For the first time we here present the unambiguous identification of the formyl radical (^•CHO) by EPR (Electron Paramagnetic Resonance) spectroscopy and mass spectrometry (MS) using DMPO (5,5-dimethyl-1-pyrroline N-oxide) as spin trap at ambient temperature without using any catalyst(s). The ^•CHO was continuously generated by UV photolysis in closed anoxic environment from pure formaldehyde (HCHO) in aqueous solution. The isotropic hyperfine structure constants of ^•CHO were determined as a_N = 15.72 G and a_H = 21.27 G. The signals were deconvoluted and split by simulation in their single adduct components: DMPO-CHO, DMPO-H and DMPO-OH. We verified our results at first using MNP (2-methyl-2-nitroso-propane) as spin trap with known literature data and then mass spectrometry. Similarly the MNP adduct components MNP-CHO, MNP-H as well as its own adduct, the MNP-2-methyl-2-propyl (MNP-MP) were deconvoluted. Due to the low signal intensities, we had to accumulate single measurements for both spin traps. Using MS we got the exact mass of the reduced ^•CHO adduct independently confirming the result of EPR detection of formyl radical.

我们首次在此展示了使用DMPO（5,5-二甲基-1-吡咯啉N-氧化物）自旋的EPR（电子顺磁共振）光谱和质谱（MS）对甲酰基（^• CHO）的明确鉴定在不使用任何催化剂的情况下在环境温度下捕集阱。所述^• CHO连续通过从在水溶液中的纯的甲醛（HCHO）封闭缺氧环境紫外光解产生。^• CHO的各向同性超细结构常数确定为_N = 15.72 G和_H= 21.27G。通过模拟对信号进行去卷积和拆分，将其分解为单个加合物成分：DMPO-CHO，DMPO-H和DMPO-OH。我们首先使用MNP（2-甲基-2-亚硝基丙烷）作为自旋阱并根据已知文献数据验证了我们的结果，然后使用质谱进行了验证。类似地，对MNP加合物组分MNP-CHO，MNP-H以及其自身的加合物MNP-2-甲基-2-丙基（MNP-MP）进行去卷积。由于信号强度低，我们不得不对两个自旋阱进行单次测量。使用质谱，我们得到了还原的^• CHO加合物的准确质量，独立地证实了EPR检测甲酰基的结果。