Why Nitrogen ≠ Protein Matters

The melamine lesson.

Kjeldahl and Dumas measure all nitrogen in a sample — protein nitrogen plus non-protein nitrogen from urea, nitrates, ammonia and free amino acids — then multiply by a conversion factor (typically 6.25) to estimate protein. Any nitrogen-containing substance inflates the result. The 2008 melamine adulteration of infant formula illustrated what this means in practice: melamine is 66% nitrogen by mass, so adding it to milk made the protein reading appear normal while the milk contained none. SPRINT uses a specific dye-binding technique that tags protein and ignores non-protein nitrogen — the result is a true protein measurement.

Industries

Wherever protein content is specified, priced or regulated.

Related Products

The food composition testing picture.

Fat analysis, no calibration or solvents.

Measure true protein, not total nitrogen

KjeldahlSPRINT
What it measuresTotal nitrogenTrue protein
Time1–2 hours3 minutes
Hazardous chemicalsConcentrated H₂SO₄, catalysts, fume scrubbing, distillationNone
WasteHazardousNone
InfrastructureDedicated fume installation requiredBench-top
Adulteration detectionCannot detect nitrogen-based adulterantsUnaffected by non-protein nitrogen
Industries Served

Where the SPRINT is put to work.

Food & Beverage
FAQs

Questions we are asked about the SPRINT.

Talk to our applications team about the SPRINT

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