The Source — the HYDROGENYX Journal
How to measure molecular hydrogen in water — DPD method step by step
Paul Fournier
How to measure molecular hydrogen in water? The DPD method step-by-step. 2026 Reference Guide, applied by us in France: each batch is tested with DPD reagent (video recorded measurement) before being put on sale.
Why measure rather than believe
A manufacturer announcing 8,000 PPB without providing a measurement is asking you for a leap of faith. Molecular hydrogen is a dissolved gas: its concentration depends on the electrode, electrolysis time, temperature, and loss through diffusion (H2 escapes from an open container in a few minutes). Without measurement, the displayed value is a theoretical manufacturer's value, not the value actually delivered in your glass.
Available methods
1. DPD (di-ethyl-paraphenylenediamine) method
Colorimetric method recognized by the Molecular Hydrogen Foundation (Tyler LeBaron). DPD reagent turns pink in the presence of dissolved H2; a visual comparator or photometer reads the concentration in PPB. Advantages: inexpensive (~€3 per test), portable, readable in 30 seconds. Limit: ±200 PPB accuracy on a visual comparator, ±50 PPB on a photometer.
2. Polarographic probe (H2Blue)
Modified Clark probe: Pt/AgCl electrode measuring current induced by H2. Accuracy ±20 PPB, continuous reading. Disadvantage: requires monthly calibration and costs €600 to €900 depending on the model. Laboratory reference.
3. Gas Chromatography (GC-TCD)
Absolute reference. Accuracy ±1 PPB. Reserved for laboratories (equipment > €25,000). Used to validate other methods.
Step-by-step DPD protocol
Step 1 — Preparation
Start the electrolysis cycle of your bottle (5 to 10 minutes for HYDROGENYX Flask). The water should be at 15-25°C: if too hot, H2 solubility decreases (Henry's Law).
Step 2 — Sampling
Pour 5 mL of electrolyzed water into a clean test tube, immediately after the end of the cycle. Work quickly: each minute of air exposure results in a loss of ~100 to 300 PPB.
Step 3 — Reaction
Add 1 sachet of DPD reagent (or 2 drops of liquid reagent), shake for 5 seconds. The solution turns more or less intense pink.
Step 4 — Reading
Compare the hue to the provided visual comparator (0-15,000 PPB) or read with a photometer at 528 nm. Approximate conversion: pale pink ≈ 1,500 PPB, medium pink ≈ 5,000 PPB, saturated magenta ≈ 9,000 PPB and more.
Step 5 — Documentation
Note date, bottle serial number, electrolysis duration, water temperature, value read. Each HYDROGENYX batch is tested with DPD reagent (video recorded measurement) before being put on sale; a DPD kit is available online (~€20) for you to check at home.
Frequent sources of error
Unclean tube (chlorine residue = false positive), expired DPD reagent (fades less strongly), water too hot (H2 already gone), delayed sampling, reading under fluorescent light (biased perception of pink).
Why 9,000 PPB is our threshold
Studies published in peer-reviewed journals (Aoki 2012, Kajiyama 2008) use 0.8 to 1.6 ppm. At 9,000 PPB (manufacturer's data), the HYDROGENYX Flask largely delivers the concentration used in these studies — a margin that compensates for natural loss between cycle and ingestion. See our 7 key studies and our quality control in France.
HYDROGENYX · French brand · Customer service and warranty in France · contact@hydrogenyx.fr · 5-year warranty · 60-day money-back guarantee
HYDROGENYX Flask
The hydrogen ritual, ready in 5 minutes.
Up to ~9,000 ppb of dissolved molecular hydrogen (manufacturer's data), verifiable at home with a DPD test. 400 ml, touch screen, wireless charging base included.
60-day money-back guarantee · 5-year cell warranty · 4× Klarna
The HYDROGENYX Flask is a water preparation device, not a medical device. It does not prevent, treat, or cure any disease.
To go further: the science of hydrogen · the comparison · the FAQ
