Gas chromatography detection method of ethylene glycol, diethylene glycol and menthol in toothpaste

The invention provides a new technology for simultaneously detecting prohibited substances such as ethylene glycol and diethylene glycol, and functional component menthol in toothpaste by an internal standard method through a gas chromatograph. The method is characterized by comprising the following steps of: adopting an Agilent DB-624 chromatographic column, taking helium as carrier gas, using a flame ionization detector, taking 1,4-butanediol as internal standard substance; and split sampling. Samples are subjected to methanol extraction and ultrasonic oscillation treatment, then stewing, taking a supernatant fluid and filtering by a filtering film with 0.45mu.m, and the filtrate is the sampling solution. Retention time of the sample is used for qualitative analysis, and quantitative analysis is carried out according to a peak area ratio of each component to the internal standard substance. The method has the advantages of high sensitivity, high reproducibility, high selectivity, and strong specificity; the processing method of the samples is simple; through the internal standard method, the analysis error is further reduced; and the method is suitable for qualitatively and quantitatively analyzing ethylene glycol, diethylene glycol and menthol in the toothpaste.