Page 57 - Illustrated Pocket Dictionary of Chromatography

52 DESALTING

desalting The process by which simple salts are removed from
high-molecular-weight compounds.
detection The process by which an analyte is monitored as it
passes through the detector. Detection can be obtained by choosing
chemical and physical properties such as absorptivity, refraction, and
molecular weight.

detector The detector is the component of an instrument that
generates the signal from the passage of the analyte through it.

determinate errors Errors in a measurement that are not due
to random error and hence cannot be identified through statistical
analysis. Bias and offset errors are examples of determinate error.

developing chamber An airtight container that is used to hold the
developing solvent and plate in thin-layer chromatography. Note that
consistent separation requires that the chamber be saturated with the
developing solvent and that the solvent level stay beneath the point of
application (i.e., the sample spot) of the sample on the TLC plate.

The picture shows a thin-layer plate partially developed. The solvent level is the
dark line running near the bottom of the plate. The solvent from is the gray line
about 75% of the way up the plate. The sample spot has moved well up the plate
and has resolved into two spots, a smaller leading and a larger trailing.