Determination of 1,2-propanediol in milk by gas chromatography-mass spectrometry

A method for the detection of 1,2-propanediol in milk by gas chromatography-mass spectrometry (GC-MS) was established by optimizing pretreatment and chromatographic conditions. The results showed that the samples were extracted with acetonitrile, purified by dispersion solid-phase extraction, separated by DB-WAX chromatographic column (30 m×0.25 mm×0.25 μm) with a split ratio of 10:1, determined by GC-MS using the selective ion monitoring (SIM) mode, and quantified by the external standard method. Under these conditions, 1,2-propanediol had a good linear relationship within the mass concentration range of 1.0-50 μg/ml, with a correlation coefficient (R²)>0.999. The detection limit (LOD) of 1,2-propanediol in milk was 0.005 g/kg, and the limit of quantification (LOQ) was 0.010 g/kg. The recovery rate of standard addition was 93.67%-100.67%, and the relative standard deviation (RSD) of the precision test results was 1.23%-3.91%. This method featured simple pretreatment, strong resistance to matrix interference, accurate results, and minimal contamination and damage to the instrument. It had certain promotion value and could be used for the detection of 1,2-propanediol in milk.