Cedeño E, Cabrera H, Delgadillo-López A E, Delgado-Vasallo O, Mansanares A M, Calderón A, Marín E
Instituto Politécnico Nacional, Centro de Investigación en Ciencia Aplicada y Tecnología Avanzada, Legaria 694, Colonia Irrigación, CP 11500 Ciudad de México, México.
Centro Multidisciplinario de Ciencias, Instituto Venezolano de Investigaciones Científicas, Mérida 5101, Venezuela; SPIE-ICTP Anchor Research in Optics Program Laboratory, International Centre for Theoretical Physics, Trieste 34151, Italy.
Talanta. 2017 Aug 1;170:260-265. doi: 10.1016/j.talanta.2017.04.008. Epub 2017 Apr 3.
In this work, a low detection limit for hexavalent chromium in water of parts per trillions (21ng/L) was achieved using a micro-spatial thermal lens spectroscopy setup with coaxial counter-propagating pump and probe laser beams and an integrated passive optical Fabry-Perot resonator, aided with a well-established diphenyl carbazide colorimetric method. Cr-VI concentrations in the range of μg/L, i.e. well-below the toxicity thresholds in humans and animals (26 and 190mg/L respectively) and below those delimited by international regulations for drink water (~0.05-0.5mg/L), have been obtained by measurements in bottled and tap water samples. The developed thermal lens microscope is also capable to detect Cr-VI directly in potassium dichromate solutions using pump beam wavelengths within the very low optical absorption region in the visible part of the spectrum, i.e., without the use of any colorimetric method.
在这项工作中，通过使用具有同轴反向传播泵浦和探测激光束以及集成无源光学法布里 - 珀罗谐振器的微空间热透镜光谱装置，并借助成熟的二苯卡巴肼比色法，实现了对水中万亿分之一（21 ng/L）六价铬的低检测限。通过对瓶装水和自来水样品的测量，获得了微克/升范围内的六价铬浓度，即远低于人类和动物的毒性阈值（分别为26和190 mg/L）以及低于国际饮用水法规规定的限值（约0.05 - 0.5 mg/L）。所开发的热透镜显微镜还能够在光谱可见光部分的极低光吸收区域内使用泵浦光束波长，直接在重铬酸钾溶液中检测六价铬，即无需使用任何比色法。
