Abstract
A rapid and simple method of gas chromatography was studied to determine lactic acid in fermented milk.
The column employed was PEG-6000(10%) on terephthalic acid solid support (1.5m long glass column), which permits separation of lactic acid without derivatizing it into a volatile compound.
In this method it is not necessary to extract, esterify or trimethyl-silylate the sample. The column temperature was programmed from 120°C to 190°C at 6°C/min. The lactic acid was identified by a GC-MS combined system.
The fermented milk sample was added with sulfuric acid to be 0.1% (V/V) and introduced into the gas chromatograph to determine lactic acid quantitatively.
This method gave good quantitativeness for lactic acid and a long life for the column.
