A novel RP-HPLC refractive index detector method development and validation for determination of trace-level alcohols (un-sulfated) in sodium lauryl sulfate raw material.

The main aim of the study is to develop and validate a simple and rapid liquid chromatographic analytical method for simultaneous determination of trace level of un-sulfated alcohol impurities in sodium lauryl sulfate using high-performance liquid chromatography with a refractive index detector. The chromatographic separation was achieved using flow rate of 3.0 ml/min with a Waters Symmetry C18 (150 × 4.6 mm, 5 μm) column and 50°C as a column temperature. The mobile phase comprised milliQ water and acetonitrile in the ratio of 30:70 v/v respectively. The detection was performed using a refractive index detector at a sensitivity of 64. The resolutions among n-decanol, n-dodecanol, n-tetradecanol, n-hexadecanol, and n-heptadecanol were found to be >4. Regression analysis showed a correlation coefficient for the stated compounds of >0.999. The validated HPLC method was utilized effectively for the estimation of un-sulfated alcohols in quality control labs for commercial release of sodium lauryl sulfate.