异性分布,并研究了上述四种重金属的吸收途径。结果显示,该元素成像装置可以对植物体内存在的C、 Mg、 Fe、 Ca、 Na、 K等主要基体元素进行有效分析,经过重金属胁迫后,豌豆植物体内存在明显的重金属累积且不同重金属在植株中呈现不同的分布趋势,镍离子在胚轴、胚芽部位大量存在,与镍离子分布不同的是,植株大量吸收铜离子并富集在根部初生结构中;重金属铬在豌豆根的中部和胚芽、胚轴大量积累,而重金属铅则大量富集在胚轴、胚芽中,根尖的含量最少。该研究表明,元素成像LIBS技术可实现对植物体内多种重金属的在体同时分析,这对辅助研究环境水体重金属污染植物修复的机理有意义,同时可为植物生理学和生态毒理学等领域的相关研究提供装置和新方法。
Phytoremediation is a green and attractive technique for remediating heavy metal pollution.Understanding the distribution of heavy metals in different plant parts can provide insight into the molecular mechanisms of heavy metal phytoremediation.Laser-induced breakdown spectroscopy(LIBS)has outstanding technical advantages for the rapid in situ analysis of elements,especially for the direct analysis of solid samples without complex sample pre-treatment.Elemental scanning imaging is currently an important research and application direction of LIBS technology.A nanosecond pulsed laser-based elemental imaging LIBS device was developed with a spot resolution of 50μm,a sample movement step of 100μm and an imaging analysis speed of 6.25 mm 2·min-1.The spectra of the target elements were normalized by baseline deduction,peak area fitting and normalization to produce a distribution thermogram with a pseudo-color representation of the elemental distribution in different regions of the sample.The in situ elemental imaging of pea plants was carried out using a hydroponic model,and the in situ elemental imaging of Ni,Cu,Cr and Pb were carried out using the imaging LIBS device.The results show that the device can effectively analyze the major matrix elements,such as C,Mg,Fe,Ca,Na and K,present in the plant and that after heavy metal stress,there is a significant accumulation of heavy metals in pea plants and different distribution trends of different heavy metals in the plant.Different from the distribution of nickel ions,the plant absorbed many copper ions and enriched it in the primordial root structures.The chromium accumulatedin the middle of the pea roots andin the germ and embryonic axis.However,large amounts of heavy metal lead was enrichedin the germ and embryonic axis,with the least amount in the root tip.This study shows that the elemental imaging LIBS technique enables the simultaneous in vivo analysis of multiple heavy metals in plants,which has implications for aiding the study of the mechanisms of phytoremediationin environmental waters.The imaging LIBS is a potential deviceand new method for related research in plant physiology and ecotoxicology.
作者
汤泉
钟敏嘉
殷鹏鲲
张志
陈珍明
吴桂容
林庆宇
TANG Quan;ZHONG Min-jia;YIN Peng-kun;ZHANG Zhi;CHEN Zhen-ming;WU Gui-rong;LIN Qing-yu(Guangxi Key Laboratory of Calcium Carbonate Resources Comprehensive Utilization(Hezhou University),College of Material and Chemical Engineering,Hezhou 542899,China;Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education,College of Life Sciences,Sichuan University,Chengdu 610064,China;College of Food and Biological Engineering,Hezhou University,Hezhou 542899,China;School of Mechanical Engineering,Sichuan University,Chengdu 610064,China)
出处
《光谱学与光谱分析》
SCIE
EI
CAS
CSCD
北大核心
2023年第5期1485-1488,共4页
Spectroscopy and Spectral Analysis
基金
国家自然科学基金项目(31760163)
广西碳酸钙资源综合利用重点实验室开放课题(HZXYKFKT201901)
贺州学院教授科研启动项目(HZUJS201707)资助。
关键词
重金属污染
LIBS
生物积累
空间分布
元素成像
Heavy metal
Laser-induced breakdown spectroscopy
Bioaccumulation
Spatial distribution
Element imaging
作者简介
汤泉,1973年生,贺州学院材料与化学工程学院高级实验师,e-mail:tangquan010@126.com;通讯作者:吴桂容,e-mail:hzwgr510@163.com;通讯作者:林庆宇,e-mail:qylin@scu.edu.cn。
