Separation and determination of process-related impurities of industrial chlorpyriphos by reversed- phase high performance liquid chromatography

Samples were dissolved in the mobile phase and applied to a reversed-phase C18 column with acetonitrile/aqueous acetic acid as mobile phase and diode array detection. Typical content of chlorpyriphos was 978.8-990.6 g/kg with a RSD of 1.45%. Impurities were 0.1-2.5 g/kg with RSD of 1.63-2.56