Yamamoto Junji, Hagiwara Yuuki
Department of Earth and Planetary Sciences, Graduate School of Science Kyushu University Nishi-ku Japan.
Graduate School of Science Hokkaido University Kita-ku Japan.
Anal Sci Adv. 2022 Oct 17;3(9-10):269-277. doi: 10.1002/ansa.202200020. eCollection 2022 Oct.
We measured Raman spectra of N fluids obtained at 0.1-25 MPa at room temperature. The NN peak in the Raman spectrum of a low-pressure N fluid is difficult to detect because of the prevalence of a group of peaks attributed to rotational vibration of N. The Raman peaks of NN and N of N fluid at 25 MPa were acquired at various exposure times. The mean values and standard deviations of the peak height ratios and peak area ones of NN and N were examined for each time. The standard deviations of the peak height ratios and peak area ones were 2.2% and 1.9%, respectively, for 20 spectra acquired with peak height of 1 million counts of N. The uncertainties are about two times higher than those predicted from the noise of a CCD. Improvement of the pixel resolution can enhance the precision of the nitrogen isotope ratios by Raman spectroscopy.
我们测量了在室温下0.1 - 25兆帕压力下获得的N流体的拉曼光谱。由于存在一组归因于N的旋转振动的峰，低压N流体拉曼光谱中的NN峰很难检测到。在25兆帕压力下，N流体的NN和N的拉曼峰是在不同的曝光时间下采集的。每次都检查了NN和N的峰高比和峰面积比的平均值和标准偏差。对于以N的峰高为100万计数采集的20个光谱，峰高比和峰面积比的标准偏差分别为2.2%和1.9%。这些不确定性比根据电荷耦合器件（CCD）的噪声预测的结果高出约两倍。像素分辨率的提高可以通过拉曼光谱增强氮同位素比的精度。
