I found the recent article by Cho and Park (Analysis of hydrogen concentration in low-alloy steel, Journal of Radioanalytical and Nuclear Chemistry 284 (2010), 533–537) most tantalizing. The authors do not give enough details for me to understand how they are able to accurately measure 0.1 μg of hydrogen (1 ppm in a 100 mg sample) in the presence of a 13 μg background, especially since the sample is “irradiated while attached to a paper filter.” They validated their measurements by comparison with ICP-AES, a claim that my colleagues in that field are unable to understand. Although hydrogen can be detected via the 656 nm line (Spectrochim. Acta 40B (1985), 177–194], since that method in general practice requires the sample to be in water solution, a detailed reference to their procedure is needed. I look forward to reading their future publications.