Spectra of X-ray absorption near edge structure of nucleotides in water solution around nitrogen K-edge region

Ukai, Masatoshi*; Yokoya, Akinari; Fujii, Kentaro; Saito, Yuji  

We present the total photoelectron yields from nucleotides in water solution in the region around nitrogen K-edge. The experiment is carried out at the BL-23SU, SPring-8, using the soft X-rays in the energy region of 400 eV, so called "water window" region or just above. The liquid thin water jet (20m) containing nucleotide is intersected by a focused synchrotron-radiation beam, 100(v)100(h)m in a vacuum chamber. The photoelectrons ejected from the jet are collected by a channel electron multiplier. We show the first evidence of the spectrum of total photoelectron yields of DNA related compound, deoxy-5'-guanosine mono-phosphoric acid (dGMP), in solution. The spectrum shares some characteristic features with that for solid dGMP. Nitrogen atoms only exist in the guanine site, so that the spectral similarities can be explained by the hydrophobic property of the base site. The spectra for the other nucleotides will be also reported.