elementaaranalüüs

Elementaaranalüüs is a quantitative chemical analysis method used to determine the elemental composition of an organic compound. It is a fundamental technique for verifying the empirical formula of a newly synthesized or isolated substance. The process typically involves combusting a precisely weighed sample of the organic material in an oxygen-rich atmosphere.

During combustion, carbon is converted to carbon dioxide (CO2) and hydrogen is converted to water (H2O). If nitrogen is present, it is typically converted to nitrogen gas (N2). Other elements like sulfur and halogens are also converted into their respective oxides or gaseous compounds. These combustion products are then passed through specific detectors or absorption traps that quantify the amount of each element present. For example, CO2 can be absorbed by a strong base, and the amount of base consumed is directly proportional to the amount of carbon in the original sample. Similarly, water can be absorbed by a desiccant.

The results obtained from elementaaranalüüs are usually expressed as percentages by mass for each element (e.g., %C, %H, %N). These percentages are then used to calculate the empirical formula, which represents the simplest whole-number ratio of atoms in a compound. While elementaaranalüüs provides the empirical formula, it does not directly reveal the molecular formula. However, when combined with other techniques like mass spectrometry, which determines the molecular weight, the molecular formula can be accurately established. Elementaaranalüüs remains a crucial tool in organic chemistry for confirming the identity and purity of chemical compounds.