NOVEX NOTES 198 / English
Parts per million: ppm reporting basis
Editorial educational material · 16 October 2026
Understanding the question
Parts per million expresses a ratio, but the basis must be clear. A mass ratio and another concentration convention should not be silently interchanged. Reading the method and units prevents a misleading conversion.
A worked example
In a teaching table, one column uses a mass-to-mass ratio while another expresses amount per volume. The reviewer does not merge them under one ppm heading simply because both numbers are small. The denominator is part of the result, not a formatting detail.
Original editorial teaching example, not clinical trial findings.What to check
Keep the full unit definition and sample basis. Do not choose an impurity limit from an unrelated context or convert a trace-level analytical example into an assessment of clinical safety.
Source and further reading
EMA — ICH Q3C Residual solvents ↗
Educational material. The source concerns the scientific topic, not NOVEX products. This article does not verify product properties or provide administration instructions. A short guide is not a systematic review.