Hoe moleculaire waterstof in water meten — DPD-methode stap voor stap
Paul Fournier
How to measure molecular hydrogen in water? The step-by-step DPD method. 2026 reference guide, field-validated by our Lyon 7e workshop before each shipment.
Why measure instead of just believing
A manufacturer claiming 8,000 PPB without providing measurements is asking for a leap of faith. Molecular hydrogen is a dissolved gas: its concentration depends on the electrode, electrolysis time, temperature, and diffusion loss (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 method (di-ethyl-paraphenylenediamine)
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. Limitation: accuracy ±200 PPB on a visual comparator, ±50 PPB on a photometer.
2. Polarographic probe (H2Blue)
Modified Clark probe: Pt/AgCl electrode measuring the 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 (8 to 10 minutes for HYDROGENYX ELITE 9K). Water should be at 15-25°C: if too hot, H2 solubility drops (Henry's Law).
Step 2 — Sampling
Pour 5 mL of electrolyzed water into a clean test tube, immediately after the cycle ends. Work quickly: every 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 will turn 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 higher.
Step 5 — Documentation
Note date, bottle serial number, electrolysis duration, water temperature, measured value. Each HYDROGENYX ELITE 9K leaves our Lyon 7e workshop with its numbered DPD ticket.
Common sources of error
Unclean tube (chlorine residue = false positive), expired DPD reagent (fades less), water too hot (H2 already gone), delayed sampling, reading under fluorescent light (biased perception of pink).
Why 9,000 PPB is our threshold
Peer-reviewed studies (Aoki 2012, Kajiyama 2008, Song 2015) use 0.8 to 1.6 ppm. At 9,000 PPB, ELITE 9K delivers 5.6 to 11× the documented minimum dose — a margin that compensates for natural loss between cycle and ingestion. See our 7 peer-reviewed studies and manufacturing at our Lyon 7e workshop.
HYDROGENYX · Paul Fournier · France · Lyon 7e Workshop · contact@hydrogenyx.fr · 1,988 reviews 4.7/5 · 5-year warranty · 60-day money-back guarantee
