Each instrument used in
analytical chemistry
Analytical chemistry studies and uses instruments and methods to separate, identify, and quantify matter. In practice, separation, identification or quantification may constitute the entire analysis or be combined with another method. Separati ...
has a useful working range. This is the range of
concentration
In chemistry, concentration is the abundance of a constituent divided by the total volume of a mixture. Several types of mathematical description can be distinguished: '' mass concentration'', ''molar concentration'', '' number concentration'', ...
(or mass) that can be adequately determined by the instrument, where the instrument provides a useful signal that can be related to the concentration of the
analyte
An analyte, component (in clinical chemistry), or chemical species is a substance or chemical constituent that is of interest in an analytical procedure. The purest substances are referred to as analytes, such as 24 karat gold, NaCl, water, etc. ...
.
All instruments have an upper and a lower working limit. Concentrations below the working limit do not provide enough signal to be useful, and concentrations above the working limit provide too much signal to be useful. When calibrating an instrument for use, the experimenter must be familiar with both the lower and upper working range of the chosen instrument.
Analytical chemistry
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