Page 124 - Illustrated Pocket Dictionary of Chromatography

M

macroporous Refers to polymerized resins (e.g., polystyrene-
divinylbenzene) that are formed in a solvent where the monomers are
soluble but the polymer is not. The result is a high-mechanical-
stability spherical porous material that has included solvent. Removal
of the entrapped solvent results in the finished product.

macroreticular resin A resin that is cross-linked such that a
highly porous particle with large average diameter pores is produced.
(See microreticular.) These materials are used for the separation of
larger analytes and as ion-exchange supports.
make-up gas Used to help increase the flow rate of the sample
eluting from the column through the detector. This is particularly
crucial for split injection samples.

Mark–Houwink equation Defines the relationship between the
molecular weight of a polymer, MW, and the intrinsic viscosity of a
dilute solution of the polymer, [h]:
[] ¥ (MW ) a
h = K
where K and a are constants for a given polymer type and solution
composition.
mass flow detectors A destructive detector whose signal is in
part derived from the rate at which a sample moves through the detec-
tor cell. As an example, a flame-ionization detector burns a sample to
generate a signal so that if the flow through the detector were stopped
the signal would rapidly decrease to zero. (This is not the case with
a concentration detector.)

mass spectrum A plot of the ion abundance versus the mass-to-
charge ratio (m/z) that is generated in a mass spectrograph.
mass transfer The process of a compound moving between
phases (or through a given phase). Resistance to mass transfer and

Illustrated Pocket Dictionary of Chromatography, by Paul C. Sadek.
ISBN 0-471-20021-2 Copyright © 2004 John Wiley & Sons, Inc.
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