gravimetrieke

Gravimetrieke, or gravimetric analysis, is a quantitative chemical analysis method in which the amount of an analyte is determined by measuring the mass of a solid bearing the analyte after a selective chemical reaction. The technique relies on the precise weighing of a precipitate, oxide, or other compound whose composition is known and fixed. It is valued for its direct, mass-based measurement and its independence from calibration curves.

In a typical gravimetric procedure, the sample is brought into solution, a specific reagent is added to form an insoluble product containing the analyte, and the solid is separated, washed, dried, and weighed to constant mass. The mass of the isolated precipitate is then related to the amount of analyte using stoichiometry, allowing calculation of concentration or mass percentages in the original sample. The accuracy depends on complete precipitation, minimal co-precipitation, and careful handling to avoid loss.

Common gravimetric reactions include precipitation of sulfate as barium sulfate (BaSO4), chloride as silver chloride (AgCl), or carbonate as barium carbonate (BaCO3). The choice of precipitating agent aims for high selectivity, low solubility, and a stable end compound. Some methods require ignition or firing to convert a hydrated precursor to a fixed oxide before weighing.

Advantages of gravimetric methods include high accuracy and direct traceability to mass, without relying on instrumental calibration. Limitations include long analysis times, sensitivity to interfering ions that coprecipitate or form soluble complexes, and the need for stable precipitates and careful washing and drying.

The adjective gravimetrieke in Dutch corresponds to the English gravimetric. Gravimetric analysis remains a foundational technique in inorganic and environmental chemistry, often used for determining ions in solid or solution form.