Analysis of residual solvents in natural flavorings by headspace GC using the standard addition method.

摘要

Headspace gas chromatography using the standard addition method was developed for the simultaneous determination of organic solvents in natural flavourings. An aliquot of the sample to be tested is transferred to a 10 ml vial. To each vial, a DMSO solution containing solvents at different concentrations is added as the standard solution. The vials are kept a t 50 degrees C (for automatic injection) or 40 degrees C (for hand-operated injection) for 40 minutes. One ml of the vapour phase in each vial is injected into a gas chromatograph equipped with an Aquatic-2 columb (0.25 mm idx60m). To evaluate the method a performance study was conducted in collaboration with 10 laboratories, using oleoresin. Six solvents (methanol, 2-propanol, acetone, dichloromethane, hexane and 1,1,2-trichloroethene) were analysed for the maximum residue limits (as established in Japan's Specifications and Standards for Food Additives). Methanol and acetone exists in ginger oleoresin, so only the other 4 solvents were used when ginger was tested. Eight laboratories used automatic injection, and the remaining 2 used hand-operated injection. Statistical analyses were conducted on data obtained from 8 laboratories. Repeatability standard deviations ranged from 4.3 to 11.4 and reproducibility standard deviations ranged from 8.4 to 19.0.