How do we determine the purity of aluminum?

The purity of aluminum can be determined through various analytical techniques. One common method is spectroscopic analysis, which includes techniques like atomic absorption spectroscopy (AAS) and inductively coupled plasma mass spectrometry (ICP-MS). These methods can detect trace elements in aluminum, providing a measure of its purity. Another method is gravimetric analysis, where impurities are chemically separated and weighed to determine their concentration. X-ray fluorescence (XRF) is also used for non-destructive testing of aluminum purity. Each method has its advantages and limitations, and the choice depends on the required level of accuracy and the specific impurities of interest.