CAJ | 학술논문

为了提高激光诱导击穿光谱（L IBS ）技术对土壤中重金属元素的检测灵敏度，降低检测限，以国家标准土壤中Cr元素为研究对象，实验时，在LIBS装置中与样品接近的聚焦透镜下方安装一个锥形罩，锥形罩的小端面直径为20 mm ，大端面直径为45 mm ，目的是对等离子体发射信号形成空间约束，并且在一定程度上约束等离子体本身。实验得到C rⅠ425.44 nm的最佳延迟时间为1.3μs ，相对标准偏差低于10％。与无锥形空间约束的装置相比，C r的特征光谱强度增强了7％以上。以土壤中的C r在60～400μg · g -1之间的浓度建立定标曲线，有空间约束下定标曲线的线性拟合相关系数为0.99771，Cr的检测限为18.85μg · g -1，而没有空间约束下定标曲线的线性拟合相关系数为0.99122，C r的检测限为36.99μg · g -1。由此表明锥形空间约束能够提高目标元素的灵敏度和光谱强度，在L IBS技术检测土壤中C r元素时有很好的辅助作用。
위료제고격광유도격천광보（L IBS ）기술대토양중중금속원소적검측령민도，강저검측한，이국가표준토양중Cr원소위연구대상，실험시，재LIBS장치중여양품접근적취초투경하방안장일개추형조，추형조적소단면직경위20 mm ，대단면직경위45 mm ，목적시대등리자체발사신호형성공간약속，병차재일정정도상약속등리자체본신。실험득도C rⅠ425.44 nm적최가연지시간위1.3μs ，상대표준편차저우10％。여무추형공간약속적장치상비，C r적특정광보강도증강료7％이상。이토양중적C r재60～400μg · g -1지간적농도건립정표곡선，유공간약속하정표곡선적선성의합상관계수위0.99771，Cr적검측한위18.85μg · g -1，이몰유공간약속하정표곡선적선성의합상관계수위0.99122，C r적검측한위36.99μg · g -1。유차표명추형공간약속능구제고목표원소적령민도화광보강도，재L IBS기술검측토양중C r원소시유흔호적보조작용。
The present study is to improve the sensitivity of detection and reduce the limit of detection in detecting heavy metal of soil by laser induced breakdown spectroscopy (LIBS) .The Cr element of national standard soil was regarded as the research ob-ject .In the experiment ,a conical cavity with small diameter end of 20 mm and large diameter end of 45 mm respectively was in-stalled below the focusing lens near the experiment sample to mainly confine the signal transmitted by plasma and to some extent to confine the plasma itself in the LIBS setup .In detecting CrⅠ425.44 nm ,the beast delay time gained from experiment is 1.3μs ,and the relative standard deviation is below 10% .Compared with the setup of non-spatial confinement ,the spectral intensity of Cr in the soil sample was enhanced more than 7% .Calibration curve was established in the Cr concentration range from 60 to 400 μg · g -1 .Under the condition of spatial confinement ,the liner regression coefficient and the limit of detection were 0.997 71 and 18.85 μg · g -1 respectively ,however ,the regression coefficient and the limit of detection were 0.991 22 and 36.99μg · g -1 without spatial confinement .So ,this shows that conical spatial confinement can improve the sensitivity of detection and enhance the spectral intensity .And it is a good auxiliary function in detecting Cr in the soil by laser induced breakdown spectroscopy .