Thus, even if larger samples like RATE’s “on the order of 100 mg”  are submitted to an AMS laboratory, only about 1 mg of carbon will actually undergo analysis.Though Baumgardner calls a 1 mg sample “tiny” , it is generally considered “large” by AMS laboratories [e.g., 5, 7, 8], with enough carbon to provide ion source current for about a day.
This technique has indeed allowed use of much smaller samples and has become the dominant method of radiocarbon dating.
However, the original anticipation of 100,000-year background levels has been “unrealized due to a variety of sample processing and instrument-based experimental constraints” .
John Baumgardner, a geophysicist with expertise in tectonic modeling, presents experimental data claiming to show that all biological material contains intrinsic radiocarbon, no matter how old that material may be thought to be [1, 2].
He makes additional claims that even non-biological carbonaceous material contains intrinsic radiocarbon.
Furthermore, the instrument itself always introduces a background, similar to most other high sensitivity analytical instruments .
A sample originally containing absolutely no radiocarbon will still give a nonzero measurement from such contributions.
Muller suggested that particle accelerators be used to separate the atoms, allowing the radiocarbon atoms to be counted directly instead of waiting for them to decay.
It was hoped that this would enable dating of much smaller and perhaps much older samples.
The second is a set of new samples that the RATE team collected and sent to a leading radiocarbon AMS laboratory to be dated.
In both cases, I am convinced that the “intrinsic radiocarbon” is nothing more than contamination and instrument background.
Most radiocarbon AMS laboratories process samples using a variant of the method described by Vogel , with apparatus and processes typically optimized for samples containing about 1 mg of carbon.