Tanikkul Sumalee, Jakmunee Jaroon, Rayanakorn Mongkon, Grudpan Kate, Marquardt Brian J, Gross Gwen M, Prazen Bryan J, Burgess Lloyd W, Christian Gary D, Synovec Robert E
Faculty of Science, Research and Development and Department of Chemistry, Institute of Science and Technology, Chiang Mai University, Chiang Mai, Thailand.
Talanta. 2003 Mar 10;59(4):809-16. doi: 10.1016/S0039-9140(02)00623-9.
A novel Raman sensor using a liquid-core optical waveguide is reported, implementing a Teflon-AF 2400 tube filled with water. An aqueous analyte mixture of benzene, toluene and p-xylene was introduced using a 1000 microl sample loop to the liquid-core waveguide (LCW) sensor and the analytes were preconcentrated on the inside surface of the waveguide tubing. The analytes were then eluted from the waveguide using an acetonitrile-water solvent mixture injected via a 30 microl eluting solvent loop. The preconcentration factor was experimentally determined to be 14-fold, in reasonable agreement with the theoretical preconcentration factor of 33 based upon the sample volume to elution volume ratio. Raman spectra of benzene, toluene and p-xylene were obtained during elution. It was found that analytically useful Raman signals for benzene, toluene and p-xylene were obtained at 992, 1004 and 1206 cm(-1), respectively. The relative standard deviation of the method was 3% for three replicate measurements. The limit of detection (LOD) was determined to be 730 ppb (parts per billion by volume) for benzene, exceptional for a system that does not resort to surface enhancement or resonance Raman approaches. The Raman spectra of these test analytes were evaluated for qualitative and quantitative analysis utility.
报道了一种使用液芯光波导的新型拉曼传感器，该传感器采用填充水的聚四氟乙烯-AF 2400管。使用1000微升进样环将苯、甲苯和对二甲苯的水性分析物混合物引入液芯光波导（LCW）传感器，分析物在波导管内表面进行预浓缩。然后使用通过30微升洗脱溶剂环注入的乙腈-水混合溶剂从波导中洗脱分析物。通过实验确定预浓缩因子为14倍，与基于进样体积与洗脱体积比的理论预浓缩因子33合理一致。在洗脱过程中获得了苯、甲苯和对二甲苯的拉曼光谱。结果发现，分别在992、1004和1206 cm(-1)处获得了对苯、甲苯和对二甲苯具有分析用途的拉曼信号。该方法的相对标准偏差为三次重复测量的3%。苯的检测限（LOD）确定为730 ppb（体积十亿分之一），对于一个不采用表面增强或共振拉曼方法的系统来说非常出色。对这些测试分析物的拉曼光谱进行了定性和定量分析实用性评估。
