Gas chromatography of isopropyl alcohol in commercial rubbing alcohols and alcohol-based hand rub solution

Date

4-2005

Degree

Bachelor of Science in Chemistry

College

College of Arts and Sciences (CAS)

Adviser/Committee Chair

Cherrie B. Pascual

Abstract

Isopropyl alcohol is a secondary alcohol commonly used for application to the skin and is popularly referred to as a rubbing alcohol. A direct injection gas chromatographic method was utilized using a polar DB-WAX capillary column and FID detector to determine the isopropanol content in commercial rubbing alcohols and alcohol-based hand rub solution. Isopropanol in samples was injected directly into a GC after adding suitable amount of acetonitrile, which was used as the internal standard. Using this method, less than 8 minutes was required to obtain results. Retention times of isopropyl alcohol and acetonitrile were found at about 5.3 and 5.6 mins, respectively. Results of the intraday and intraday analyses showed that the method exhibited high degree of precision, with coefficient of variation (CV) for the retention times of isopropanol and acetonitrile ranging from 0.1-2.4% and 0.05-2.0%, respectively, while CV of the peak area ratio of isopropanol to acetonitrile was found to range from 1.0-6.7%. Reproducible and linear chromatographic responses were obtained for the calibration curve and had correlation coefficients of 0.999 or greater. The limit of detection (LOD) was 1.6% while the limit of quantitation (LOQ) was 5.2 % (v/v). Except for the alcohol-based hand rub solution, the analysis of the commercial isopropyl alcohol samples showed good agreement between the obtained concentration of the isopropyl alcohol samples and the corresponding label claim. Modifications in the sample preparation procedure for the viscous hand nib solution should be done to improve the analysis.

Language

English

Location

UPLB Main Library Special Collections Section (USCS)

Call Number

Thesis

Document Type

Thesis

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