Pre-column derivatization GC determination for optical isomers of α-ethyl-2-O-1-pyrrolidinylacetic acid

Objective:To establish a GC with pre-column derivatization method for determination of optical purity in synthetic (S)-α-ethyl-2-O-1-pyrrolidinylacetic acid,to set up quality control of α-ethyl-2-O-1-pyrrolidinylacetic acid in production process.Methods:Methanol and SOCl2 were used as derivatization reagents.The separation was carried out on an HP chiral 10% cyclodextrin column( 30 m×0.25 mm×0.25 μm);highly pure N2 was adopted as carrier gas at the flow rate of 1 mL·min-1;the temperature for inlet port and the FID detector were both 250 ℃;the column temperature was 120-180 ℃ and raised by program;the split ratio was 15:1;the injection amount was 0.6 μL.Result:α-ethyl-2-O-1-pyrrolidinylacetic acid has good linear relationship in the concentration range of 0.2-4.0 mg· mL-1 ( r=0.999 );the detection limit(S/N=3)was 5.3 μg·mL-1;the quantitative limit(S/N=10)was 20.1 μg·mL-1;each of optical isomers was well isolated.Conclusion:This method is accurate,reliable,sensitive and suitable for optical isomer control in the synthetic process of (S)-α-ethyl-2-O-1-pyrrolidinylacetic acid.