GC-MS Determination of 7 Preservatives in Granulated Drugs for Common Cold

A method of GC-MS for the determination of seven preservatives, i.e. sorbic acid , benzoic acid , dehydroacetic acid , methyl paraben , ethyl paraben , propyl paraben and butyl paraben in granulated drugs for common cold was proposed. The drug sample was acidified with HCl (1+1) solution and extracted with ethyl ether. The extracts were separated on DB-FFAP column, and determined under selected ion monitoring mode in MS. n-Undecylenic acid was used as internal standard. Linear relationships between values of peak area and mass concentration of the 7 preservatives were kept in the same range of 1.0-40.0 mg·L-1, with detection limits (3S/N) in the range of 0.03-0.30 mg·kg-1. Tests for recovery were made at the concentration levels of 5.0 and 20.0 mg·L-1 of the mixed standards, values of recovery found were in the range of 82.5%-88.5% with RSD′s (n=5) in the range of 0.80%-6.7%.