CHARACTERIZATION OF HEMATOLOGY LYSING REAGENTS CONTAINING QUATERNARY AMMONIUM HALIDES USING FAST-ATOM-BOMBARDMENT MASS-SPECTROMETRY

Positive- and negative-ion fast-atom bombardment (FAB) mass spectromet ry has been employed to characterize pure dodecyl-, tetradecyl- and he xadecyl-trimethylammonium chlorides and bromides, compounds of high in terest as lysing agents in hematologic analyses. In parallel, the same approach has been used for some commercially available lysing reagent products. While in positive-ion FAB mass spectra the presence of the abundant ions corresponding to the intact quaternary ammonium cations (Q+) is accompanied by the presence of [Q2X]+ (X = Cl, Br) species, in the negative-ion mode cluster ions such as [QX2]- are the sole ionic species that are easily evident. The mechanism for the formation of [Q 2X]+ and [QX2]- species has been studied and some suggested explanatio ns are given.