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I am afraid you would need access to some very high-tech analytical instrumentation to perform the measurements you want to do. There are two main reasons for this:

1. The concentration of BPA that will leach into the food are very small, which means you will need very sensitive detection methods (mass spectrometry seems to be what is commonly used)

2. If indeed you want to check for leaching of BPA into food rather than something much simpler such as water, you are facing the problem of separating the many different components that are in food and that might interfere with your measurement (and that might be around in much higher concentration than the BPA) from the BPA, without losing substantial amounts of the BPA in the process.

These problems are common problems faced by analytical chemists, so it is good to become aware of them.