- Matrix (chemical analysis)
In chemical analysis, matrix refers to the components of a sample other than the analyte. The matrix can have a considerable effect on the way the analysis is conducted and the quality of the results obtained; such effects are called matrix effects. For example, the ionic strength of the solution can have an effect on the activity coefficients of the analytes. The most common approach for accounting for matrix effects is to build a calibration curve using standard samples with known analyte concentration and which try to approximate the matrix of the sample as much as possible. This is especially important for solid samples where there is a strong matrix influence. In cases with complex or unknown matrices, the standard addition method can be used. In this technique, the response of the sample is measured and recorded, for example, using an electrode selective for the analyte. Then, a small volume of standard solution is added and the response is measured again. Ideally, the standard addition should increase the analyte concentration by a factor of 1.5 to 3, and several additions should be averaged. The volume of standard solution should be small enough to disturb the matrix as little as possible.
- Extraction (chemistry)
- ^ IUPAC, Compendium of Chemical Terminology, 2nd ed. (the "Gold Book") (1997). Online corrected version: (1989) "Matrix (in analysis)".
- ^ a b F. W. Fifield, P. J. Haines. Environmental Analytical Chemistry. Blackwell Publishing, 2000, p. 4-5. ISBN 0632053836.
- ^ a b Harris, D. C. Quantitative Chemical Analysis, 4th ed. Freeman, 1995, pp.194, 404. ISBN 0716725988.
- ^ IUPAC, Compendium of Chemical Terminology, 2nd ed. (the "Gold Book") (1997). Online corrected version: (1989) "Matrix effect".
- ^ Marco Aurelio Zezzi Arruda. Trends in Sample Preparation. Nova Publishers, 2006, p. 15-18. ISBN 1600211186.
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