Allen, J. L., Meinertz, J. R., and Gofus, J. E., 1992, Determination of malachite
green and its leuco form in water: Journal of Official Analytical Chemists
International, v. 75, no. 4, p. 646-649.

Abstract

Liquid chromatographic (lc) analysis can detect malachite green residues in water at
less than 10 mu-g/l.  Water samples were concentrated on disposable diol columns,
eluted with 0.05m P-toluene-sulfonic acid in methanol, and determined by
reversed-phase lc.  When combined with a lead oxide postcolumn reactor, the lc
method can simultaneously determine both leuco and chromatic forms of malachite
green. Recoveries averaged 95.4% For the chromatic form and 57.3% For the leuco
form of malachite green oxalate and leuco malachite green in spiked pond water
samples.  Recoveries of the carbinol form of malachite green (an equilibrium product
of the dye in water) from spiked tap water samples averaged 98.6%.  Recoveries of
leuco malachite green were low and ph-dependent.