Wessels J M, Charlesworth P, Rodgers M A
Center for Photochemical Sciences, Bowling Green State University, OH 43403, USA.
Photochem Photobiol. 1995 Apr;61(4):350-2. doi: 10.1111/j.1751-1097.1995.tb08621.x.
The current trend in methodology for determining IR and near-IR absorption spectra is to employ interferometer-based instruments to replace the monochromator-based devices used heretofore. As a dispersion element, the interferometer offers major improvements in spectral resolution (Connes advantage), light throughput (Jacquinot advantage) and data acquisition through multiplexing (Felgett advantage). We have compared signal-to-noise (S/N) ratios of grating-based and interferometer-based instruments for making spectral determinations of near-IR luminescence. Our results show that under identical excitation and detector conditions the interferometer instrument easily outperforms the grating, giving a 10-fold improvement in S/N at high signal amplitude (A488nm = 0.97) and a 20-fold improvement when the signal amplitude is low (A488nm = 0.06). Although some spectral resolution is sacrificed when scan times on the Fourier transform (FT)IR are significantly shortened, the S/N ratio was found only to decrease by a factor of 2 for a 10-fold decrease in scan time. This adds to the advantages of the FTIR technique because the S/N will thus improve for the same total acquisition time.
当前用于测定红外和近红外吸收光谱的方法趋势是采用基于干涉仪的仪器来取代迄今使用的基于单色仪的设备。作为一种色散元件，干涉仪在光谱分辨率（康奈斯优势）、光通量（雅昆诺优势）以及通过多路复用进行数据采集（费尔盖特优势）方面有重大改进。我们比较了基于光栅的仪器和基于干涉仪的仪器在进行近红外发光光谱测定时的信噪比（S/N）。我们的结果表明，在相同的激发和探测器条件下，干涉仪仪器轻松超越光栅仪器，在高信号幅度（A488nm = 0.97）时信噪比提高10倍，在低信号幅度（A488nm = 0.06）时提高20倍。尽管当傅里叶变换红外光谱仪（FTIR）的扫描时间显著缩短时会牺牲一些光谱分辨率，但发现扫描时间减少10倍时，信噪比仅降低2倍。这增加了FTIR技术的优势，因为在相同的总采集时间内信噪比会因此提高。
