The use of zeolite 13X as a stationary phase for direct determination of water in organic solvents by high-performance liquid chromatography

High-performance liquid chromatography (HPLC) method for direct determination of water impurities in various organic solvents using a column (50 x 4.6 mm, ID) packed with 5 mu m faujasite and methanol as an eluent was developed. Detection of the water peaks was performed by using either refractometric or indirect spectropho-tometric method at 204 nm. In the first case the limit of detection (LOD) and limit of quantitation (LOQ) were 0.001 wt% and 0.0033 wt%, respectively for a sample volume of 20 mu L. A linear calibration plot (R2 = 0.9998) for the water content between 0.01 and 9.55 wt% was obtained. The developed method was applied for the direct analysis of various polar organic solvents including acetonitrile, nitromethane, 1,4-dioxane, 2-ethoxyethanol, methanol, dimethyl sulfoxide (DMSO), ethanol and 2-propanol.

Automated summary

A HPLC method using a faujasite-packed column and methanol as eluent was developed for direct determination of water impurities in various organic solvents. Water peaks were detected by refractometry or indirect spectrophotometry at 204 nm. The method achieved a LOD and LOQ of 0.001 wt% and 0.0033 wt% respectively for a 20 μL sample volume and obtained a linear calibration plot (R2 = 0.9998) for water content between 0.01 and 9.55 wt%. The method was successfully applied to the analysis of polar organic solvents including acetonitrile, nitromethane, 1,4-dioxane, 2-ethoxyethanol, methanol, dimethyl sulfoxide (DMSO), ethanol and 2-propanol.