| S-H, Sigma-Aldrich Corporation, HPLC, colorimetry | Peroxide concentration 406.85 μM; standard deviation 13.87 |
|---|---|
| E-H, Energy Chemical, HPLC, colorimetry | Peroxide concentration 372.88 μM; standard deviation 14.71 |
| K-H, KNOWLES, HPLC, fluorescence | Peroxide concentration 0.901 μM; standard deviation 0.047 |
| K-E, KNOWLES, EL, colorimetry | Peroxide concentration 62.25 μM; standard deviation 5.95 |
| K-A, KNOWLES, AR, fluorescence | Peroxide concentration 1.279 μM; standard deviation 0.079 |
| J-H, Jinshan Chemical, HPLC, fluorescence | Peroxide concentration ~; standard deviation ~ |
| C-A, Chron Chemical, AR, colorimetry | Peroxide concentration 75.89 μM; standard deviation 5.98 |
| G-G, General Reagent, GR, fluorescence | Peroxide concentration 0.156 μM; standard deviation 0.034 |
| G-E, General Reagent, EL, fluorescence | Peroxide concentration ~; standard deviation ~ |
| A-H, Aladdin, HPLC, colorimetry | Peroxide concentration 31.14 μM; standard deviation 3.53 |
| KC-H, Kermel Chemical, HPLC, fluorescence | Peroxide concentration 0.632 μM; standard deviation 0.044 |
| KC-E, Kermel Chemical, EL, fluorescence | Peroxide concentration 0.370 μM; standard deviation 0.041 |
| M-E, Macklin, EL, colorimetry | Peroxide concentration 16.14 μM; standard deviation 3.01 |
| MT-H, Mreda Technology, HPLC, fluorescence | Peroxide concentration 0.559 μM; standard deviation 0.039 |
Tao Zhong, Jinyan Du, Yuhao Hu, Yang Shen, Haoze Yuan, Jianing Song, Junchang Guo, Wenmao Li, Zhengrong Lin, Boru Wei, Yujie Zhao, Yonghao Zheng, Chunhua Cui, Xu Deng. “The ethanol illusion: hidden peroxides as a source of radical artifacts.” ChemRxiv (). https://doi.org/10.26434/chemrxiv.15007834/v1
Values presented only in colorimetric-assay, UV–visible-absorption, fluorescence-microscopy, EPR, or XPS plots or images were not transcribed
| Ti(IV) sulfate colorimetry, evaporation | Concentrating 2 mL of ethanol to 200 μL resulted in a peroxide concentration as high as 3.26 mM |
|---|---|
| Ti(IV) sulfate colorimetry, heating | At 65 °C in the presence of oxygen, the peroxide concentration increased monotonically over time, reaching an increment of 111 μM within one week |
| EPR, S-H ethanol evaporation residue | After dropping S-H ethanol onto a glass substrate and allowing it to stand for 15 min, a robust characteristic four-line (1:2:2:1) DMPO-OH signal emerged |
| EPR, ethanol–water solution | A freshly prepared 25 % (v/v) ethanol–water solution exhibited co-existing DMPO-OH and DMPO-R signals; standing for 3 days or heating at 45 °C significantly increased signal intensity |
| EPR, FeSO₄ addition | Introducing 200 μM FeSO₄ solution into peroxide-containing ethanol in a 1:1 ratio caused immediate intense ·OH and ·R signals; HO₂· signals were detected within 5 min, and all three radical-adduct intensities increased over 15 min |
| EPR, K-E ethanol | At a peroxide concentration of 62.22 μM, heating and Fe²⁺ addition yielded analogous signals with lower intensities; no EPR signals were detected under these conditions with peroxide-free ethanol |
| EPR, 5 % (v/v) ethanol–water mixture | DMPO-OH and DMPO-R signals were observed after Fe²⁺ addition |
| XPS, control O 1s | Peaks at approximately 531.7, 532.7, and 533.8 eV |
|---|---|
| XPS, residue-covered O 1s | Peaks shifted to 531.2 and 533.3 eV with markedly increased intensities; the peak at 532.5 eV decreased slightly; a Na KLL Auger peak emerged at 536 eV |
| XPS, residue-covered C 1s | Signals at 284.8 eV and 288.6 eV increased significantly |
| XPS, residue-covered Si 2p | The signal was markedly attenuated |