Determination of malachite green and leucomalachite green in a variety of aquacultured products by liquid chromatography with tandem mass spectrometry detection.
A liquid chromatography/tandem mass spectrometry (LC/MS/MS) method was developed for determining the residues of malachite green (MG) and leucomalachite green (LMG) in a number of aquatic species. MG and its metabolite were extracted from homogenized tissues with a perchloric acid-acetonitrile solution; the extract was centrifuged; and an aliquot was taken, concentrated, and passed through a chemically bonded octadecyl C18 solid-phase extraction column. The compounds of interest were eluted with acetonitrile, and the eluate was evaporated to dryness. The residue was dissolved in acetonitrile and diluted with water in preparation for analysis by LC/MS/MS. MG and its metabolite were determined by reversed-phase LC using a Luna C18 column with an ammonium hydroxide-formic acid buffer in acetonitrile gradient and MS/MS detection using multiple reaction monitoring. Calibration curves were linear for all analyses between 5 and 500 pg injected for both analytes, with recoveries ranging from 81% for LMG to 98% for MG in salmon spiked at the 1 ng/g level. Detection limits of 0.1 ng/g for both MG and LMG were easily obtainable using the recommended method. The operational errors, interferences, and recoveries for spiked samples compared favorably with those obtained by established methodology. The recommended method is simple, rapid, and specific for monitoring residues of MG and LMG in a number of aquatic species.
Canadian Food Inspection Agency, Dartmouth Laboratory, PO Box 1060, Dartmouth, B3B 1Y9 Canada. vanderietjm@inspection.gc.ca
Jeffrey M
JM
van de Riet
Cory J
CJ
Murphy
Johanna N
JN
Pearce
Ross A
RA
Potter
B Garth
BG
Burns
D000097:Acetonitriles / Q000737:chemistry; D064753:Ammonium Hydroxide; D000814:Aniline Compounds / Q000032:analysis*; D000818:Animals; D002138:Calibration; D002853:Chromatography, Liquid / Q000379:methods*; D005504:Food Analysis / Q000379:methods; D005506:Food Contamination; D005561:Formates / Q000737:chemistry; D006878:Hydroxides / Q000737:chemistry; D015203:Reproducibility of Results; D012394:Rosaniline Dyes / Q000032:analysis*; D012474:Salmon; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*
D000097:Acetonitriles; D000814:Aniline Compounds; D005561:Formates; D006878:Hydroxides; D012394:Rosaniline Dyes; C030544:formic acid; C005095:malachite green; D064753:Ammonium Hydroxide; C015320:leucomalachite green; C032159:acetonitrile