Rapid determination of sudan dyes in chilli power by online solid phase extraction-high performance liquid chromatography

A novel method was developed for the rapid determination of sudan dyes in chilli power by online solid-phase extraction coupled to high liquid performance chromatography(online SPE-HPLC). Chilli power was extracted with acetonitrile. Then the extract was centrifuged and filtered. After that,1 m L of extract was injected into online SPE system by autosampler and delivered to the SPE column for purification and enrichment using loading pump. After clean-up step,the online SPE column was switched to the analytical flow path by valve switching and the analytes were back flushed to the analytical column using analytical pump for the further determination. Under the optimized conditions,good linearities were obtained in the range from 1 ng/m L to200 ng/m L for the four sudan dyes,with correlation coefficients above 0.9996. The limits of detection for all the analytes ranged from 1.0 ng/g to 1.95 ng/g. The method recoveries of four analytes at three spiked levels ranged between 86.2% and 101.6%,with relative standard deviations less than 6.18%. The proposed method was simple,rapid,accurate and reliable,and could be applied to the rapid determination of sudan dyes in chilli power.