Analytical Chemistry Ch.1

The first step in any chemical analysis is procuring a representative sample to measure.

Same composition everywhere (doesn't matter where you take the sample from).

One whose composition differs from place to place.

to pour off (typically leaving behind a solvent or other denser material).

A chemical substance that is the subject of chemical analysis.

A complete transfer.

A suspension of solid in a liquid.

Liquid above the packed solid.

transforming a sample into a state that is suitable for analysis (at times a tedious procedure).

Identifying what is in an unknown.

is how much is present.

(Also called a standard curve) A graph of detector response as a function of analyte concentration.

Are when known concentrations of pure substance are prepared and injected into the column, and the resulting peak is measured.

(Portions). The purpose of replica measurements (repeated measurements) is to assess the variability (uncertainty) in the analysis and to guard against a gross error in the analysis of a single aliquot (part).

differences in composition occur randomly and on a fine scale.

is collected by taking portions from the desired number of segments chosen at random.

large regions have obviously different compositions. Here a representative composite sample must be constructed.