HPLC Determination of Indole in Shrimp Meat and Its Products

Appropriate amount of sample of fresh shrimp meat (or dried shrimp meat) was taken and extracted twice with acetonitrile (20 mL). After centrifuging, the supernatants were taken and made up to 50.0 mL with acetonitrile, and used for HPLC analysis. 2-Methyl-indole was added as internal standard. The Hedera ODS-2 column and mobile phase of mixture of acetonitrile and H2O (65+35) were used for HPLC separation. Fluorescence detection (λex=270 nm, λem=340 nm) was adopted for the determination. Linearity range was found within 200 μg·L-1 of indole. Lower limit of determination (10S/N) was found as 125 μg·kg-1. Test for recovery was made by addition of standard indole solution to blank samples of fresh and dry shrimp meat as matrixes, and values of recovery found were in the range of 90.1%-104% with values of RSD′s (n=6) in the range of 1.9%-5.2%.