Question

question # 9
multiple choice
which one of the following is not measured or analyzed by spectrometry methods?

specific gravity of crystals found at the scene of the crime

identity of paint chips

employee drug screening

blood - alcohol levels

Explanation:

Spectrometry methods are used for analyzing substances based on their interaction with electromagnetic radiation. Paint chips can be analyzed by techniques like IR - spectroscopy (to identify the chemical composition of the paint binder, pigments etc.). Employee drug screening can use mass - spectrometry (to identify the presence of drug metabolites in biological samples). Blood - alcohol levels can be measured using gas - chromatography - mass - spectrometry (GC - MS) or infrared spectroscopy (as alcohol has characteristic absorption bands). However, specific gravity is a physical property (ratio of density of a substance to density of water) and is measured using methods like pycnometer (for solids) or hydrometer (for liquids) and not by spectrometry methods.

Answer:

specific gravity of crystals found at the scene of the crime