Rushing L G, Webb S F, Thompson H C
Department of Health and Human Services, Public Health Service, Food and Drug Administration, National Center for Toxicological Research, Jefferson, AR 72079-9502, USA.
J Chromatogr B Biomed Appl. 1995 Dec 1;674(1):125-31. doi: 10.1016/0378-4347(95)00285-4.
A sensitive analytical procedure for the determination of residues of leucogentian violet (LGV) and gentian violet (GV) in catfish tissue is presented. Frozen (-20 degrees C) catfish fillets were cut into chunks and then blended in a Waring blender. A 10-g amount of catfish muscle tissue was homogenized and extracted with acetonitrile-buffer, partitioned against methylene chloride, and cleaned up on tandem neutral alumina and propylsulfonic acid cation-exchange solid-phase extraction cartridges. Samples of 100 microliters (0.5 g equiv.) were chromatographed isocratically in 15 min using an acetonitrile-buffer mobile phase on a cyano phase column in-line with a post-column PbO2 oxidation reactor. The PbO2 post-column reactor efficiently oxidized the LGV to the chromatic GV permitting visible detection at 588 nm for both LGV and GV. Linearity was demonstrated with standards over the range 0.5-50 ng per injection. Recoveries of LGV and GV from catfish tissues fortified at 20, 10, and 1 ng/g were 83.1 +/- 1.2, 78.4 +/- 4.0, 84 +/- 8 and 92.7 +/- 1.8, 95.0 +/- 2.2, 93 +/- 2 (mean +/- S.D., n = 4), respectively.
