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In this study, we have evaluated a low field limit drift tube ion mobility device for ion mobility-mass spectrometry (IM-MS) measurements that uses nitrogen as a bath gas with electrospray ionization on a modified Q-TOF instrument. We have determined reduced mobility (K0) and collision cross section (CCS) values for a group of analyte ions that have been characterized previously in other drift tube IM-MS instruments. Our determinations of CCS for this set of ions as well as for standards are in agreement with published values. Because of their importance in biophysics and pharmaceuticals, we expanded our analysis to investigate the properties of cyclodextrins in this system. We present CCS data for both positively and negatively charged cyclodextrins and, for purposes of comparison, maltodextrose ions. Our results are the first reports of these materials as negative ions. [ABSTRACT FROM AUTHOR]

2-Hydroxypropyl-beta-cyclodextrin (HPβCD) has gained recent attention as a potential therapeutic intervention in the treatment of the rare autosomal-recessive, neurodegenerative lysosomal storage disorder Niemann-Pick Disease Type C1 (NPC1). Notably, HPβCD formulations are not comprised of a single molecular species, but instead are complex mixtures of species with differing degrees of hydroxypropylation of the cyclodextrin ring. The degree of substitution is a critical aspect of the complex mixture as it influences binding to other molecules and thus could potentially modulate biological effects. VTS-270 (Kleptose HPB) and Trappsol® Cyclo™ are HPβCD products under investigation as novel treatments for NPC1. The purpose of the present work is to compare these two different products; analyses were based on ion distribution and abundance profiles using mass spectrometry methodology as a means for assessing key molecular distinctions between products. The method incorporated electrospray ionization and analysis with a linear low-field ion mobility quadrupole time-of-flight instrument. We observed that the number of hydroxypropyl groups (the degrees of substitution) are substantially different between the two products and greater in Trappsol Cyclo than in VTS-270. The principal ions of both samples are ammonium adducts. Isotope clusters for each of the major ions show doubly charged homodimers of the ammonium adducts. In addition, both products show doubly charged homodimers from adduction of both a proton and ammonium. Doubly charged heterodimers are also present, but are more intense in Trappsol Cyclo than in VTS-270. Based on the analytical differences observed between VTS-270 and Trappsol Cyclo with respect to the degree of substitution, the composition and fingerprint of the complex mixture, and the impurity profiles, these products cannot be considered to be the same; the potential biological and clinical implications of these differences are not presently known. [ABSTRACT FROM AUTHOR]