Anhui Institute of Optics and Fine Mechanics, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031, China.
Science Island Branch of Graduate School, University of Science and Technology of China, Hefei 230026, China.
Sensors (Basel). 2022 Feb 16;22(4):1527. doi: 10.3390/s22041527.
Previous research revealed that isotopes C and O of exhaled CO have the potential link with ; however, the O isotope has received very little attention. We developed a sensitive spectroscopic sensor for simultaneous C, O, and O analysis of human breath CO based on mid-infrared laser direct absorption spectroscopy with an interband cascade laser (ICL) at 4.33 μm. There was a gas cell with a small volume of less than 5 mL, and the pressure in the gas cell was precisely controlled with a standard deviation of 0.0035 Torr. Moreover, real-time breath sampling and batch operation were achieved in gas inlets. The theoretical drifts for C, O, and O measurement caused by temperature were minimized to 0.017‱, 0.024‱, and 0.021‱, respectively, thanks to the precise temperature control with a standard deviation of 0.0013 °C. After absolute temperature correction, the error between the system responded -value and the reference is less than 0.3‱. According to Allan variance analysis, the system precisions for C, O, and O were 0.12‱, 0.18‱, and 0.47‱, respectively, at 1 s integration time, which were close to the real-time measurement errors of six repeated exhalations.
先前的研究表明，呼出 CO 的 C 和 O 同位素与 之间存在潜在联系；然而，O 同位素却很少受到关注。我们基于中红外激光直接吸收光谱学和 4.33 μm 的级联激光（ICL），开发了一种用于同时分析人体呼吸 CO 的 C、O 和 O 的灵敏光谱传感器。该传感器的气体池体积小于 5 mL，且气体池内的压力通过标准差为 0.0035 Torr 的标准装置精确控制。此外，在进气口实现了实时呼吸采样和批量操作。由于采用了标准差为 0.0013°C 的精确温度控制，C、O 和 O 测量的理论温度漂移分别最小化至 0.017‱、0.024‱和 0.021‱。经过绝对温度校正后，系统响应值与参考值之间的误差小于 0.3‱。根据 Allan 方差分析，在 1 s 的积分时间下，C、O 和 O 的系统精度分别为 0.12‱、0.18‱和 0.47‱，接近 6 次重复呼气的实时测量误差。
