Feasibility of Trace Alcohol Congener Detection and Identification Using Laser-Induced Breakdown Spectroscopy

In this paper, a feasible scheme is reported for the detection and identification of trace alcohol congeners that have identical elemental composition using laser-induced breakdown spectroscopy （LIBS）. In the scheme, an intensive pulsed laser is used to break down trace alcohol samples and the optical emission spectra of the induced plasma are collected for the detection and identifq ication of alcohol molecules. In order to prepare trace alcohol samples, pure ethanol or methanol is bubbled by argon carrier gas and then mixed into matrix gases. The key issue for the scheme is to constitute indices from the LIBS data of the alcohol samples. Two indices are found to be suitable for alcohol detection and identification. One is the emission intensity ratio （denoted as H/C） of the hydrogen line （653.3 nm） to the carbon line （247.9 nm） for identification and the other is the ratio of the carbon line （as C/Ar） or the hydrogen line （as H/Ar） to the argon lines （866.7 nm） for quantitative detection. The calibration experiment result shows that the index H/C is specific for alcohol congeners while almost being independent of alcohol concentration. In detail, the H/C keeps a specific constant of 34 and 23 respectively for ethanol and methanol. In the meanwhile, the C/Ar and H/Ar indices respond almost linearly to the alcohol concentration below 1300 ppm, and are therefore competent for concentration measurement. With the indices, trace alcohol concentration measurement achieves a limit of 140 ppm using a laser pulse energy of 300 mJ.     

蒸氨废液中SO2－4的测定

简要介绍SO2－4的测定方法，说明这些方法在测定蒸氨废液上清液中SO2－４时的弊端，进而提出改进措施；并对措施的实施效果进行检验。     

蒸氨废液中SO_4~(2-)的测定

简要介绍SO2 - 4的测定方法 ,说明这些方法在测定蒸氨废液上清液中SO2 - 4时的弊端 ,进而提出改进措施 ;并对措施的实施效果进行检验     

轻质纯碱中大颗粒的成分分析及形成原因探讨

对轻质纯碱中的大颗粒碱进行分类成份分析 :探讨大颗粒碱的形成原因 ,并提出解决问题的意见     

碱渣液体脱硫剂成分分析方法的探讨

氨碱法生产纯碱过程中产生大量废渣,废碱渣中的碳酸钙可与热电烟道气中的酸性氧化物二氧化硫反应,据此性质可将碱渣废液制备成液体脱硫剂,对碱渣液体脱硫剂成分选择合适的方法进行准确分析,为液体脱硫剂的制备、使用提供科学准确的数据依据。     

化学耗氧量测定条件的探讨

介绍酸性高锰酸钾法测定水中化学耗氧量的实验方法,探讨影响测定结果的因素,得出加酸量、加热时间、滴定温度、滴定速度等关键点的测定条件。     

高职院校学生素质教育探讨

文章通过分析现在高职学生素质教育的现状,探讨了素质教育目标的建设和对学生进行规范管理的实施.