使用宽调谐扫频外腔量子级联激光器对气相酒精混合物进行定量同位素测量。

Quantitative isotopic measurements of gas-phase alcohol mixtures using a broadly tunable swept external cavity quantum cascade laser.

机构信息

Pacific Northwest National Laboratory, Richland, WA 99352, USA.

出版信息

Analyst. 2017 Jun 26;142(13):2354-2362. doi: 10.1039/c7an00223h.

Abstract

A swept-ECQCL is used for broadband IR spectroscopy of isotopic mixtures of CHOH, CHOD, CHCHOH, and CHCHOD in a static gas cell over a wavelength range of 9.5 to 10.4 μm. A weighted least squares fitting approach with quantitative library spectra illustrates that significant spectral congestion does not negatively impact the ability for in situ quantification of large isotopic species in a mixture. The noise equivalent concentrations for CHOH, CHOD, CHCHOH, and CHCHOD are 19 ppbv m, 28 ppbv m, 450 ppbv m, and 350 ppbv m respectively for a 50 seconds integration time. Based on the observed NECs, isotopic precisions of 0.07‰ and 0.79‰ for a 50 s integration time are calculated for measurements of the [MeOD]/[MeOH] and [EtOD]/[EtOH] isotope ratios, respectively, for the species concentrations in the gas cell.

摘要

扫频 ECQCL 用于在静态气体池中对 CHOH、CHOD、CHCHOH 和 CHCHOD 的同位素混合物进行宽带红外光谱测量，波长范围为 9.5 至 10.4μm。使用带有定量库谱的加权最小二乘拟合方法表明，大量同位素物种在混合物中的原位定量能力不会因光谱严重重叠而受到负面影响。对于 50 秒积分时间，CHOH、CHOD、CHCHOH 和 CHCHOD 的噪声等效浓度（NEC）分别为 19、28、450 和 350 ppbv m。基于观察到的 NEC，对于气体池中物种浓度的[MeOD]/[MeOH]和[EtOD]/[EtOH]同位素比的测量，分别计算出 50 秒积分时间的同位素精度为 0.07‰和 0.79‰。