Graafiittiputkeen

Graafiittiputkeen, also known as graphite tube, is a crucial component in graphite furnace atomic absorption spectrometry (GFAAS). This specialized device is where the sample is introduced and subjected to a precisely controlled heating process. The graphite tube is typically made of high-purity graphite, which can withstand the extremely high temperatures required for atomization, often exceeding 2500 degrees Celsius.

The GFAAS analytical process involves several stages within the graphite tube. First, the sample is placed inside the tube and dried at a moderate temperature to remove the solvent. Following drying, the sample undergoes a charring or ashing step to eliminate organic matrix components. The final and most critical stage is atomization, where the graphite tube rapidly heats to a very high temperature, causing the analyte in the sample to decompose into free atoms. These free atoms then absorb light at their characteristic wavelengths, which is measured by the instrument's detector.

The design and material of the graphite tube are critical for successful GFAAS analysis. Factors like tube dimensions, wall thickness, and graphite purity influence the efficiency of atomization, sensitivity, and the lifespan of the tube. Different types of graphite tubes exist, including those with platforms designed to improve atomization characteristics and reduce interference. Graphite tubes are consumables and need to be replaced periodically due to degradation from repeated heating cycles and potential chemical attack. The performance of the graphite tube directly impacts the accuracy and precision of the quantitative elemental analysis performed using GFAAS.