Analysis sample

from Wikipedia, the free encyclopedia

In analytical chemistry , biology or medicine, the entirety of the material to be examined is referred to as an analysis sample (usually just a sample or a material sample ) . As a chemical substance , tissue sample , or other substance mixture, this material can be gaseous (such as a car exhaust sample, an odor sample), liquid (such as drinking water samples, urine samples), solid (such as a rock sample ) or a mixture of different aggregate states ( e.g. a moist soil sample ).

Analyte, matrix and analysis solution

The analyte or analytes are those substances contained in a sample about which a statement should be made in a chemical analysis , i.e. H. which should be analyzed. As matrix (plural: matrices ) are referred to a sample of those constituents that are not analyzed. For example, if you want to determine how much chromium a nail contains, then the nail is the sample and the chromium the analyte. Iron , carbon and all other substances that may be present together form the matrix. Under certain circumstances, the matrix can make the analysis much more difficult, for example if the analyte only makes up a very small proportion of the sample or if the matrix interferes with the analysis process.

Analysis solutions are used in chemistry to examine mixtures of substances (samples) that are not naturally liquid, but must be examined with a device that can only process liquid media. For this purpose, a defined amount of the sample is dissolved in a solvent, usually water or ethanol . The resulting analysis solution is poured into the measuring device. Many measuring devices are only designed for a certain measuring range, so that it is sometimes necessary to further dilute the analysis solution in order to be able to examine it. In this case, the measurement result must be multiplied by the dilution factor in order to determine the real concentration. These analysis solutions are required, for example, for analyzes using atomic absorption spectrometers (AAS) or for radiocarbon measurements , as well as for all types of wet chemical analysis.

See also

Individual evidence

  1. ^ Daniel C. Harris: Textbook of Quantitative Analysis . Edited by Gerhard Werner and Tobias Werner. 8th, completely revised exp. Edition. Springer Spectrum, Berlin, Heidelberg 2014, ISBN 978-3-642-37788-4 .