To compare glass samples based on their refractive index (RI) and their trace magnesium content by atomic absorption spectrophotometry (AA).

Glass fragments (half-inch square) from bottles and from automobiles. Find a junk yard and obtain samples from car headlamps and windshields.

A set of liquid refractive index standards; magnesium metal; pure lanthanum nitrate; concentrated hydrofluoric acid solution; concentrated hydrochloric acid; concentrated nitric acid

Standard Reference Material

optical microscope; sodium vapor lamp; microscope slides; flame atomic absorption spectrophotometer; ultrasonic bath; plastic centrifuge tubes

RI: For instructor (detailed) ; For student (brief)

AA: For instructor (detailed) ; For student (brief)

AA calibration curve for magnesium; magnesium content of typical glass samples; RI of typical glass samples

Inductively Coupled Plasma (ICP) - Emission Spectrophotometry (OES)

Procedure