I am not sure where the advantage for you personally is in doing this, unless you have a serious intent to act upon the outcome? Even then moving location may only partially change the background contamination profile because no two years will yield the same forage.
A full HPLC / GC analysis that would cover most of what has been eluded to in this thread will cost you probably £200+. Even as big test users for residues (1000s of tests) we can only get about £80 for a broad test suite. If you then want to add a spoilage and pathogen microbiological profile add another £60+ for a private one off. If you are serious PM me and I'll give you some lab contacts..... and no, before anyone asks, I don't provide these services directly, the expenses of analysis gear and the need for a relaible critical mass of samples with an even demand profile put paid to wide spectrum private labs some time ago, I now contract out as required.