LC-MS/MS Determination of Residual Amounts of 7 Non-Edible Pigments in Shrimp Meat

A method of LC-MS/MS for the determination of residual amounts of 7 non-edible pigments in shrimp meat was proposed. The sample was extracted with acetonitrile,defatted by n-hexane,dried by anhydrous sodium sulfate,and cleaned up with SPE column filled with silica gel. Agilent Eclipse XDB-C8 chromatographic column was used as stationary phase. ESI and multi-reaction monitoring were adopted in MS/MS. Isotope was used as internal standard. Linearity ranges of acid orange 2,pigment red 53 and metanil yellow G were found in the range within 100 μg·L-1 and of the remainder 4 pigments were in the range within 10 μg·L-1. Values of lower limits of determination (10S/N) of 5 μg·kg-1 for acid orange 2,pigment red 53 and metanil yellow G and of 0.5 μg·kg-1 for the remainder 4 pigments. On the base of blank sample,test for recovery was made by standard addition method; values of recovery found were in the range of 53.8%-106%,with RSD′s (n=6) in the range of 2.1%-11%.