Certification of the reference material of water content in water saturated 1-octanol by Karl Fischer coulometry, Karl Fischer volumetry and quantitative nuclear magnetic resonance

► Quantitative NMR is firstly introduced to certify the water content CRM. ► Relative bias of coulometry and volumetry is 0.06%. ► Three methods are consistent. ► Uncertainty of water content in WSO CRM is 0.09%, less than NIST SRM 2890 (0.10%).