In general, infinite-age contamination can make a sample considerably older while modern contamination can make the sample significantly younger than its true age.
Regardless of the carbon dating methodology employed, be it radiometric dating or the accelerator mass spectrometry (AMS) method, a process must be done before analysis to get rid of all possible contaminants. Radiocarbon dating labs receive various materials for analysis but not all portions of the samples can be used.
There are two types of pretreatment usually applied to samples for carbon dating—physical and chemical.
Another example of a natural contaminant is plant root penetration on wood, charcoal, or soil.
Artificial contamination refers to the introduction of contaminants by man during the collection, field conservation, or packaging of the samples.
Important Note on Pretreatment – It is important to understand the pretreatments which are going to be applied to samples since they directly affect the final result.
You are welcome to contact us to discuss the pretreatment or request that we contact you after the pretreatment (and prior to dating).
Labeling of bone samples with animal glue is an example of artificial contamination.