Novel Trace Analysis Systems Based on Single Picoliter Microparticles Combined with Microflow Devices

在本研究中，我们表明，一个单一的1-丁醇（BuOH）液滴可以通过红外激光照射在光学显微镜下产生的液滴可以同时被捕获的红外激光束的光学。然后将该技术与毛细管电泳系统相结合。单BuOH液滴产生的激光照射和捕获稳定，即使在渗透流的存在下。然后通过毛细管电泳分离二羟基偶氮苯铝螯合物（Al^<3+>-DHAB）或罗丹明B（Rh B），然后通过红外激光照射使溶质强制分配到单个BuOH液滴中。在RhB的情况下，染料分布到BuOH液滴中的检测下限低至10 μ <-20>mol/dm ^3，这远低于毛细管电泳的常规检测下限。激光振荡的单个RhB掺杂的微粒在空气中被证实的特征发射尖峰叠加到自发的宽发射光谱。在空气中的有机气体蒸气的存在下，从RhB掺杂的微粒的特征激光振荡尖峰调制由于在颗粒/周围介质的折射率条件的变化。本研究还扩展到激光捕获显微光谱的皮升气溶胶水滴在空气中。我们成功地进行了气溶胶水滴的温度控制激光捕获，以及在观察过冷水滴的形成低至223 K。

In the present study, we showed that a single 1-butanol (BuOH) droplet could be produced by infrared laser irradiation under an optical microscope and the droplet produced could be simultaneously trapped optically by the infrared laser beam. The technique was then combined with a capillary electrophoresis system. Single BuOH droplets were produced by laser irradiation and trapped stably even in the presence of an osmotic flow. An aluminum dihydroxyazobenzene chelate complex (Al^<3+>-DHAB) or rhodamine B (RhB) was then separated by capillary electrophoresis and the solute was then forced to distribute to single BuOH droplets produced by infrared laser irradiation. In the case of RhB, the lower detection limit of the dye distributed to the BuOH droplet was as low as 10^<-20>mol/dm^3, which was much lower than the ordinary detection limits in capillary electrophoresis.Laser oscillation in single dye-doped cation-exchange resin microspheres was also applied to ultratrace analysis. Laser oscillation of single RhB-doped microparticles under air was confirmed by characteristic emission spikes superimposed to the spontaneous broad emission spectrum. In the presence of organic gas vapor in air, the characteristic laser oscillation spikes from the RhB-doped microparticle were modulated owing to the change in the particle/surrounding medium refractive index conditions. The present study was also extended to laser trapping-microspectroscopy of picoliter aerosol water droplets in air. We succeeded in conducting temperature-controlled laser trapping of aerosol water droplets as well as in observing formation of supercooled water droplets down to 223 K.